//
// Copyright (c) ZeroC, Inc. All rights reserved.
//

#include <Slice/PythonUtil.h>
#include <Slice/Checksum.h>
#include <Slice/Util.h>
#include <IceUtil/IceUtil.h>
#include <IceUtil/StringUtil.h>
#include <climits>
#include <iterator>

using namespace std;
using namespace Slice;
using namespace IceUtil;
using namespace IceUtilInternal;

namespace
{

string
getEscapedParamName(const OperationPtr& p, const string& name)
{
    ParamDeclList params = p->parameters();

    for(ParamDeclList::const_iterator i = params.begin(); i != params.end(); ++i)
    {
        if((*i)->name() == name)
        {
            return name + "_";
        }
    }
    return name;
}

}

namespace Slice
{
namespace Python
{

class MetaDataVisitor : public ParserVisitor
{
public:

    virtual bool visitUnitStart(const UnitPtr&);
    virtual bool visitModuleStart(const ModulePtr&);
    virtual void visitClassDecl(const ClassDeclPtr&);
    virtual bool visitClassDefStart(const ClassDefPtr&);
    virtual bool visitExceptionStart(const ExceptionPtr&);
    virtual bool visitStructStart(const StructPtr&);
    virtual void visitOperation(const OperationPtr&);
    virtual void visitDataMember(const DataMemberPtr&);
    virtual void visitSequence(const SequencePtr&);
    virtual void visitDictionary(const DictionaryPtr&);
    virtual void visitEnum(const EnumPtr&);
    virtual void visitConst(const ConstPtr&);

private:

    //
    // Validates sequence metadata.
    //
    StringList validateSequence(const string&, const string&, const TypePtr&, const StringList&);

    //
    // Checks a definition that doesn't currently support Python metadata.
    //
    void reject(const ContainedPtr&);

    StringSet _history;
};

//
// ModuleVisitor finds all of the Slice modules whose include level is greater
// than 0 and emits a statement of the following form:
//
// _M_Foo = Ice.openModule('Foo')
//
// This statement allows the code generated for this translation unit to refer
// to types residing in those included modules.
//
class ModuleVisitor : public ParserVisitor
{
public:

    ModuleVisitor(Output&, set<string>&);

    virtual bool visitModuleStart(const ModulePtr&);

private:

    Output& _out;
    set<string>& _history;
};

//
// CodeVisitor generates the Python mapping for a translation unit.
//
class CodeVisitor : public ParserVisitor
{
public:

    CodeVisitor(IceUtilInternal::Output&, set<string>&);

    virtual bool visitModuleStart(const ModulePtr&);
    virtual void visitModuleEnd(const ModulePtr&);
    virtual void visitClassDecl(const ClassDeclPtr&);
    virtual bool visitClassDefStart(const ClassDefPtr&);
    virtual bool visitExceptionStart(const ExceptionPtr&);
    virtual bool visitStructStart(const StructPtr&);
    virtual void visitSequence(const SequencePtr&);
    virtual void visitDictionary(const DictionaryPtr&);
    virtual void visitEnum(const EnumPtr&);
    virtual void visitConst(const ConstPtr&);

private:

    //
    // Emit Python code for the class operations
    //
    void writeOperations(const ClassDefPtr&);

    //
    // Return a Python symbol for the given parser element.
    //
    string getSymbol(const ContainedPtr&, const string& = "", const string& = "");

    //
    // Emit Python code to assign the given symbol in the current module.
    //
    void registerName(const string&);

    //
    // Emit the tuple for a Slice type.
    //
    void writeType(const TypePtr&);

    //
    // Write an initializer value for a given type.
    //
    void writeInitializer(const DataMemberPtr&);

    //
    // Add a value to a hash code.
    //
    void writeHash(const string&, const TypePtr&, int&);

    //
    // Write Python metadata as a tuple.
    //
    void writeMetaData(const StringList&);

    //
    // Convert an operation mode into a string.
    //
    string getOperationMode(Slice::Operation::Mode);

    struct MemberInfo
    {
        string fixedName;
        bool inherited;
        DataMemberPtr dataMember;
    };
    typedef list<MemberInfo> MemberInfoList;

    //
    // Write a member assignment statement for a constructor.
    //
    void writeAssign(const MemberInfo&);

    //
    // Write a constant value.
    //
    void writeConstantValue(const TypePtr&, const SyntaxTreeBasePtr&, const string&);

    //
    // Write constructor parameters with default values.
    //
    void writeConstructorParams(const MemberInfoList&);

    void collectClassMembers(const ClassDefPtr&, MemberInfoList&, bool);
    void collectExceptionMembers(const ExceptionPtr&, MemberInfoList&, bool);

    typedef vector<string> StringVec;

    StringVec stripMarkup(const string&);

    void writeDocstring(const string&, const string& = "");
    void writeDocstring(const string&, const DataMemberList&);
    void writeDocstring(const string&, const EnumeratorList&);

    typedef map<string, string> StringMap;
    struct OpComment
    {
        StringVec description;
        StringMap params;
        string returns;
        StringMap exceptions;
    };
    bool parseOpComment(const string&, OpComment&);

    enum DocstringMode { DocSync, DocAsync, DocAsyncBegin, DocAsyncEnd, DocDispatch, DocAsyncDispatch };

    void writeDocstring(const OperationPtr&, DocstringMode, bool);

    Output& _out;
    set<string>& _moduleHistory;
    list<string> _moduleStack;
    set<string> _classHistory;
};

}
}

static string
lookupKwd(const string& name)
{
    //
    // Keyword list. *Must* be kept in alphabetical order.
    //
    static const string keywordList[] =
    {
        "None", "and", "assert", "break", "class", "continue", "def", "del", "elif", "else", "except", "exec",
        "finally", "for", "from", "global", "if", "import", "in", "is", "lambda", "not", "or", "pass",
        "print", "raise", "return", "self", "try", "while", "yield"
    };
    bool found =  binary_search(&keywordList[0],
                                &keywordList[sizeof(keywordList) / sizeof(*keywordList)],
                                name);
    return found ? "_" + name : name;
}

//
// Split a scoped name into its components and return the components as a list of (unscoped) identifiers.
//
static vector<string>
splitScopedName(const string& scoped)
{
    assert(scoped[0] == ':');
    vector<string> ids;
    string::size_type next = 0;
    string::size_type pos;
    while((pos = scoped.find("::", next)) != string::npos)
    {
        pos += 2;
        if(pos != scoped.size())
        {
            string::size_type endpos = scoped.find("::", pos);
            if(endpos != string::npos)
            {
                ids.push_back(scoped.substr(pos, endpos - pos));
            }
        }
        next = pos;
    }
    if(next != scoped.size())
    {
        ids.push_back(scoped.substr(next));
    }
    else
    {
        ids.push_back("");
    }

    return ids;
}

static string
getDictLookup(const ContainedPtr& cont, const string& suffix = "", const string& prefix = "")
{
    string scope = Slice::Python::scopedToName(cont->scope());
    assert(!scope.empty());

    string package = Slice::Python::getPackageMetadata(cont);
    if(!package.empty())
    {
        scope = package + "." + scope;
    }

    return "'" + suffix + Slice::Python::fixIdent(cont->name() + prefix) + "' not in _M_" + scope + "__dict__";
}

//
// ModuleVisitor implementation.
//
Slice::Python::ModuleVisitor::ModuleVisitor(Output& out, set<string>& history) :
    _out(out), _history(history)
{
}

bool
Slice::Python::ModuleVisitor::visitModuleStart(const ModulePtr& p)
{
    if(p->includeLevel() > 0)
    {
        string abs = getAbsolute(p);
        if(_history.count(abs) == 0)
        {
            //
            // If this is a top-level module, then we check if it has package metadata.
            // If so, we need to emit statements to open each of the modules in the
            // package before we can open this module.
            //
            if(UnitPtr::dynamicCast(p->container()))
            {
                string pkg = getPackageMetadata(p);
                if(!pkg.empty())
                {
                    vector<string> v;
                    splitString(pkg, ".", v);
                    string mod;
                    for(vector<string>::iterator q = v.begin(); q != v.end(); ++q)
                    {
                        mod = mod.empty() ? *q : mod + "." + *q;
                        if(_history.count(mod) == 0)
                        {
                            _out << nl << "_M_" << mod << " = Ice.openModule('" << mod << "')";
                            _history.insert(mod);
                        }
                    }
                }
            }

            _out << sp << nl << "# Included module " << abs;
            _out << nl << "_M_" << abs << " = Ice.openModule('" << abs << "')";
            _history.insert(abs);
        }
    }

    return true;
}

//
// CodeVisitor implementation.
//
Slice::Python::CodeVisitor::CodeVisitor(Output& out, set<string>& moduleHistory) :
    _out(out),
    _moduleHistory(moduleHistory)
{
}

bool
Slice::Python::CodeVisitor::visitModuleStart(const ModulePtr& p)
{
    //
    // As each module is opened, we emit the statement
    //
    // __name__ = 'Foo'
    //
    // This renames the current module to 'Foo' so that subsequent
    // type definitions have the proper fully-qualified name.
    //
    // We also emit the statement
    //
    // _M_Foo = Ice.openModule('Foo')
    //
    // This allows us to create types in the module Foo.
    //
    string abs = getAbsolute(p);
    _out << sp << nl << "# Start of module " << abs;
    if(_moduleHistory.count(abs) == 0) // Don't emit this more than once for each module.
    {
        //
        // If this is a top-level module, then we check if it has package metadata.
        // If so, we need to emit statements to open each of the modules in the
        // package before we can open this module.
        //
        if(UnitPtr::dynamicCast(p->container()))
        {
            string pkg = getPackageMetadata(p);
            if(!pkg.empty())
            {
                vector<string> v;
                splitString(pkg, ".", v);
                string mod;
                for(vector<string>::iterator q = v.begin(); q != v.end(); ++q)
                {
                    mod = mod.empty() ? *q : mod + "." + *q;
                    if(_moduleHistory.count(mod) == 0) // Don't emit this more than once for each module.
                    {
                        _out << nl << "_M_" << mod << " = Ice.openModule('" << mod << "')";
                        _moduleHistory.insert(mod);
                    }
                }
            }
        }
        _out << nl << "_M_" << abs << " = Ice.openModule('" << abs << "')";
        _moduleHistory.insert(abs);
    }
    _out << nl << "__name__ = '" << abs << "'";

    writeDocstring(p->comment(), "_M_" + abs + ".__doc__ = ");

    _moduleStack.push_front(abs);
    return true;
}

void
Slice::Python::CodeVisitor::visitModuleEnd(const ModulePtr&)
{
    assert(!_moduleStack.empty());
    _out << sp << nl << "# End of module " << _moduleStack.front();
    _moduleStack.pop_front();

    if(!_moduleStack.empty())
    {
        _out << sp << nl << "__name__ = '" << _moduleStack.front() << "'";
    }
}

void
Slice::Python::CodeVisitor::visitClassDecl(const ClassDeclPtr& p)
{
    //
    // Emit forward declarations.
    //
    string scoped = p->scoped();
    if(_classHistory.count(scoped) == 0)
    {
        _out << sp << nl << "if " << getDictLookup(p) << ':';
        _out.inc();

        if(!p->isInterface() || p->isLocal())
        {
            _out << nl << "_M_" << getAbsolute(p, "_t_") << " = IcePy.declareValue('" << scoped << "')";
        }

        ClassDefPtr def = p->definition();
        if(!p->isLocal() && (p->isInterface() || (def && def->allOperations().size())))
        {
            _out << nl << "_M_" << getAbsolute(p, "_t_", "Disp") << " = IcePy.declareClass('" << scoped << "')";
            _out << nl << "_M_" << getAbsolute(p, "_t_", "Prx") << " = IcePy.declareProxy('" << scoped << "')";
        }
        _out.dec();
        _classHistory.insert(scoped); // Avoid redundant declarations.
    }
}

void
Slice::Python::CodeVisitor::writeOperations(const ClassDefPtr& p)
{
    OperationList ops = p->operations();
    if(!ops.empty())
    {
        //
        // Emit a placeholder for each operation.
        //
        for(OperationList::iterator oli = ops.begin(); oli != ops.end(); ++oli)
        {
            string fixedOpName = fixIdent((*oli)->name());
            if(!p->isLocal())
            {
                if((*oli)->hasMarshaledResult())
                {
                    string name = (*oli)->name();
                    name[0] = static_cast<char>(toupper(static_cast<unsigned char>(name[0])));
                    _out << sp;
                    _out << nl << "\"\"\"";
                    _out << nl << "Immediately marshals the result of an invocation of " << (*oli)->name()
                         << nl << "and returns an object that the servant implementation must return"
                         << nl << "as its result."
                         << nl << "Arguments:"
                         << nl << "result -- The result (or result tuple) of the invocation."
                         << nl << "current -- The Current object passed to the invocation."
                         << nl << "Returns: An object containing the marshaled result.";
                    _out << nl << "\"\"\"";
                    _out << nl << "@staticmethod";
                    _out << nl << "def " << name << "MarshaledResult(result, current):";
                    _out.inc();
                    _out << nl << "return IcePy.MarshaledResult(result, _M_" << getAbsolute(p) << "._op_"
                        << (*oli)->name() << ", current.adapter.getCommunicator().getImpl(), current.encoding)";
                    _out.dec();
                }

                _out << sp << nl << "def " << fixedOpName << "(self";

                ParamDeclList params = (*oli)->parameters();

                for(ParamDeclList::iterator pli = params.begin(); pli != params.end(); ++pli)
                {
                    if(!(*pli)->isOutParam())
                    {
                        _out << ", " << fixIdent((*pli)->name());
                    }
                }

                if(!p->isLocal())
                {
                    const string currentParamName = getEscapedParamName(*oli, "current");
                    _out << ", " << currentParamName << "=None";
                }
                _out << "):";
                _out.inc();

                writeDocstring(*oli, DocAsyncDispatch, false);

                _out << nl << "raise NotImplementedError(\"servant method '" << fixedOpName << "' not implemented\")";
                _out.dec();
            }
            else
            {
                _out << sp << nl << "def " << fixedOpName << "(self";

                ParamDeclList params = (*oli)->parameters();

                for(ParamDeclList::iterator pli = params.begin(); pli != params.end(); ++pli)
                {
                    if(!(*pli)->isOutParam())
                    {
                        _out << ", " << fixIdent((*pli)->name());
                    }
                }
                if(!p->isLocal())
                {
                    const string currentParamName = getEscapedParamName(*oli, "current");
                    _out << ", " << currentParamName << "=None";
                }
                _out << "):";
                _out.inc();
                writeDocstring(*oli, DocDispatch, p->isLocal());
                _out << nl << "raise NotImplementedError(\"method '" << fixedOpName << "' not implemented\")";
                _out.dec();
            }
        }
    }
}

bool
Slice::Python::CodeVisitor::visitClassDefStart(const ClassDefPtr& p)
{
    bool isLocal = p->isLocal();
    bool isInterface = p->isInterface();
    bool isAbstract = isInterface || p->allOperations().size() > 0; // Don't use isAbstract() - see bug 3739

    string scoped = p->scoped();
    string type = getAbsolute(p, "_t_");
    string classType = getAbsolute(p, "_t_", "Disp");
    string abs = getAbsolute(p);
    string className = isLocal || isInterface ? fixIdent(p->name()) : isAbstract ? fixIdent(p->name() + "Disp") : "None";
    string classAbs = isInterface ? getAbsolute(p) : getAbsolute(p, "", "Disp");
    string valueName = (isInterface && !isLocal) ? "Ice.Value" : fixIdent(p->name());
    string prxAbs = getAbsolute(p, "", "Prx");
    string prxName = fixIdent(p->name() + "Prx");
    string prxType = getAbsolute(p, "_t_", "Prx");
    ClassList bases = p->bases();
    ClassDefPtr base;

    if(!bases.empty() && !bases.front()->isInterface())
    {
        base = bases.front();
    }

    //
    // Define a class type for Value types or local classes.
    //
    if(isLocal || !isInterface)
    {
        _out << sp << nl << "if " << getDictLookup(p) << ':';
        _out.inc();
        _out << nl << "_M_" << abs << " = Ice.createTempClass()";
        _out << nl << "class " << valueName << '(';
        if(isLocal)
        {
            if(bases.empty())
            {
                _out << "object";
            }
            else
            {
                for(ClassList::const_iterator q = bases.begin(); q != bases.end(); ++q)
                {
                    if(q != bases.begin())
                    {
                        _out << ", ";
                    }
                    _out << getSymbol(*q);
                }
            }
        }
        else
        {
            if(bases.empty() || bases.front()->isInterface())
            {
                _out << "Ice.Value";
            }
            else
            {
                _out << getSymbol(bases.front());
            }
        }
        _out << "):";

        _out.inc();

        writeDocstring(p->comment(), p->dataMembers());

        //
        // __init__
        //
        _out << nl << "def __init__(self";
        MemberInfoList allMembers;
        collectClassMembers(p, allMembers, false);
        writeConstructorParams(allMembers);
        _out << "):";
        _out.inc();
        if(!base && !p->hasDataMembers() && (!isAbstract || !isLocal))
        {
            _out << nl << "pass";
        }
        else
        {
            if(isAbstract && isLocal)
            {
                _out << nl << "if Ice.getType(self) == _M_" << abs << ':';
                _out.inc();
                _out << nl << "raise RuntimeError('" << abs << " is an abstract class')";
                _out.dec();
            }
            if(base)
            {
                _out << nl << getSymbol(base) << ".__init__(self";
                for(MemberInfoList::iterator q = allMembers.begin(); q != allMembers.end(); ++q)
                {
                    if(q->inherited)
                    {
                        _out << ", " << q->fixedName;
                    }
                }
                _out << ')';
            }
            for(MemberInfoList::iterator q = allMembers.begin(); q != allMembers.end(); ++q)
            {
                if(!q->inherited)
                {
                    writeAssign(*q);
                }
            }
        }
        _out.dec();

        if(!isLocal)
        {
            //
            // ice_id
            //
            _out << sp << nl << "def ice_id(self):";
            _out.inc();
            _out << nl << "return '" << scoped << "'";
            _out.dec();

            //
            // ice_staticId
            //
            _out << sp << nl << "@staticmethod";
            _out << nl << "def ice_staticId():";
            _out.inc();
            _out << nl << "return '" << scoped << "'";
            _out.dec();
        }
        else
        {
            writeOperations(p);
        }

        //
        // __str__
        //
        _out << sp << nl << "def __str__(self):";
        _out.inc();
        _out << nl << "return IcePy.stringify(self, _M_" << type << ")";
        _out.dec();
        _out << sp << nl << "__repr__ = __str__";

        _out.dec();

        if(_classHistory.count(scoped) == 0 && p->canBeCyclic())
        {
            //
            // Emit a forward declaration for the class in case a data member refers to this type.
            //
            _out << sp << nl << "_M_" << type << " = IcePy.declareValue('" << scoped << "')";
        }
        DataMemberList members = p->dataMembers();
        _out << sp << nl << "_M_" << type << " = IcePy.defineValue('" << scoped << "', " << valueName
             << ", " << p->compactId() << ", ";
        writeMetaData(p->getMetaData());
        const bool preserved = p->hasMetaData("preserve-slice") || p->inheritsMetaData("preserve-slice");
        _out << ", " << (preserved ? "True" : "False") << ", " << (isInterface ? "True" : "False") << ", ";
        if(!base)
        {
            _out << "None";
        }
        else
        {
            _out << "_M_" << getAbsolute(base, "_t_");
        }
        _out << ", (";
        //
        // Members
        //
        // Data members are represented as a tuple:
        //
        //   ('MemberName', MemberMetaData, MemberType, Optional, Tag)
        //
        // where MemberType is either a primitive type constant (T_INT, etc.) or the id of a constructed type.
        //
        if(members.size() > 1)
        {
            _out.inc();
            _out << nl;
        }
        bool isProtected = p->hasMetaData("protected");
        for(DataMemberList::iterator r = members.begin(); r != members.end(); ++r)
        {
            if(r != members.begin())
            {
                _out << ',' << nl;
            }
            _out << "('";
            if(isProtected || (*r)->hasMetaData("protected"))
            {
                _out << '_';
            }
            _out << fixIdent((*r)->name()) << "', ";
            writeMetaData((*r)->getMetaData());
            _out << ", ";
            writeType((*r)->type());
            _out << ", " << ((*r)->optional() ? "True" : "False") << ", "
                 << ((*r)->optional() ? (*r)->tag() : 0) << ')';
        }
        if(members.size() == 1)
        {
            _out << ',';
        }
        else if(members.size() > 1)
        {
            _out.dec();
            _out << nl;
        }
        _out << "))";
        _out << nl << valueName << "._ice_type = _M_" << type;

        registerName(valueName);

        _out.dec();
    }
    else if(!isLocal && isInterface)
    {
        _out << sp << nl << "_M_" << type << " = IcePy.defineValue('" << scoped << "', Ice.Value, -1, ";
        writeMetaData(p->getMetaData());
        _out << ", False, True, None, ())";
    }

    if(!isLocal && isAbstract)
    {
        _out << sp << nl << "if " << getDictLookup(p, "", "Prx") << ':';
        _out.inc();

        // Define the proxy class
        _out << nl << "_M_" << prxAbs << " = Ice.createTempClass()";
        _out << nl << "class " << prxName << '(';

        {
            vector<string> baseClasses;
            for(ClassList::const_iterator q = bases.begin(); q != bases.end(); ++q)
            {
                ClassDefPtr d = *q;
                if(d->isInterface() || d->allOperations().size() > 0)
                {
                    baseClasses.push_back(getSymbol(*q, "", "Prx"));
                }
            }

            if(baseClasses.empty())
            {
                _out << "Ice.ObjectPrx";
            }
            else
            {
                vector<string>::const_iterator q = baseClasses.begin();
                while(q != baseClasses.end())
                {
                    _out << *q;

                    if(++q != baseClasses.end())
                    {
                        _out << ", ";
                    }
                }
            }
        }
        _out << "):";
        _out.inc();

        OperationList ops = p->operations();
        for(OperationList::iterator oli = ops.begin(); oli != ops.end(); ++oli)
        {
            string fixedOpName = fixIdent((*oli)->name());
            if(fixedOpName == "checkedCast" || fixedOpName == "uncheckedCast")
            {
                fixedOpName.insert(0, "_");
            }
            TypePtr ret = (*oli)->returnType();
            ParamDeclList paramList = (*oli)->parameters();
            string inParams;

            for(ParamDeclList::const_iterator q = paramList.begin(); q != paramList.end(); ++q)
            {
                if(!(*q)->isOutParam())
                {
                    if(!inParams.empty())
                    {
                        inParams.append(", ");
                    }
                    inParams.append(fixIdent((*q)->name()));
                }
            }

            _out << sp;
            writeDocstring(*oli, DocSync, false);
            _out << nl << "def " << fixedOpName << "(self";
            if(!inParams.empty())
            {
                _out << ", " << inParams;
            }
            const string contextParamName = getEscapedParamName(*oli, "context");
            _out << ", " << contextParamName << "=None):";
            _out.inc();
            _out << nl << "return _M_" << classAbs << "._op_" << (*oli)->name() << ".invoke(self, ((" << inParams;
            if(!inParams.empty() && inParams.find(',') == string::npos)
            {
                _out << ", ";
            }
            _out << "), " << contextParamName << "))";
            _out.dec();

            //
            // Async operations.
            //
            _out << sp;
            writeDocstring(*oli, DocAsync, false);
            _out << nl << "def " << (*oli)->name() << "Async(self";
            if(!inParams.empty())
            {
                _out << ", " << inParams;
            }
            _out << ", " << contextParamName << "=None):";
            _out.inc();
            _out << nl << "return _M_" << classAbs << "._op_" << (*oli)->name() << ".invokeAsync(self, ((" << inParams;
            if(!inParams.empty() && inParams.find(',') == string::npos)
            {
                _out << ", ";
            }
            _out << "), " << contextParamName << "))";
            _out.dec();

            _out << sp;
            writeDocstring(*oli, DocAsyncBegin, false);
            _out << nl << "def begin_" << (*oli)->name() << "(self";
            if(!inParams.empty())
            {
                _out << ", " << inParams;
            }
            _out << ", _response=None, _ex=None, _sent=None, " << contextParamName << "=None):";
            _out.inc();
            _out << nl << "return _M_" << classAbs << "._op_" << (*oli)->name() << ".begin(self, ((" << inParams;
            if(!inParams.empty() && inParams.find(',') == string::npos)
            {
                _out << ", ";
            }
            _out << "), _response, _ex, _sent, " << contextParamName << "))";
            _out.dec();

            _out << sp;
            writeDocstring(*oli, DocAsyncEnd, false);
            _out << nl << "def end_" << (*oli)->name() << "(self, _r):";
            _out.inc();
            _out << nl << "return _M_" << classAbs << "._op_" << (*oli)->name() << ".end(self, _r)";
            _out.dec();
        }

        _out << sp << nl << "@staticmethod";
        _out << nl << "def checkedCast(proxy, facetOrContext=None, context=None):";
        _out.inc();
        _out << nl << "return _M_" << prxAbs << ".ice_checkedCast(proxy, '" << scoped << "', facetOrContext, context)";
        _out.dec();

        _out << sp << nl << "@staticmethod";
        _out << nl << "def uncheckedCast(proxy, facet=None):";
        _out.inc();
        _out << nl << "return _M_" << prxAbs << ".ice_uncheckedCast(proxy, facet)";
        _out.dec();

        //
        // ice_staticId
        //
        _out << sp << nl << "@staticmethod";
        _out << nl << "def ice_staticId():";
        _out.inc();
        _out << nl << "return '" << scoped << "'";
        _out.dec();

        _out.dec(); // end prx class

        _out << nl << "_M_" << prxType << " = IcePy.defineProxy('" << scoped << "', " << prxName << ")";

        registerName(prxName);

        // Define the servant class
        _out << sp << nl << "_M_" << classAbs << " = Ice.createTempClass()";
        _out << nl << "class " << className << '(';
        {
            vector<string> baseClasses;
            for(ClassList::const_iterator q = bases.begin(); q != bases.end(); ++q)
            {
                ClassDefPtr d = *q;
                if(d->isInterface() || d->allOperations().size() > 0)
                {
                    baseClasses.push_back(getSymbol(*q, "", d->isInterface() ? "" : "Disp"));
                }
            }

            if(baseClasses.empty())
            {
                _out << "Ice.Object";
            }
            else
            {
                vector<string>::const_iterator q = baseClasses.begin();
                while(q != baseClasses.end())
                {
                    _out << *q;

                    if(++q != baseClasses.end())
                    {
                        _out << ", ";
                    }
                }
            }
        }
        _out << "):";

        _out.inc();

        //
        // ice_ids
        //
        ClassList allBases = p->allBases();
        StringList ids;
        transform(allBases.begin(), allBases.end(), back_inserter(ids), IceUtil::constMemFun(&Contained::scoped));
        StringList other;
        other.push_back(scoped);
        other.push_back("::Ice::Object");
        other.sort();
        ids.merge(other);
        ids.unique();
        _out << sp << nl << "def ice_ids(self, current=None):";
        _out.inc();
        _out << nl << "return (";
        for(StringList::iterator q = ids.begin(); q != ids.end(); ++q)
        {
            if(q != ids.begin())
            {
                _out << ", ";
            }
            _out << "'" << *q << "'";
        }
        _out << ')';
        _out.dec();

        //
        // ice_id
        //
        _out << sp << nl << "def ice_id(self, current=None):";
        _out.inc();
        _out << nl << "return '" << scoped << "'";
        _out.dec();

        //
        // ice_staticId
        //
        _out << sp << nl << "@staticmethod";
        _out << nl << "def ice_staticId():";
        _out.inc();
        _out << nl << "return '" << scoped << "'";
        _out.dec();

        writeOperations(p);

        //
        // __str__
        //
        _out << sp << nl << "def __str__(self):";
        _out.inc();
        _out << nl << "return IcePy.stringify(self, _M_" << getAbsolute(p, "_t_", "Disp") << ")";
        _out.dec();
        _out << sp << nl << "__repr__ = __str__";

        _out.dec();

        _out << sp << nl << "_M_" << classType << " = IcePy.defineClass('" << scoped << "', " << className
             << ", ";
        writeMetaData(p->getMetaData());
        _out << ", ";
        if(!base || (!base->isInterface() && base->allOperations().size() == 0))
        {
            _out << "None";
        }
        else
        {
            _out << "_M_" << getAbsolute(base, "_t_", "Disp");
        }
        _out << ", (";
        //
        // Interfaces
        //
        int interfaceCount = 0;
        for(ClassList::const_iterator q = bases.begin(); q != bases.end(); ++q)
        {
            if((*q)->isInterface())
            {
                if(interfaceCount > 0)
                {
                    _out << ", ";
                }
                _out << "_M_" << getAbsolute(*q, "_t_", "Disp");
                ++interfaceCount;
            }
        }
        if(interfaceCount == 1)
        {
            _out << ',';
        }
        _out << "))";
        _out << nl << className << "._ice_type = _M_" << classType;

         //
        // Define each operation. The arguments to the IcePy.Operation constructor are:
        //
        // 'opName', Mode, SendMode, AMD, Format, MetaData, (InParams), (OutParams), ReturnParam, (Exceptions)
        //
        // where InParams and OutParams are tuples of type descriptions, and Exceptions
        // is a tuple of exception type ids.
        //
        if(!ops.empty())
        {
            _out << sp;
        }
        for(OperationList::iterator s = ops.begin(); s != ops.end(); ++s)
        {
            ParamDeclList params = (*s)->parameters();
            ParamDeclList::iterator t;
            int count;
            string format;
            switch((*s)->format())
            {
            case DefaultFormat:
                format = "None";
                break;
            case CompactFormat:
                format = "Ice.FormatType.CompactFormat";
                break;
            case SlicedFormat:
                format = "Ice.FormatType.SlicedFormat";
                break;
            }

            _out << nl << className << "._op_" << (*s)->name() << " = IcePy.Operation('" << (*s)->name() << "', "
                << getOperationMode((*s)->mode()) << ", " << getOperationMode((*s)->sendMode()) << ", "
                << ((p->hasMetaData("amd") || (*s)->hasMetaData("amd")) ? "True" : "False") << ", "
                << format << ", ";
            writeMetaData((*s)->getMetaData());
            _out << ", (";
            for(t = params.begin(), count = 0; t != params.end(); ++t)
            {
                if(!(*t)->isOutParam())
                {
                    if(count > 0)
                    {
                        _out << ", ";
                    }
                    _out << '(';
                    writeMetaData((*t)->getMetaData());
                    _out << ", ";
                    writeType((*t)->type());
                    _out << ", " << ((*t)->optional() ? "True" : "False") << ", "
                         << ((*t)->optional() ? (*t)->tag() : 0) << ')';
                    ++count;
                }
            }
            if(count == 1)
            {
                _out << ',';
            }
            _out << "), (";
            for(t = params.begin(), count = 0; t != params.end(); ++t)
            {
                if((*t)->isOutParam())
                {
                    if(count > 0)
                    {
                        _out << ", ";
                    }
                    _out << '(';
                    writeMetaData((*t)->getMetaData());
                    _out << ", ";
                    writeType((*t)->type());
                    _out << ", " << ((*t)->optional() ? "True" : "False") << ", "
                        << ((*t)->optional() ? (*t)->tag() : 0) << ')';
                    ++count;
                }
            }
            if(count == 1)
            {
                _out << ',';
            }
            _out << "), ";
            TypePtr returnType = (*s)->returnType();
            if(returnType)
            {
                //
                // The return type has the same format as an in/out parameter:
                //
                // MetaData, Type, Optional?, OptionalTag
                //
                _out << "((), ";
                writeType(returnType);
                _out << ", " << ((*s)->returnIsOptional() ? "True" : "False") << ", "
                     << ((*s)->returnIsOptional() ? (*s)->returnTag() : 0) << ')';
            }
            else
            {
                _out << "None";
            }
            _out << ", (";
            ExceptionList exceptions = (*s)->throws();
            for(ExceptionList::iterator u = exceptions.begin(); u != exceptions.end(); ++u)
            {
                if(u != exceptions.begin())
                {
                    _out << ", ";
                }
                _out << "_M_" << getAbsolute(*u, "_t_");
            }
            if(exceptions.size() == 1)
            {
                _out << ',';
            }
            _out << "))";

            string deprecateMetadata;
            if((*s)->findMetaData("deprecate", deprecateMetadata) || p->findMetaData("deprecate", deprecateMetadata))
            {
                string msg;
                string::size_type pos = deprecateMetadata.find(':');
                if(pos != string::npos && pos < deprecateMetadata.size() - 1)
                {
                    msg = deprecateMetadata.substr(pos + 1);
                }
                _out << nl << className << "._op_" << (*s)->name() << ".deprecate(\"" << msg << "\")";
            }
        }

        registerName(className);
        _out.dec();
    }

    if(_classHistory.count(scoped) == 0)
    {
        _classHistory.insert(scoped); // Avoid redundant declarations.
    }

    return false;
}

bool
Slice::Python::CodeVisitor::visitExceptionStart(const ExceptionPtr& p)
{
    string scoped = p->scoped();
    string abs = getAbsolute(p);
    string name = fixIdent(p->name());

    _out << sp << nl << "if " << getDictLookup(p) << ':';
    _out.inc();
    _out << nl << "_M_" << abs << " = Ice.createTempClass()";
    _out << nl << "class " << name << '(';
    ExceptionPtr base = p->base();
    string baseName;
    if(base)
    {
        baseName = getSymbol(base);
        _out << baseName;
    }
    else if(p->isLocal())
    {
        _out << "Ice.LocalException";
    }
    else
    {
        _out << "Ice.UserException";
    }
    _out << "):";
    _out.inc();

    DataMemberList members = p->dataMembers();

    writeDocstring(p->comment(), members);

    //
    // __init__
    //
    _out << nl << "def __init__(self";
    MemberInfoList allMembers;
    collectExceptionMembers(p, allMembers, false);
    writeConstructorParams(allMembers);
    _out << "):";
    _out.inc();
    if(!base && members.empty())
    {
        _out << nl << "pass";
    }
    else
    {
        if(base)
        {
            _out << nl << baseName << ".__init__(self";
            for(MemberInfoList::iterator q = allMembers.begin(); q != allMembers.end(); ++q)
            {
                if(q->inherited)
                {
                    _out << ", " << q->fixedName;
                }
            }
            _out << ')';
        }
        for(MemberInfoList::iterator q = allMembers.begin(); q != allMembers.end(); ++q)
        {
            if(!q->inherited)
            {
                writeAssign(*q);
            }
        }
    }
    _out.dec();

    //
    // __str__
    //
    _out << sp << nl << "def __str__(self):";
    _out.inc();
    _out << nl << "return IcePy.stringifyException(self)";
    _out.dec();
    _out << sp << nl << "__repr__ = __str__";

    //
    // _ice_id
    //
    _out << sp << nl << "_ice_id = '" << scoped << "'";

    _out.dec();

    //
    // Emit the type information.
    //
    string type = getAbsolute(p, "_t_");
    _out << sp << nl << "_M_" << type << " = IcePy.defineException('" << scoped << "', " << name << ", ";
    writeMetaData(p->getMetaData());
    const bool preserved = p->hasMetaData("preserve-slice") || p->inheritsMetaData("preserve-slice");
    _out << ", " << (preserved ? "True" : "False") << ", ";
    if(!base)
    {
        _out << "None";
    }
    else
    {
         _out << "_M_" << getAbsolute(base, "_t_");
    }
    _out << ", (";
    if(members.size() > 1)
    {
        _out.inc();
        _out << nl;
    }
    //
    // Data members are represented as a tuple:
    //
    //   ('MemberName', MemberMetaData, MemberType, Optional, Tag)
    //
    // where MemberType is either a primitive type constant (T_INT, etc.) or the id of a constructed type.
    //
    for(DataMemberList::iterator dmli = members.begin(); dmli != members.end(); ++dmli)
    {
        if(dmli != members.begin())
        {
            _out << ',' << nl;
        }
        _out << "('" << fixIdent((*dmli)->name()) << "', ";
        writeMetaData((*dmli)->getMetaData());
        _out << ", ";
        writeType((*dmli)->type());
        _out << ", " << ((*dmli)->optional() ? "True" : "False") << ", "
             << ((*dmli)->optional() ? (*dmli)->tag() : 0) << ')';
    }
    if(members.size() == 1)
    {
        _out << ',';
    }
    else if(members.size() > 1)
    {
        _out.dec();
        _out << nl;
    }
    _out << "))";
    _out << nl << name << "._ice_type = _M_" << type;

    registerName(name);

    _out.dec();

    return false;
}

bool
Slice::Python::CodeVisitor::visitStructStart(const StructPtr& p)
{
    string scoped = p->scoped();
    string abs = getAbsolute(p);
    string name = fixIdent(p->name());
    DataMemberList members = p->dataMembers();
    MemberInfoList memberList;

    {
        for(DataMemberList::iterator q = members.begin(); q != members.end(); ++q)
        {
            memberList.push_back(MemberInfo());
            memberList.back().fixedName = fixIdent((*q)->name());
            memberList.back().inherited = false;
            memberList.back().dataMember = *q;
        }
    }

    _out << sp << nl << "if " << getDictLookup(p) << ':';
    _out.inc();
    _out << nl << "_M_" << abs << " = Ice.createTempClass()";
    _out << nl << "class " << name << "(object):";
    _out.inc();

    writeDocstring(p->comment(), members);

    _out << nl << "def __init__(self";
    writeConstructorParams(memberList);
    _out << "):";
    _out.inc();
    for(MemberInfoList::iterator r = memberList.begin(); r != memberList.end(); ++r)
    {
        writeAssign(*r);
    }
    _out.dec();

    //
    // Only generate __hash__ and the comparison operators if this structure type
    // is a legal dictionary key type.
    //
    bool containsSequence = false;
    if(Dictionary::legalKeyType(p, containsSequence))
    {
        _out << sp << nl << "def __hash__(self):";
        _out.inc();
        _out << nl << "_h = 0";
        int iter = 0;
        for(MemberInfoList::iterator r = memberList.begin(); r != memberList.end(); ++r)
        {
            string s = "self." + r->fixedName;
            writeHash(s, r->dataMember->type(), iter);
        }
        _out << nl << "return _h % 0x7fffffff";
        _out.dec();

        //
        // Rich operators.  __lt__, __le__, __eq__, __ne__, __gt__, __ge__
        //

        _out << sp << nl << "def __compare(self, other):";
        _out.inc();
        _out << nl << "if other is None:";
        _out.inc();
        _out << nl << "return 1";
        _out.dec();
        _out << nl << "elif not isinstance(other, _M_" << abs << "):";
        _out.inc();
        _out << nl << "return NotImplemented";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        for(MemberInfoList::iterator r = memberList.begin(); r != memberList.end(); ++r)
        {
            //
            // The None value is not orderable in Python 3.
            //
            _out << nl << "if self." << r->fixedName << " is None or other." << r->fixedName << " is None:";
            _out.inc();
            _out << nl << "if self." << r->fixedName << " != other." << r->fixedName << ':';
            _out.inc();
            _out << nl << "return (-1 if self." << r->fixedName << " is None else 1)";
            _out.dec();
            _out.dec();
            _out << nl << "else:";
            _out.inc();
            _out << nl << "if self." << r->fixedName << " < other." << r->fixedName << ':';
            _out.inc();
            _out << nl << "return -1";
            _out.dec();
            _out << nl << "elif self." << r->fixedName << " > other." << r->fixedName << ':';
            _out.inc();
            _out << nl << "return 1";
            _out.dec();
            _out.dec();
        }
        _out << nl << "return 0";
        _out.dec();
        _out.dec();

        _out << sp << nl << "def __lt__(self, other):";
        _out.inc();
        _out << nl << "r = self.__compare(other)";
        _out << nl << "if r is NotImplemented:";
        _out.inc();
        _out << nl << "return r";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        _out << nl << "return r < 0";
        _out.dec();
        _out.dec();

        _out << sp << nl << "def __le__(self, other):";
        _out.inc();
        _out << nl << "r = self.__compare(other)";
        _out << nl << "if r is NotImplemented:";
        _out.inc();
        _out << nl << "return r";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        _out << nl << "return r <= 0";
        _out.dec();
        _out.dec();

        _out << sp << nl << "def __gt__(self, other):";
        _out.inc();
        _out << nl << "r = self.__compare(other)";
        _out << nl << "if r is NotImplemented:";
        _out.inc();
        _out << nl << "return r";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        _out << nl << "return r > 0";
        _out.dec();
        _out.dec();

        _out << sp << nl << "def __ge__(self, other):";
        _out.inc();
        _out << nl << "r = self.__compare(other)";
        _out << nl << "if r is NotImplemented:";
        _out.inc();
        _out << nl << "return r";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        _out << nl << "return r >= 0";
        _out.dec();
        _out.dec();

        _out << sp << nl << "def __eq__(self, other):";
        _out.inc();
        _out << nl << "r = self.__compare(other)";
        _out << nl << "if r is NotImplemented:";
        _out.inc();
        _out << nl << "return r";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        _out << nl << "return r == 0";
        _out.dec();
        _out.dec();

        _out << sp << nl << "def __ne__(self, other):";
        _out.inc();
        _out << nl << "r = self.__compare(other)";
        _out << nl << "if r is NotImplemented:";
        _out.inc();
        _out << nl << "return r";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        _out << nl << "return r != 0";
        _out.dec();
        _out.dec();
    }
    else
    {
        //
        // Only generate the rich equality operators __eq__ and __ne__.
        //

        _out << sp << nl << "def __eq__(self, other):";
        _out.inc();
        _out << nl << "if other is None:";
        _out.inc();
        _out << nl << "return False";
        _out.dec();
        _out << nl << "elif not isinstance(other, _M_" << abs << "):";
        _out.inc();
        _out << nl << "return NotImplemented";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        for(MemberInfoList::iterator r = memberList.begin(); r != memberList.end(); ++r)
        {
            //
            // The None value is not orderable in Python 3.
            //
            _out << nl << "if self." << r->fixedName << " != other." << r->fixedName << ':';
            _out.inc();
            _out << nl << "return False";
            _out.dec();
        }
        _out << nl << "return True";
        _out.dec();
        _out.dec();

        _out << sp << nl << "def __ne__(self, other):";
        _out.inc();
        _out << nl << "return not self.__eq__(other)";
        _out.dec();
    }

    //
    // __str__
    //
    _out << sp << nl << "def __str__(self):";
    _out.inc();
    _out << nl << "return IcePy.stringify(self, _M_" << getAbsolute(p, "_t_") << ")";
    _out.dec();
    _out << sp << nl << "__repr__ = __str__";

    _out.dec();

    //
    // Emit the type information.
    //
    _out << sp << nl << "_M_" << getAbsolute(p, "_t_") << " = IcePy.defineStruct('" << scoped << "', " << name << ", ";
    writeMetaData(p->getMetaData());
    _out << ", (";
    //
    // Data members are represented as a tuple:
    //
    //   ('MemberName', MemberMetaData, MemberType)
    //
    // where MemberType is either a primitive type constant (T_INT, etc.) or the id of a constructed type.
    //
    if(memberList.size() > 1)
    {
        _out.inc();
        _out << nl;
    }
    for(MemberInfoList::iterator r = memberList.begin(); r != memberList.end(); ++r)
    {
        if(r != memberList.begin())
        {
            _out << ',' << nl;
        }
        _out << "('" << r->fixedName << "', ";
        writeMetaData(r->dataMember->getMetaData());
        _out << ", ";
        writeType(r->dataMember->type());
        _out << ')';
    }
    if(memberList.size() == 1)
    {
        _out << ',';
    }
    else if(memberList.size() > 1)
    {
        _out.dec();
        _out << nl;
    }
    _out << "))";

    registerName(name);

    _out.dec();

    return false;
}

void
Slice::Python::CodeVisitor::visitSequence(const SequencePtr& p)
{
    static const string protobuf = "python:protobuf:";
    StringList metaData = p->getMetaData();
    bool isCustom = false;
    string customType;
    for(StringList::const_iterator q = metaData.begin(); q != metaData.end(); ++q)
    {
        if(q->find(protobuf) == 0)
        {
            BuiltinPtr builtin = BuiltinPtr::dynamicCast(p->type());
            if(!builtin || builtin->kind() != Builtin::KindByte)
            {
                continue;
            }
            isCustom = true;
            customType = q->substr(protobuf.size());
            break;
        }
    }

    //
    // Emit the type information.
    //
    string scoped = p->scoped();
    _out << sp << nl << "if " << getDictLookup(p, "_t_") << ':';
    _out.inc();
    if(isCustom)
    {
        string package = customType.substr(0, customType.find('.'));
        _out << nl << "import " << package;
        _out << nl << "_M_" << getAbsolute(p, "_t_")
             << " = IcePy.defineCustom('" << scoped << "', " << customType << ")";
    }
    else
    {
        _out << nl << "_M_" << getAbsolute(p, "_t_") << " = IcePy.defineSequence('" << scoped << "', ";
        writeMetaData(metaData);
        _out << ", ";
        writeType(p->type());
        _out << ")";
    }
    _out.dec();
}

void
Slice::Python::CodeVisitor::visitDictionary(const DictionaryPtr& p)
{
    //
    // Emit the type information.
    //
    string scoped = p->scoped();
    _out << sp << nl << "if " << getDictLookup(p, "_t_") << ':';
    _out.inc();
    _out << nl << "_M_" << getAbsolute(p, "_t_") << " = IcePy.defineDictionary('" << scoped << "', ";
    writeMetaData(p->getMetaData());
    _out << ", ";
    writeType(p->keyType());
    _out << ", ";
    writeType(p->valueType());
    _out << ")";
    _out.dec();
}

void
Slice::Python::CodeVisitor::visitEnum(const EnumPtr& p)
{
    string scoped = p->scoped();
    string abs = getAbsolute(p);
    string name = fixIdent(p->name());
    EnumeratorList enums = p->enumerators();
    EnumeratorList::iterator q;

    _out << sp << nl << "if " << getDictLookup(p) << ':';
    _out.inc();
    _out << nl << "_M_" << abs << " = Ice.createTempClass()";
    _out << nl << "class " << name << "(Ice.EnumBase):";
    _out.inc();

    writeDocstring(p->comment(), enums);

    _out << sp << nl << "def __init__(self, _n, _v):";
    _out.inc();
    _out << nl << "Ice.EnumBase.__init__(self, _n, _v)";
    _out.dec();

    _out << sp << nl << "def valueOf(self, _n):";
    _out.inc();
    _out << nl << "if _n in self._enumerators:";
    _out.inc();
    _out << nl << "return self._enumerators[_n]";
    _out.dec();
    _out << nl << "return None";
    _out.dec();
    _out << nl << "valueOf = classmethod(valueOf)";

    _out.dec();

    _out << sp;
    for(q = enums.begin(); q != enums.end(); ++q)
    {
        string fixedEnum = fixIdent((*q)->name());
        _out << nl << name << '.' << fixedEnum << " = " << name << "(\"" << (*q)->name() << "\", " << (*q)->value()
             << ')';
    }
    _out << nl << name << "._enumerators = { ";
    for(q = enums.begin(); q != enums.end(); ++q)
    {
        if(q != enums.begin())
        {
            _out << ", ";
        }
        string fixedEnum = fixIdent((*q)->name());
        _out << (*q)->value() << ':' << name << '.' << fixedEnum;
    }
    _out << " }";

    //
    // Emit the type information.
    //
    _out << sp << nl << "_M_" << getAbsolute(p, "_t_") << " = IcePy.defineEnum('" << scoped << "', " << name
         << ", ";
    writeMetaData(p->getMetaData());
    _out << ", " << name << "._enumerators)";

    registerName(name);

    _out.dec();
}

void
Slice::Python::CodeVisitor::visitConst(const ConstPtr& p)
{
    Slice::TypePtr type = p->type();
    string name = fixIdent(p->name());

    _out << sp << nl << "_M_" << getAbsolute(p) << " = ";
    writeConstantValue(type, p->valueType(), p->value());
}

string
Slice::Python::CodeVisitor::getSymbol(const ContainedPtr& p, const string& prefix, const string& suffix)
{
    //
    // An explicit reference to another type must always be prefixed with "_M_".
    //
    return "_M_" + getAbsolute(p, prefix, suffix);
}

void
Slice::Python::CodeVisitor::registerName(const string& name)
{
    assert(!_moduleStack.empty());
    _out << sp << nl << "_M_" << _moduleStack.front() << '.' << name << " = " << name;
    _out << nl << "del " << name;
}

void
Slice::Python::CodeVisitor::writeType(const TypePtr& p)
{
    BuiltinPtr builtin = BuiltinPtr::dynamicCast(p);
    if(builtin)
    {
        switch(builtin->kind())
        {
            case Builtin::KindBool:
            {
                _out << "IcePy._t_bool";
                break;
            }
            case Builtin::KindByte:
            {
                _out << "IcePy._t_byte";
                break;
            }
            case Builtin::KindShort:
            {
                _out << "IcePy._t_short";
                break;
            }
            case Builtin::KindInt:
            {
                _out << "IcePy._t_int";
                break;
            }
            case Builtin::KindLong:
            {
                _out << "IcePy._t_long";
                break;
            }
            case Builtin::KindFloat:
            {
                _out << "IcePy._t_float";
                break;
            }
            case Builtin::KindDouble:
            {
                _out << "IcePy._t_double";
                break;
            }
            case Builtin::KindString:
            {
                _out << "IcePy._t_string";
                break;
            }
            case Builtin::KindObject:
            case Builtin::KindValue:
            {
                _out << "IcePy._t_Value";
                break;
            }
            case Builtin::KindObjectProxy:
            {
                _out << "IcePy._t_ObjectPrx";
                break;
            }
            case Builtin::KindLocalObject:
            {
                _out << "IcePy._t_LocalObject";
                break;
            }
        }
        return;
    }

    ProxyPtr prx = ProxyPtr::dynamicCast(p);
    if(prx)
    {
        ClassDefPtr def = prx->_class()->definition();
        if(!def || def->isAbstract())
        {
            _out << "_M_" << getAbsolute(prx->_class(), "_t_", "Prx");
        }
        else
        {
            _out << "IcePy._t_ObjectPrx";
        }
        return;
    }

    ContainedPtr cont = ContainedPtr::dynamicCast(p);
    assert(cont);
    _out << "_M_" << getAbsolute(cont, "_t_");
}

void
Slice::Python::CodeVisitor::writeInitializer(const DataMemberPtr& m)
{
    TypePtr p = m->type();
    BuiltinPtr builtin = BuiltinPtr::dynamicCast(p);
    if(builtin)
    {
        switch(builtin->kind())
        {
            case Builtin::KindBool:
            {
                _out << "False";
                break;
            }
            case Builtin::KindByte:
            case Builtin::KindShort:
            case Builtin::KindInt:
            case Builtin::KindLong:
            {
                _out << "0";
                break;
            }
            case Builtin::KindFloat:
            case Builtin::KindDouble:
            {
                _out << "0.0";
                break;
            }
            case Builtin::KindString:
            {
                _out << "''";
                break;
            }
            case Builtin::KindValue:
            case Builtin::KindObject:
            case Builtin::KindObjectProxy:
            case Builtin::KindLocalObject:
            {
                _out << "None";
                break;
            }
        }
        return;
    }

    EnumPtr en = EnumPtr::dynamicCast(p);
    if(en)
    {
        EnumeratorList enums = en->enumerators();
        _out << getSymbol(en) << "." << fixIdent(enums.front()->name());
        return;
    }

    StructPtr st = StructPtr::dynamicCast(p);
    if(st)
    {
        //
        // We cannot emit a call to the struct's constructor here because Python
        // only evaluates this expression once (see bug 3676). Instead, we emit
        // a marker that allows us to determine whether the application has
        // supplied a value.
        //
        _out << "Ice._struct_marker";
        return;
    }

    _out << "None";
}

void
Slice::Python::CodeVisitor::writeHash(const string& name, const TypePtr& p, int& iter)
{
    SequencePtr seq = SequencePtr::dynamicCast(p);
    if(seq)
    {
        _out << nl << "if " << name << ':';
        _out.inc();
        _out << nl << "for _i" << iter << " in " << name << ':';
        _out.inc();
        ostringstream elem;
        elem << "_i" << iter;
        iter++;
        writeHash(elem.str(), seq->type(), iter);
        _out.dec();
        _out.dec();
        return;
    }

    DictionaryPtr dict = DictionaryPtr::dynamicCast(p);
    if(dict)
    {
        _out << nl << "if " << name << ':';
        _out.inc();
        _out << nl << "for _i" << iter << " in " << name << ':';
        _out.inc();
        ostringstream key;
        key << "_i" << iter;
        ostringstream value;
        value << name << '[' << key.str() << ']';
        iter++;
        writeHash(key.str(), dict->keyType(), iter);
        writeHash(value.str(), dict->valueType(), iter);
        _out.dec();
        _out.dec();
        return;
    }

    _out << nl << "_h = 5 * _h + Ice.getHash(" << name << ")";
}

void
Slice::Python::CodeVisitor::writeMetaData(const StringList& meta)
{
    int i = 0;
    _out << '(';
    for(StringList::const_iterator p = meta.begin(); p != meta.end(); ++p)
    {
        if(p->find("python:") == 0)
        {
            if(i > 0)
            {
                _out << ", ";
            }
            _out << "'" << *p << "'";
            ++i;
        }
    }
    if(i == 1)
    {
        _out << ',';
    }
    _out << ')';
}

void
Slice::Python::CodeVisitor::writeAssign(const MemberInfo& info)
{
    string paramName = info.fixedName;
    string memberName = info.fixedName;

    //
    // Structures are treated differently (see bug 3676).
    //
    StructPtr st = StructPtr::dynamicCast(info.dataMember->type());
    if(st && !info.dataMember->optional())
    {
        _out << nl << "if " << paramName << " is Ice._struct_marker:";
        _out.inc();
        _out << nl << "self." << memberName << " = " << getSymbol(st) << "()";
        _out.dec();
        _out << nl << "else:";
        _out.inc();
        _out << nl << "self." << memberName << " = " << paramName;
        _out.dec();
    }
    else
    {
        _out << nl << "self." << memberName << " = " << paramName;
    }
}

void
Slice::Python::CodeVisitor::writeConstantValue(const TypePtr& type, const SyntaxTreeBasePtr& valueType,
                                               const string& value)
{
    ConstPtr constant = ConstPtr::dynamicCast(valueType);
    if(constant)
    {
        _out << "_M_" << getAbsolute(constant);
    }
    else
    {
        Slice::BuiltinPtr b = Slice::BuiltinPtr::dynamicCast(type);
        Slice::EnumPtr en = Slice::EnumPtr::dynamicCast(type);
        if(b)
        {
            switch(b->kind())
            {
            case Slice::Builtin::KindBool:
            {
                _out << (value == "true" ? "True" : "False");
                break;
            }
            case Slice::Builtin::KindByte:
            case Slice::Builtin::KindShort:
            case Slice::Builtin::KindInt:
            case Slice::Builtin::KindFloat:
            case Slice::Builtin::KindDouble:
            case Slice::Builtin::KindLong:
            {
                _out << value;
                break;
            }
            case Slice::Builtin::KindString:
            {
                string sv2 = toStringLiteral(value, "\a\b\f\n\r\t\v", "", Octal, 0);
                string sv3 = toStringLiteral(value, "\a\b\f\n\r\t\v", "", UCN, 0);

                _out << "\"" << sv2<< "\"";
                if(sv2 != sv3)
                {
                    _out << " if _version_info_[0] < 3 else \"" << sv3 << "\"";
                }
                break;
            }
            case Slice::Builtin::KindValue:
            case Slice::Builtin::KindObject:
            case Slice::Builtin::KindObjectProxy:
            case Slice::Builtin::KindLocalObject:
                assert(false);
            }
        }
        else if(en)
        {
            EnumeratorPtr lte = EnumeratorPtr::dynamicCast(valueType);
            assert(lte);
            _out << getSymbol(lte);
        }
        else
        {
            assert(false); // Unknown const type.
        }
    }
}

void
Slice::Python::CodeVisitor::writeConstructorParams(const MemberInfoList& members)
{
    for(MemberInfoList::const_iterator p = members.begin(); p != members.end(); ++p)
    {
        _out << ", " << p->fixedName << "=";

        const DataMemberPtr member = p->dataMember;
        if(member->defaultValueType())
        {
            writeConstantValue(member->type(), member->defaultValueType(), member->defaultValue());
        }
        else if(member->optional())
        {
            _out << "Ice.Unset";
        }
        else
        {
            writeInitializer(member);
        }
    }
}

string
Slice::Python::CodeVisitor::getOperationMode(Slice::Operation::Mode mode)
{
    string result;
    switch(mode)
    {
    case Operation::Normal:
        result = "Ice.OperationMode.Normal";
        break;
    case Operation::Nonmutating:
        result = "Ice.OperationMode.Nonmutating";
        break;
    case Operation::Idempotent:
        result = "Ice.OperationMode.Idempotent";
        break;
    }
    return result;
}

void
Slice::Python::CodeVisitor::collectClassMembers(const ClassDefPtr& p, MemberInfoList& allMembers, bool inherited)
{
    ClassList bases = p->bases();
    if(!bases.empty() && !bases.front()->isInterface())
    {
        collectClassMembers(bases.front(), allMembers, true);
    }

    DataMemberList members = p->dataMembers();

    for(DataMemberList::iterator q = members.begin(); q != members.end(); ++q)
    {
        MemberInfo m;
        if(p->hasMetaData("protected") || (*q)->hasMetaData("protected"))
        {
            m.fixedName = "_" + fixIdent((*q)->name());
        }
        else
        {
            m.fixedName = fixIdent((*q)->name());
        }
        m.inherited = inherited;
        m.dataMember = *q;
        allMembers.push_back(m);
    }
}

void
Slice::Python::CodeVisitor::collectExceptionMembers(const ExceptionPtr& p, MemberInfoList& allMembers, bool inherited)
{
    ExceptionPtr base = p->base();
    if(base)
    {
        collectExceptionMembers(base, allMembers, true);
    }

    DataMemberList members = p->dataMembers();

    for(DataMemberList::iterator q = members.begin(); q != members.end(); ++q)
    {
        MemberInfo m;
        m.fixedName = fixIdent((*q)->name());
        m.inherited = inherited;
        m.dataMember = *q;
        allMembers.push_back(m);
    }
}

Slice::Python::CodeVisitor::StringVec
Slice::Python::CodeVisitor::stripMarkup(const string& comment)
{
    //
    // Strip HTML markup and javadoc links.
    //
    string text = comment;
    string::size_type pos = 0;
    do
    {
        pos = text.find('<', pos);
        if(pos != string::npos)
        {
            string::size_type endpos = text.find('>', pos);
            if(endpos == string::npos)
            {
                break;
            }
            text.erase(pos, endpos - pos + 1);
        }
    } while(pos != string::npos);

    const string link = "{@link";
    pos = 0;
    do
    {
        pos = text.find(link, pos);
        if(pos != string::npos)
        {
            text.erase(pos, link.size());
            string::size_type endpos = text.find('}', pos);
            if(endpos != string::npos)
            {
                string::size_type identpos = text.find_first_not_of(" \t#", pos);
                if(identpos != string::npos && identpos < endpos)
                {
                    string ident = text.substr(identpos, endpos - identpos);
                    text.replace(pos, endpos - pos + 1, fixIdent(ident));
                }
            }
        }
    } while(pos != string::npos);

    //
    // Strip @see sections.
    //
    static const string seeTag = "@see";
    pos = 0;
    do
    {
        //
        // Look for the next @ and delete up to that, or
        // to the end of the string, if not found.
        //
        pos = text.find(seeTag, pos);
        if(pos != string::npos)
        {
            string::size_type next = text.find('@', pos + seeTag.size());
            if(next != string::npos)
            {
                text.erase(pos, next - pos);
            }
            else
            {
                text.erase(pos, string::npos);
            }
        }
    } while(pos != string::npos);

    //
    // Escape triple quotes.
    //
    static const string singleQuotes = "'''";
    pos = 0;
    while((pos = text.find(singleQuotes, pos)) != string::npos)
    {
        text.insert(pos, "\\");
        pos += singleQuotes.size() + 1;
    }
    static const string doubleQuotes = "\"\"\"";
    pos = 0;
    while((pos = text.find(doubleQuotes, pos)) != string::npos)
    {
        text.insert(pos, "\\");
        pos += doubleQuotes.size() + 1;
    }

    //
    // Fold multiple empty lines.
    //
    pos = 0;
    while(true)
    {
        pos = text.find('\n', pos);
        if(pos == string::npos)
        {
            break;
        }

        //
        // Skip the next LF or CR/LF, if present.
        //
        if(pos < text.size() - 1 && text[pos + 1] == '\n')
        {
            pos += 2;
        }
        else if(pos < text.size() - 2 && text[pos + 1] == '\r' && text[pos + 2] == '\n')
        {
            pos += 3;
        }
        else
        {
            ++pos;
            continue;
        }

        //
        // Erase any more CR/LF characters.
        //
        string::size_type next = text.find_first_not_of("\r\n", pos);
        if(next != string::npos)
        {
            text.erase(pos, next - pos);
        }
    }

    //
    // Remove trailing whitespace.
    //
    pos = text.find_last_not_of(" \t\r\n");
    if(pos != string::npos)
    {
        text.erase(pos + 1, text.size() - pos - 1);
    }

    //
    // Split text into lines.
    //
    StringVec lines;
    if(!text.empty())
    {
        string::size_type start = 0;
        while(start != string::npos)
        {
            string::size_type newline = text.find_first_of("\r\n", start);
            string line;
            if(newline != string::npos)
            {
                line = text.substr(start, newline - start);
                start = newline;
            }
            else
            {
                line = text.substr(start);
                start = text.size();
            }

            //
            // Remove trailing whitespace
            //
            pos = line.find_last_not_of(" \t");
            if(pos != string::npos)
            {
                line.erase(pos + 1, line.size() - pos - 1);
            }

            lines.push_back(line);

            start = text.find_first_not_of("\r\n", start);
        }
    }

    return lines;
}

void
Slice::Python::CodeVisitor::writeDocstring(const string& comment, const string& prefix)
{
    StringVec lines = stripMarkup(comment);
    if(lines.empty())
    {
        return;
    }

    _out << nl << prefix << "\"\"\"";

    for(StringVec::const_iterator q = lines.begin(); q != lines.end(); ++q)
    {
        _out << nl << *q;
    }

    _out << nl << "\"\"\"";
}

void
Slice::Python::CodeVisitor::writeDocstring(const string& comment, const DataMemberList& members)
{
    StringVec lines = stripMarkup(comment);
    if(lines.empty())
    {
        return;
    }

    _out << nl << "\"\"\"";

    for(StringVec::const_iterator q = lines.begin(); q != lines.end(); ++q)
    {
        _out << nl << *q;
    }

    if(!members.empty())
    {
        //
        // Collect docstrings (if any) for the members.
        //
        map<string, StringVec> docs;
        for(DataMemberList::const_iterator m = members.begin(); m != members.end(); ++m)
        {
            StringVec doc = stripMarkup((*m)->comment());
            if(!doc.empty())
            {
                docs[(*m)->name()] = doc;
            }
        }
        //
        // Only emit members if there's a docstring for at least one member.
        //
        if(!docs.empty())
        {
            _out << nl << "Members:";
            for(DataMemberList::const_iterator m = members.begin(); m != members.end(); ++m)
            {
                _out << nl << fixIdent((*m)->name()) << " -- ";
                map<string, StringVec>::iterator p = docs.find((*m)->name());
                if(p != docs.end())
                {
                    for(StringVec::const_iterator q = p->second.begin(); q != p->second.end(); ++q)
                    {
                        if(q != p->second.begin())
                        {
                            _out << nl;
                        }
                        _out << *q;
                    }
                }
            }
        }
    }

    _out << nl << "\"\"\"";
}

void
Slice::Python::CodeVisitor::writeDocstring(const string& comment, const EnumeratorList& enums)
{
    StringVec lines = stripMarkup(comment);
    if(lines.empty())
    {
        return;
    }

    _out << nl << "\"\"\"";

    for(StringVec::const_iterator q = lines.begin(); q != lines.end(); ++q)
    {
        _out << nl << *q;
    }

    if(!enums.empty())
    {
        //
        // Collect docstrings (if any) for the enumerators.
        //
        map<string, StringVec> docs;
        for(EnumeratorList::const_iterator e = enums.begin(); e != enums.end(); ++e)
        {
            StringVec doc = stripMarkup((*e)->comment());
            if(!doc.empty())
            {
                docs[(*e)->name()] = doc;
            }
        }
        //
        // Only emit enumerators if there's a docstring for at least one enumerator.
        //
        if(!docs.empty())
        {
            _out << nl << "Enumerators:";
            for(EnumeratorList::const_iterator e = enums.begin(); e != enums.end(); ++e)
            {
                _out << nl << fixIdent((*e)->name()) << " -- ";
                map<string, StringVec>::iterator p = docs.find((*e)->name());
                if(p != docs.end())
                {
                    for(StringVec::const_iterator q = p->second.begin(); q != p->second.end(); ++q)
                    {
                        if(q != p->second.begin())
                        {
                            _out << nl;
                        }
                        _out << *q;
                    }
                }
            }
        }
    }

    _out << nl << "\"\"\"";
}

bool
Slice::Python::CodeVisitor::parseOpComment(const string& comment, OpComment& c)
{
    //
    // Remove most javadoc & HTML markup.
    //
    StringVec lines = stripMarkup(comment);
    if(lines.empty())
    {
        return false;
    }

    //
    // Extract the descriptions of parameters, exceptions and return values.
    //
    string name;
    bool inParam = false, inException = false, inReturn = false;
    vector<string>::iterator i = lines.begin();
    while(i != lines.end())
    {
        string l = *i;
        string::size_type paramTag = l.find("@param");
        string::size_type throwTag = l.find("@throw");
        string::size_type returnTag = l.find("@return");

        if(paramTag != string::npos)
        {
            string::size_type pos = l.find_first_of(" \t", paramTag);
            if(pos != string::npos)
            {
                pos = l.find_first_not_of(" \t", pos);
            }
            if(pos != string::npos)
            {
                string::size_type namePos = pos;
                pos = l.find_first_of(" \t", pos);
                inParam = true;
                inException = false;
                inReturn = false;
                if(pos == string::npos)
                {
                    //
                    // Doc assumed to have the format
                    //
                    // @param foo
                    // Description of foo...
                    //
                    name = l.substr(namePos);
                    c.params[name] = "";
                }
                else
                {
                    name = l.substr(namePos, pos - namePos);
                    pos = l.find_first_not_of(" \t", pos);
                    if(pos != string::npos)
                    {
                        c.params[name] = l.substr(pos);
                    }
                    else
                    {
                        c.params[name] = "";
                    }
                }
            }
            i = lines.erase(i);
            continue;
        }
        else if(throwTag != string::npos)
        {
            string::size_type pos = l.find_first_of(" \t", throwTag);
            if(pos != string::npos)
            {
                pos = l.find_first_not_of(" \t", pos);
            }
            if(pos != string::npos)
            {
                string::size_type namePos = pos;
                pos = l.find_first_of(" \t", pos);
                inException = true;
                inParam = false;
                inReturn = false;
                if(pos == string::npos)
                {
                    //
                    // Doc assumed to have the format
                    //
                    // @throw foo
                    // Description of foo...
                    //
                    name = l.substr(namePos);
                    c.exceptions[name] = "";
                }
                else
                {
                    name = l.substr(namePos, pos - namePos);
                    pos = l.find_first_not_of(" \t", pos);
                    if(pos != string::npos)
                    {
                        c.exceptions[name] = l.substr(pos);
                    }
                    else
                    {
                        c.exceptions[name] = "";
                    }
                }
            }
            i = lines.erase(i);
            continue;
        }
        else if(returnTag != string::npos)
        {
            string::size_type pos = l.find_first_of(" \t", returnTag);
            if(pos != string::npos)
            {
                pos = l.find_first_not_of(" \t", pos);
            }
            if(pos != string::npos)
            {
                inReturn = true;
                inException = false;
                inParam = false;
                c.returns = l.substr(pos);
            }
            i = lines.erase(i);
            continue;
        }
        else
        {
            //
            // We didn't find a tag so we assume this line is a continuation of a
            // previous description.
            //
            string::size_type pos = l.find_first_not_of(" \t");
            if(pos != string::npos && l[pos] != '@')
            {
                if(inParam)
                {
                    assert(!name.empty());
                    if(!c.params[name].empty())
                    {
                        c.params[name] += " ";
                    }
                    c.params[name] += l.substr(pos);
                    i = lines.erase(i);
                    continue;
                }
                else if(inException)
                {
                    assert(!name.empty());
                    if(!c.exceptions[name].empty())
                    {
                        c.exceptions[name] += " ";
                    }
                    c.exceptions[name] += l.substr(pos);
                    i = lines.erase(i);
                    continue;
                }
                else if(inReturn)
                {
                    if(!c.returns.empty())
                    {
                        c.returns += " ";
                    }
                    c.returns += l.substr(pos);
                    i = lines.erase(i);
                    continue;
                }
            }
        }

        i++;
    }

    //
    // All remaining lines become the general description.
    //
    for(vector<string>::iterator p = lines.begin(); p != lines.end(); ++p)
    {
        if(p->find_first_not_of(" \t\n\r") != string::npos)
        {
            c.description.push_back(*p);
        }
    }

    return true;
}

void
Slice::Python::CodeVisitor::writeDocstring(const OperationPtr& op, DocstringMode mode, bool local)
{
    OpComment comment;
    if(!parseOpComment(op->comment(), comment))
    {
        return;
    }

    TypePtr ret = op->returnType();
    ParamDeclList params = op->parameters();
    vector<string> inParams, outParams;
    for(ParamDeclList::iterator p = params.begin(); p != params.end(); ++p)
    {
        if((*p)->isOutParam())
        {
            outParams.push_back((*p)->name());
        }
        else
        {
            inParams.push_back((*p)->name());
        }
    }

    if(comment.description.empty())
    {
        if((mode == DocSync || mode == DocDispatch) && comment.params.empty() && comment.exceptions.empty() &&
           comment.returns.empty())
        {
            return;
        }
        else if((mode == DocAsync || mode == DocAsyncBegin) && inParams.empty())
        {
            return;
        }
        else if(mode == DocAsyncEnd && outParams.empty() && comment.returns.empty())
        {
            return;
        }
        else if(mode == DocAsyncDispatch && inParams.empty() && comment.exceptions.empty())
        {
            return;
        }
    }

    //
    // Emit the general description.
    //
    _out << nl << "\"\"\"";
    if(!comment.description.empty())
    {
        for(StringVec::const_iterator q = comment.description.begin(); q != comment.description.end(); ++q)
        {
            _out << nl << *q;
        }
    }

    //
    // Emit arguments.
    //
    bool needArgs = false;
    switch(mode)
    {
    case DocSync:
    case DocAsync:
    case DocAsyncBegin:
    case DocDispatch:
        needArgs = !local || !inParams.empty();
        break;
    case DocAsyncEnd:
    case DocAsyncDispatch:
        needArgs = true;
        break;
    }

    if(needArgs)
    {
        _out << nl << "Arguments:";
        for(vector<string>::iterator q = inParams.begin(); q != inParams.end(); ++q)
        {
            string fixed = fixIdent(*q);
            _out << nl << fixed << " -- ";
            StringMap::const_iterator r = comment.params.find(*q);
            if(r == comment.params.end())
            {
                r = comment.params.find(fixed); // Just in case.
            }
            if(r != comment.params.end())
            {
                _out << r->second;
            }
        }
        if(mode == DocAsyncBegin)
        {
            _out << nl << "_response -- The asynchronous response callback."
                 << nl << "_ex -- The asynchronous exception callback."
                 << nl << "_sent -- The asynchronous sent callback.";
        }
        if(!local && (mode == DocSync || mode == DocAsync || mode == DocAsyncBegin))
        {
             const string contextParamName = getEscapedParamName(op, "context");
            _out << nl << contextParamName << " -- The request context for the invocation.";
        }
        if(!local && (mode == DocDispatch || mode == DocAsyncDispatch))
        {
            const string currentParamName = getEscapedParamName(op, "current");
            _out << nl << currentParamName << " -- The Current object for the invocation.";
        }
    }
    else if(mode == DocAsyncEnd)
    {
        _out << nl << "Arguments:"
             << nl << "_r - The asynchronous result object for the invocation.";
    }

    //
    // Emit return value(s).
    //
    if(mode == DocAsync || mode == DocAsyncDispatch)
    {
        _out << nl << "Returns: A future object for the invocation.";
    }
    if(mode == DocAsyncBegin)
    {
        _out << nl << "Returns: An asynchronous result object for the invocation.";
    }

    if((mode == DocSync || mode == DocAsyncEnd || mode == DocDispatch) && (ret || !outParams.empty()))
    {
        if((outParams.size() + (ret ? 1 : 0)) > 1)
        {
            _out << nl << "Returns a tuple containing the following:";
            if(ret)
            {
                _out << nl << "_retval -- " << comment.returns;
            }
            for(vector<string>::iterator q = outParams.begin(); q != outParams.end(); ++q)
            {
                string fixed = fixIdent(*q);
                _out << nl << fixed << " -- ";
                StringMap::const_iterator r = comment.params.find(*q);
                if(r == comment.params.end())
                {
                    r = comment.params.find(fixed); // Just in case.
                }
                if(r != comment.params.end())
                {
                    _out << r->second;
                }
            }
        }
        else if(ret && !comment.returns.empty())
        {
            _out << nl << "Returns: " << comment.returns;
        }
        else if(!outParams.empty())
        {
            assert(outParams.size() == 1);
            _out << nl << "Returns:";
            string fixed = fixIdent(outParams[0]);
            _out << nl << fixed << " -- ";
            StringMap::const_iterator r = comment.params.find(outParams[0]);
            if(r == comment.params.end())
            {
                r = comment.params.find(fixed); // Just in case.
            }
            if(r != comment.params.end())
            {
                _out << r->second;
            }
        }
    }

    //
    // Emit exceptions.
    //
    if((mode == DocSync || mode == DocAsyncEnd || mode == DocDispatch || mode == DocAsyncDispatch) &&
       !comment.exceptions.empty())
    {
        _out << nl << "Throws:";
        for(StringMap::const_iterator r = comment.exceptions.begin(); r != comment.exceptions.end(); ++r)
        {
            _out << nl << r->first << " -- " << r->second;
        }
    }
    _out << nl << "\"\"\"";
}

string
Slice::Python::getPackageDirectory(const string& file, const UnitPtr& ut)
{
    //
    // file must be a fully-qualified path name.
    //

    //
    // Check if the file contains the python:pkgdir file metadata.
    //
    DefinitionContextPtr dc = ut->findDefinitionContext(file);
    assert(dc);
    const string prefix = "python:pkgdir:";
    string pkgdir = dc->findMetaData(prefix);
    if(!pkgdir.empty())
    {
        //
        // The metadata is present, so the generated file was placed in the specified directory.
        //
        pkgdir = pkgdir.substr(prefix.size());
        assert(!pkgdir.empty()); // This situation should have been caught by MetaDataVisitor.
    }
    return pkgdir;
}

string
Slice::Python::getImportFileName(const string& file, const UnitPtr& ut, const vector<string>& includePaths)
{
    //
    // The file and includePaths arguments must be fully-qualified path names.
    //

    //
    // Check if the file contains the python:pkgdir file metadata.
    //
    string pkgdir = getPackageDirectory(file, ut);
    if(!pkgdir.empty())
    {
        //
        // The metadata is present, so the generated file was placed in the specified directory.
        //
        vector<string> names;
        IceUtilInternal::splitString(pkgdir, "/", names);
        assert(!names.empty());
        pkgdir = "";
        for(vector<string>::iterator p = names.begin(); p != names.end(); ++p)
        {
            if(p != names.begin())
            {
                pkgdir += ".";
            }
            pkgdir += fixIdent(*p);
        }
        string::size_type pos = file.rfind('/');
        assert(pos != string::npos);
        string name = file.substr(pos + 1); // Get the name of the file without the leading path.
        assert(!name.empty());
        replace(name.begin(), name.end(), '.', '_'); // Convert .ice to _ice
        return pkgdir + "." + name;
    }
    else
    {
        //
        // The metadata is not present, so we transform the file name using the include paths (-I)
        // given to the compiler.
        //
        string name = changeInclude(file, includePaths);
        replace(name.begin(), name.end(), '/', '_');
        return name + "_ice";
    }
}

void
Slice::Python::generate(const UnitPtr& un, bool all, bool checksum, const vector<string>& includePaths,
                        Output& out)
{
    Slice::Python::MetaDataVisitor visitor;
    un->visit(&visitor, false);

    out << nl << "from sys import version_info as _version_info_";
    out << nl << "import Ice, IcePy";

    if(!all)
    {
        vector<string> paths = includePaths;
        for(vector<string>::iterator p = paths.begin(); p != paths.end(); ++p)
        {
            *p = fullPath(*p);
        }

        StringList includes = un->includeFiles();
        for(StringList::const_iterator q = includes.begin(); q != includes.end(); ++q)
        {
            out << nl << "import " << getImportFileName(*q, un, paths);
        }
    }

    set<string> moduleHistory;

    ModuleVisitor moduleVisitor(out, moduleHistory);
    un->visit(&moduleVisitor, true);

    CodeVisitor codeVisitor(out, moduleHistory);
    un->visit(&codeVisitor, false);

    if(checksum)
    {
        ChecksumMap checksums = createChecksums(un);
        if(!checksums.empty())
        {
            out << sp;
            for(ChecksumMap::const_iterator p = checksums.begin(); p != checksums.end(); ++p)
            {
                out << nl << "Ice.sliceChecksums[\"" << p->first << "\"] = \"";
                ostringstream str;
                str.flags(ios_base::hex);
                str.fill('0');
                for(vector<unsigned char>::const_iterator q = p->second.begin(); q != p->second.end(); ++q)
                {
                    str << static_cast<int>(*q);
                }
                out << str.str() << "\"";
            }
        }
    }

    out << nl; // Trailing newline.
}

string
Slice::Python::scopedToName(const string& scoped)
{
    string result = fixIdent(scoped);
    if(result.find("::") == 0)
    {
        result.erase(0, 2);
    }

    string::size_type pos;
    while((pos = result.find("::")) != string::npos)
    {
        result.replace(pos, 2, ".");
    }

    return result;
}

string
Slice::Python::fixIdent(const string& ident)
{
    if(ident[0] != ':')
    {
        return lookupKwd(ident);
    }
    vector<string> ids = splitScopedName(ident);
    transform(ids.begin(), ids.end(), ids.begin(), ptr_fun(lookupKwd));
    stringstream result;
    for(vector<string>::const_iterator i = ids.begin(); i != ids.end(); ++i)
    {
        result << "::" + *i;
    }
    return result.str();
}

string
Slice::Python::getPackageMetadata(const ContainedPtr& cont)
{
    //
    // Traverse to the top-level module.
    //
    ModulePtr m;
    ContainedPtr p = cont;
    while(true)
    {
        if(ModulePtr::dynamicCast(p))
        {
            m = ModulePtr::dynamicCast(p);
        }

        ContainerPtr c = p->container();
        p = ContainedPtr::dynamicCast(c); // This cast fails for Unit.
        if(!p)
        {
            break;
        }
    }

    assert(m);

    //
    // The python:package metadata can be defined as file metadata or applied to a top-level module.
    // We check for the metadata at the top-level module first and then fall back to the global scope.
    //
    static const string prefix = "python:package:";

    string q;
    if(!m->findMetaData(prefix, q))
    {
        UnitPtr ut = cont->unit();
        string file = cont->file();
        assert(!file.empty());

        DefinitionContextPtr dc = ut->findDefinitionContext(file);
        assert(dc);
        q = dc->findMetaData(prefix);
    }

    if(!q.empty())
    {
        q = q.substr(prefix.size());
    }

    return q;
}

string
Slice::Python::getAbsolute(const ContainedPtr& cont, const string& suffix, const string& nameSuffix)
{
    string scope = scopedToName(cont->scope());

    string package = getPackageMetadata(cont);
    if(!package.empty())
    {
        if(!scope.empty())
        {
            scope = package + "." + scope;
        }
        else
        {
            scope = package + ".";
        }
    }

    return scope + suffix + fixIdent(cont->name() + nameSuffix);
}

void
Slice::Python::printHeader(IceUtilInternal::Output& out)
{
    static const char* header =
"#\n"
"# Copyright (c) ZeroC, Inc. All rights reserved.\n"
"#\n"
        ;

    out << header;
    out << "#\n";
    out << "# Ice version " << ICE_STRING_VERSION << "\n";
    out << "#\n";
}

bool
Slice::Python::MetaDataVisitor::visitUnitStart(const UnitPtr& p)
{
    static const string prefix = "python:";

    //
    // Validate file metadata in the top-level file and all included files.
    //
    StringList files = p->allFiles();
    for(StringList::iterator q = files.begin(); q != files.end(); ++q)
    {
        string file = *q;
        DefinitionContextPtr dc = p->findDefinitionContext(file);
        assert(dc);
        StringList globalMetaData = dc->getMetaData();
        for(StringList::const_iterator r = globalMetaData.begin(); r != globalMetaData.end();)
        {
            string s = *r++;
            if(s.find(prefix) == 0)
            {
                static const string packagePrefix = "python:package:";
                if(s.find(packagePrefix) == 0 && s.size() > packagePrefix.size())
                {
                    continue;
                }
                static const string pkgdirPrefix = "python:pkgdir:";
                if(s.find(pkgdirPrefix) == 0 && s.size() > pkgdirPrefix.size())
                {
                    continue;
                }

                dc->warning(InvalidMetaData, file, "", "ignoring invalid file metadata `" + s + "'");
                globalMetaData.remove(s);
            }
        }
        dc->setMetaData(globalMetaData);
    }
    return true;
}

bool
Slice::Python::MetaDataVisitor::visitModuleStart(const ModulePtr& p)
{
    static const string prefix = "python:package:";

    StringList metaData = p->getMetaData();
    for(StringList::const_iterator r = metaData.begin(); r != metaData.end();)
    {
        string s = *r++;
        if(s.find(prefix) == 0)
        {
            //
            // Must be a top-level module.
            //
            if(UnitPtr::dynamicCast(p->container()))
            {
                continue;
            }
        }

        if(s.find("python:") == 0)
        {
            p->definitionContext()->warning(InvalidMetaData, p->file(), "", "ignoring invalid metadata `" + s + "'");
            metaData.remove(s);
        }
    }

    p->setMetaData(metaData);
    return true;
}

void
Slice::Python::MetaDataVisitor::visitClassDecl(const ClassDeclPtr& p)
{
    reject(p);
}

bool
Slice::Python::MetaDataVisitor::visitClassDefStart(const ClassDefPtr& p)
{
    reject(p);
    return true;
}

bool
Slice::Python::MetaDataVisitor::visitExceptionStart(const ExceptionPtr& p)
{
    reject(p);
    return true;
}

bool
Slice::Python::MetaDataVisitor::visitStructStart(const StructPtr& p)
{
    reject(p);
    return true;
}

void
Slice::Python::MetaDataVisitor::visitOperation(const OperationPtr& p)
{
    TypePtr ret = p->returnType();
    if(ret)
    {
        validateSequence(p->file(), p->line(), ret, p->getMetaData());
    }

    ParamDeclList params = p->parameters();
    for(ParamDeclList::iterator q = params.begin(); q != params.end(); ++q)
    {
        validateSequence(p->file(), (*q)->line(), (*q)->type(), (*q)->getMetaData());
    }
}

void
Slice::Python::MetaDataVisitor::visitDataMember(const DataMemberPtr& p)
{
    validateSequence(p->file(), p->line(), p->type(), p->getMetaData());
}

void
Slice::Python::MetaDataVisitor::visitSequence(const SequencePtr& p)
{
    static const string protobuf = "python:protobuf:";
    StringList metaData = p->getMetaData();
    const string file = p->file();
    const string line = p->line();
    StringList protobufMetaData;
    const UnitPtr ut = p->unit();
    const DefinitionContextPtr dc = ut->findDefinitionContext(file);
    assert(dc);

    for(StringList::const_iterator q = metaData.begin(); q != metaData.end(); )
    {
        string s = *q++;
        if(s.find(protobuf) == 0)
        {
            //
            // Remove from list so validateSequence does not try to handle as well.
            //
            metaData.remove(s);
            BuiltinPtr builtin = BuiltinPtr::dynamicCast(p->type());
            if(!builtin || builtin->kind() != Builtin::KindByte)
            {
                dc->warning(InvalidMetaData, file, line, "ignoring invalid metadata `" + s + ": " +
                            "`protobuf' encoding must be a byte sequence");
            }
            else
            {
                protobufMetaData.push_back(s);
            }
        }
    }

    metaData = validateSequence(file, line, p, metaData);
    metaData.insert(metaData.end(), protobufMetaData.begin(), protobufMetaData.end());
    p->setMetaData(metaData);
}

void
Slice::Python::MetaDataVisitor::visitDictionary(const DictionaryPtr& p)
{
    reject(p);
}

void
Slice::Python::MetaDataVisitor::visitEnum(const EnumPtr& p)
{
    reject(p);
}

void
Slice::Python::MetaDataVisitor::visitConst(const ConstPtr& p)
{
    reject(p);
}

StringList
Slice::Python::MetaDataVisitor::validateSequence(const string& file, const string& line,
                                                 const TypePtr& type, const StringList& metaData)
{
    const UnitPtr ut = type->unit();
    const DefinitionContextPtr dc = ut->findDefinitionContext(file);
    assert(dc);

    static const string prefix = "python:";
    StringList newMetaData = metaData;
    for(StringList::const_iterator p = newMetaData.begin(); p != newMetaData.end();)
    {
        string s = *p++;
        if(s.find(prefix) == 0)
        {
            SequencePtr seq = SequencePtr::dynamicCast(type);
            if(seq)
            {
                static const string seqPrefix = "python:seq:";
                if(s.find(seqPrefix) == 0)
                {
                    string arg = s.substr(seqPrefix.size());
                    if(arg == "tuple" || arg == "list" || arg == "default")
                    {
                        continue;
                    }
                }
                else if(s.size() > prefix.size())
                {
                    string arg = s.substr(prefix.size());
                    if(arg == "tuple" || arg == "list" || arg == "default")
                    {
                        continue;
                    }
                    else if(arg == "array.array" || arg == "numpy.ndarray" || arg.find("memoryview:") == 0)
                    {
                        //
                        // The memoryview sequence metadata is only valid for integral builtin
                        // types excluding strings.
                        //
                        BuiltinPtr builtin = BuiltinPtr::dynamicCast(seq->type());
                        if(builtin)
                        {
                            switch(builtin->kind())
                            {
                            case Builtin::KindBool:
                            case Builtin::KindByte:
                            case Builtin::KindShort:
                            case Builtin::KindInt:
                            case Builtin::KindLong:
                            case Builtin::KindFloat:
                            case Builtin::KindDouble:
                                {
                                    continue;
                                }
                            default:
                                {
                                    break;
                                }
                            }
                        }
                    }
                }
            }
            dc->warning(InvalidMetaData, file, line, "ignoring invalid metadata `" + s + "'");
            newMetaData.remove(s);
        }
    }
    return newMetaData;
}

void
Slice::Python::MetaDataVisitor::reject(const ContainedPtr& cont)
{
    StringList localMetaData = cont->getMetaData();
    static const string prefix = "python:";

    const UnitPtr ut = cont->unit();
    const DefinitionContextPtr dc = ut->findDefinitionContext(cont->file());
    assert(dc);

    for(StringList::const_iterator p = localMetaData.begin(); p != localMetaData.end();)
    {
        string s = *p++;
        if(s.find(prefix) == 0)
        {
            dc->warning(InvalidMetaData, cont->file(), cont->line(), "ignoring invalid metadata `" + s + "'");
            localMetaData.remove(s);
        }
    }
    cont->setMetaData(localMetaData);
}
