XLISP streamp

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# streamp

Type: | - | predicate function (subr)
Source: | - | xlbfun.c

## Syntax

(streamp expr)
  expr - the expression to check
  returns - T if the value is a stream, NIL otherwise

## Description

The 'streamp' predicate function checks if an 'expr' is a stream. T is returned if 'expr' is a stream, NIL is returned otherwise.

EXAMPLES

    (streamp *standard-input*)             ; returns T - stream
    (streamp *debug-io*)                   ; returns T - stream
    (streamp (make-string-output-stream))  ; returns T - stream

    (setq a *standard-output*)
    (streamp a)                            ; returns T - evaluates to stream

    (streamp "a")                          ; returns NIL - string
    (streamp #\a)                          ; returns NIL - character
    (streamp '(a b c))                     ; returns NIL - list
    (streamp 1)                            ; returns NIL - integer
    (streamp 1.2)                          ; returns NIL - float
    (streamp '*debug-io*)                  ; returns NIL - symbol
    (streamp 'a)                           ; returns NIL - symbol
    (streamp #(0 1 2))                     ; returns NIL - array
    (streamp NIL)                          ; returns NIL - NIL

See the streamp predicate function in the XLISP 2.0 manual.

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Nyquist / XLISP 2.0 - Contents | Tutorials | Examples | Reference