XLISP tagbody

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# tagbody

Type: | - | special form (fsubr)
Source: | - | xlcont.c

## Syntax

(tagbody [expr ... ])
  expr - expressions comprising the body of the block which may contain gos or tags for go
  returns - NIL

## Description

The 'tagbody' special form is basically a 'block' construct that contains a block of code [expressions] to evaluate. After the execution of the 'tagbody' 'exprs', NIL is returned. The 'tagbody' special form allows 'go-to' style branching within the 'block' construct via the go special form. To allow this, each 'expr' may be a tag or a form. The tag-symbol is the 'label' and must exist somewhere within the 'block' that the go occurs within.

## Examples

    (tagbody                   ; build the 'block'
       start (print "begin")   ; tag - start
             (GO end)
             (print "hello")   ; won't ever be reached
       end   (print "done"))   ; tag - END
                               ; prints  "begin" "done"
                               ; returns NIL

See the tagbody special form in the XLISP 2.0 manual.

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