MULTIPLE VALUE FUNCTIONS

XLISP-PLUS supports multiple return values (via a compilation option) as in Common Lisp. Note that most FSUBR control structure functions will pass back multiple return values, with the exceptions being PROG1 and PROG2.

BIND RETURN VALUES INTO LOCAL CONTEXT

(multiple-value-bind <varlist> <vform> [<form>...])

defined as macro in common.lsp

<vform> form to be evaluated

<varlist> list of variables to bind to return values of vform

<form> forms evaluated sequentially, as in LET, using local bindings

returns values of last form evaluated, or NIL if no forms

COLLECT VALUES AND APPLY FUNCTION

(multiple-value-call <fun> <form> ...)

fsubr

<fun> function to apply

<form> forms, which are evaluated, with result values collected

returns result of applying fun to all of the returned values of the forms

COLLECT MULTIPLE RETURNED VALUES INTO A LIST

(multiple-value-list <form>)

defined as macro in common.lsp

<form> form to be evaluated

returns list of returned values

RETURN VALUES OF FIRST FORM

(multiple-value-prog1 <form> [<form> ...])

fsubr

<form> one or more forms, which are evaluated sequentially

returns the result values of the first form

BIND RETURN VALUES TO VARIABLES

(multiple-value-setq <varlist> <form>)

defined as macro in common.lsp

<form> form to be evaluated

<varlist> list of variables to bind to return values of form

returns (undefined, implementation dependent)

EXTRACT A RETURN VALUE

(nth-value <index> <form>)

fsubr

<index> index into return values

<form> form which gets evaluated

returns the nth result value of exectuing the form

RETURN MULTIPLE VALUES

(values [<expr>])

<expr> expression(s) to be evaluated

returns each argument as a separate value

RETURN MULTIPLE VALUES FROM LIST

(values-list <list>)

defined in common.lsp

<list> a list

returns each list element as a separate value

XLISP-PLUS - Version 2.1g - Tom Almy tom.almy@tek.com - 18 JUL 94

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