let-values -- r7rs Definition
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syntax;

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Description
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(let-values <mv-binding-spec> <body>)

Syntax: <Mv-binding-spec> has the form

((<formals_1> <init_1>) ...)

where each <init> is an expression, and <body> is zero or more definitions followed by a sequence of one or more expressions as described in section on lambda. It is an error for a variable to appear more than once in the set of <formals>.

Semantics: The <init>s are evaluated in the current environment (in some unspecified order) as if by invoking call-with-values, and the variables occurring in the <formals> are bound to fresh locations holding the values returned by the <init>s, where the <formals> are matched to the return values in the same way that the <formals> in a lambda expression are matched to the arguments in a procedure call. Then, the <body> is evaluated in the extended environment, and the values of the last expression of <body> are returned. Each binding of a <variable> has <body> as its region.

It is an error if the <formals> do not match the number of values returned by the corresponding <init>.

(let-values (((root rem) (exact-integer-sqrt 32)))
  (* root rem))                ===>  35

The text herein was sourced and adapted as described in the "R7RS attribution of various text snippets" appendix.

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