expressions-bindings -- r7rs Category

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Description

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Binding constructs

The binding constructs let, let*, letrec, letrec*, let-values, and let*-values give Scheme a block structure, like Algol 60. The syntax of the first four constructs is identical, but they differ in the regions they establish for their variable bindings. In a let expression, the initial values are computed before any of the variables become bound; in a let* expression, the bindings and evaluations are performed sequentially; while in letrec and letrec* expressions, all the bindings are in effect while their initial values are being computed, thus allowing mutually recursive definitions. The let-values and let*-values constructs are analogous to let and let* respectively, but are designed to handle multiple-valued expressions, binding different identifiers to the returned values.

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

Super-categories

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• expressions;