racket - scheme' conditional expression and evaluation order -


thinking following expression:

(cond (p1 (some_complex_expression1))       (p2 (some_complex_expression2))       (p3 (some_complex_expression3))       ...       (else (some_complex_expressionn)))

are (some_complex_expressionx)s evaluated on demand? (i.e. '(some_complex_expressionx)' evaluated when predicate before itself, px true) or, follow applicative order(they somehow evaluated as possible before trying predicates)

if implementation-dependent, how following implementations?

mit-scheme guile racket scheme sicp r5rs

the test must return true value before associated expressions evaluated. guaranteed scheme standards; see section 4.2.1 of r5rs, example.


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