23 lines
948 B
Factor
23 lines
948 B
Factor
USING: combinators help.markup help.syntax ;
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IN: combinators.extras
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HELP: cond-case
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{ $values { "assoc" "a sequence of quotation pairs and an optional quotation" } }
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{ $description
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"Similar to " { $link case } ", this evaluates an " { $snippet "obj" } " according to the first quotation in each pair. If any quotation returns true, calls the second quotation without " { $snippet "obj" } " on the stack."
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$nl
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"If there is no quotation that returns true, the default case is taken. If the last element of " { $snippet "assoc" } " is a quotation, the quotation is called with " { $snippet "obj" } " on the stack. Otherwise, a " { $link no-cond } " error is raised."
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}
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{ $examples
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{ $example
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"USING: combinators.extras io kernel math ;"
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"0 {"
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" { [ 0 > ] [ \"positive\" ] }"
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" { [ 0 < ] [ \"negative\" ] }"
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" [ drop \"zero\" ]"
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"} cond-case print"
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"zero"
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}
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} ;
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