42 lines
1.7 KiB
Factor
42 lines
1.7 KiB
Factor
USING: help.markup help.syntax slots kernel assocs sequences ;
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IN: mirrors
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ARTICLE: "mirrors" "Mirrors"
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"The " { $vocab-link "mirrors" } " vocabulary defines data types which present an object's slots and slot values as an associative structure. This enables idioms such as iteration over all slots in a tuple, or editing of tuples, sequences and assocs in a generic fashion. This functionality is used by developer tools and meta-programming utilities."
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$nl
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"A mirror provides such a view of a tuple:"
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{ $subsections
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mirror
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<mirror>
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}
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"Utility word used by developer tools which inspect objects:"
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{ $subsections make-mirror }
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{ $see-also "slots" } ;
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ABOUT: "mirrors"
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HELP: mirror
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{ $class-description "An associative structure which wraps an object and presents itself as a mapping from slot names to the object's slot values. Mirrors are used to build reflective developer tools."
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$nl
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"Mirrors are mutable, however new keys cannot be inserted, only values of existing keys can be changed. Deleting a key has the effect of setting its value to " { $link f } "."
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$nl
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"Mirrors are created by calling " { $link <mirror> } " or " { $link make-mirror } "." } ;
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HELP: <mirror>
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{ $values { "object" object } { "mirror" mirror } }
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{ $description "Creates a " { $link mirror } " reflecting an object." }
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{ $examples
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{ $example
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"USING: assocs mirrors prettyprint ;"
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"IN: scratchpad"
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"TUPLE: circle center radius ;"
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"C: <circle> circle"
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"{ 100 50 } 15 <circle> <mirror> >alist ."
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"{ { \"center\" { 100 50 } } { \"radius\" 15 } }"
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}
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} ;
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HELP: make-mirror
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{ $values { "obj" object } { "assoc" assoc } }
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{ $description "Creates an assoc which reflects the internal structure of the object." } ;
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