Closures/Value capture: Difference between revisions
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m →{{header|Factor}}: Move a comment. |
→{{header|Factor}}: "Forget the variable!" Add a version that uses fried quotations. |
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=={{header|Factor}}== |
=={{header|Factor}}== |
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===Using lexical variables=== |
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<lang factor>USING: io kernel locals math |
<lang factor>USING: io kernel locals math prettyprint sequences ; |
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[let |
[let |
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! Create a sequence of |
! Create a sequence of 10 quotations |
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10 iota [ |
10 iota [ |
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:> i |
:> i ! Bind lexical variable i |
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[ i i * ] |
[ i i * ] ! Push a quotation to calculate i squared |
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] map :> seq |
] map :> seq |
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The wrong way would use <code>f :> i! 10 iota [ i! [ i i * ] ] map :> seq</code> to mutate a single binding. Then the program would print, "3 squared is 81", "8 squared is 81". |
The wrong way would use <code>f :> i! 10 iota [ i! [ i i * ] ] map :> seq</code> to mutate a single binding. Then the program would print, "3 squared is 81", "8 squared is 81". |
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===Using fried quotations=== |
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Forget the variable! Each ''fried quotation'' captures some values by pulling them from the stack. |
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<lang factor>USING: fry io kernel math prettyprint sequences ; |
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! Push a sequence of 10 quotations |
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10 iota [ |
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'[ _ dup * ] ! Push a quotation ( i -- i*i ) |
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] map |
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{ 3 8 } [ |
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dup pprint " squared is " write |
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over nth call . |
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] each |
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drop</lang> |
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=={{header|Fantom}}== |
=={{header|Fantom}}== |
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