Find limit of recursion: Difference between revisions
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(→{{header|Applescript}}: Added a basic Applescript version) |
(→{{header|AppleScript}}: Added an alternative test – highest Church numeral representable without stack overflow in Applescript) |
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<pre>"Recursion limit encountered at 502"</pre> |
<pre>"Recursion limit encountered at 502"</pre> |
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We get a fractionally higher (and arguably purer) result by deriving the highest Church Numeral (Church-encoded integer) that can be represented using AppleScript: |
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<lang applescript>-- HIGHEST CHURCH NUMBER REPRESENTABLE IN APPLESCRIPT ? |
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-- (This should be a good proxy for recursion depth) |
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on run |
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script unrepresentable |
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on |λ|(x) |
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try |
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churchFromInt(x) |
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return false |
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on error |
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return true |
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end try |
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x > 10 |
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end |λ| |
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end script |
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"The highest Church-encoded integer representable in Applescript is " & ¬ |
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(|until|(unrepresentable, my succ, 0) - 1) |
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end run |
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-- CHURCH NUMERALS ------------------------------------------------------ |
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-- chZero :: (a -> a) -> a -> a |
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on chZero(f) |
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script |
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on |λ|(x) |
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x |
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end |λ| |
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end script |
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end chZero |
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-- chSucc :: ((a -> a) -> a -> a) -> (a -> a) -> a -> a |
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on chSucc(n) |
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script |
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on |λ|(f) |
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script |
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property mf : mReturn(f)'s |λ| |
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on |λ|(x) |
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mf(mReturn(n)'s |λ|(mf)'s |λ|(x)) |
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end |λ| |
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end script |
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end |λ| |
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end script |
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end chSucc |
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-- churchFromInt :: Int -> (a -> a) -> a -> a |
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on churchFromInt(x) |
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script go |
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on |λ|(i) |
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if 0 < i then |
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chSucc(|λ|(i - 1)) |
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else |
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chZero |
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end if |
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end |λ| |
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end script |
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go's |λ|(x) |
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end churchFromInt |
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-- intFromChurch :: ((Int -> Int) -> Int -> Int) -> Int |
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on intFromChurch(cn) |
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mReturn(cn)'s |λ|(my succ)'s |λ|(0) |
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end intFromChurch |
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-- GENERIC FUNCTIONS ---------------------------------------- |
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-- until :: (a -> Bool) -> (a -> a) -> a -> a |
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on |until|(p, f, x) |
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set v to x |
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set mp to mReturn(p) |
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set mf to mReturn(f) |
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repeat until mp's |λ|(v) |
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set v to mf's |λ|(v) |
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end repeat |
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end |until| |
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-- Lift 2nd class handler function into 1st class script wrapper |
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-- mReturn :: First-class m => (a -> b) -> m (a -> b) |
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on mReturn(f) |
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if class of f is script then |
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f |
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else |
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script |
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property |λ| : f |
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end script |
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end if |
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end mReturn |
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-- succ :: Enum a => a -> a |
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on succ(x) |
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1 + x |
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end succ</lang> |
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{{Out}} |
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<pre>"The highest Church-encoded integer representable in Applescript is 571"</pre> |
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=={{header|AutoHotkey}}== |
=={{header|AutoHotkey}}== |
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