137 lines
3.0 KiB
AppleScript
137 lines
3.0 KiB
AppleScript
-- pascal :: Int -> [[Int]]
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on pascal(intRows)
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script addRow
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on nextRow(row)
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script add
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on lambda(a, b)
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a + b
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end lambda
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end script
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zipWith(add, [0] & row, row & [0])
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end nextRow
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on lambda(xs)
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xs & {nextRow(item -1 of xs)}
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end lambda
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end script
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foldr(addRow, {{1}}, range(1, intRows - 1))
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end pascal
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-- TEST
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on run
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set lstTriangle to pascal(7)
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script spaced
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on lambda(xs)
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script rightAlign
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on lambda(x)
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text -4 thru -1 of (" " & x)
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end lambda
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end script
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intercalate("", map(rightAlign, xs))
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end lambda
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end script
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script indented
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on lambda(a, x)
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set strIndent to leftSpace of a
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{rows:strIndent & x & linefeed & rows of a, leftSpace:leftSpace of a & " "}
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end lambda
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end script
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rows of foldr(indented, {rows:"", leftSpace:""}, map(spaced, lstTriangle))
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end run
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-- GENERIC LIBRARY FUNCTIONS
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-- foldr :: (a -> b -> a) -> a -> [b] -> a
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on foldr(f, startValue, xs)
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tell mReturn(f)
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set v to startValue
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set lng to length of xs
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repeat with i from lng to 1 by -1
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set v to lambda(v, item i of xs, i, xs)
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end repeat
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return v
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end tell
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end foldr
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-- map :: (a -> b) -> [a] -> [b]
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on map(f, xs)
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tell mReturn(f)
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set lng to length of xs
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set lst to {}
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repeat with i from 1 to lng
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set end of lst to lambda(item i of xs, i, xs)
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end repeat
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return lst
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end tell
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end map
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-- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
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on zipWith(f, xs, ys)
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set nx to length of xs
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set ny to length of ys
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if nx < 1 or ny < 1 then
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{}
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else
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set lng to cond(nx < ny, nx, ny)
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set lst to {}
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tell mReturn(f)
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repeat with i from 1 to lng
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set end of lst to lambda(item i of xs, item i of ys)
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end repeat
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return lst
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end tell
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end if
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end zipWith
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-- cond :: Bool -> (a -> b) -> (a -> b) -> (a -> b)
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on cond(bool, f, g)
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if bool then
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f
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else
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g
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end if
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end cond
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-- intercalate :: Text -> [Text] -> Text
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on intercalate(strText, lstText)
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set {dlm, my text item delimiters} to {my text item delimiters, strText}
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set strJoined to lstText as text
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set my text item delimiters to dlm
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return strJoined
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end intercalate
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-- range :: Int -> Int -> [Int]
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on range(m, n)
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set lng to (n - m) + 1
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set base to m - 1
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set lst to {}
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repeat with i from 1 to lng
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set end of lst to i + base
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end repeat
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return lst
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end range
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-- Lift 2nd class handler function into 1st class script wrapper
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-- mReturn :: Handler -> Script
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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 lambda : f
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end script
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end if
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end mReturn
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