Closures/Value capture: Difference between revisions

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@@ Line 84: / Line 84: @@
 =={{header|AppleScript}}==
 {{trans|JavaScript}}
 <lang AppleScript>on run
     set fns to {}
@@ Line 94: / Line 92: @@
     end repeat
-    lambda() of item 3 of fns
+    |λ|() of item 3 of fns
 end run
 on closure(x)
     script
-        on lambda()
+        on |λ|()
-            return x * x
+            x * x
-        end lambda
+        end |λ|
     end script
 end closure</lang>
 {{Out}}
 <pre>9</pre>
 Or, in a more functional pattern of composition:
+<lang AppleScript>-- CLOSURE --------------------------------------------------------------------
-<lang AppleScript>on run
+script closure
-    lambda() of (item 3 of (map(closure, range(1, 10))))
+    on |λ|(x)
+        script
-end run
+            on |λ|()
+                x * x
+            end |λ|
+        end script
+    end |λ|
+end script
+|λ|() of (item 3 of (map(closure, enumFromTo(1, 10))))
-on closure(x)
-    script
-        on lambda()
-            return x * x
-        end lambda
-    end script
-end closure
+-- GENERIC FUNCTIONS ----------------------------------------------------------
+-- enumFromTo :: Int -> Int -> [Int]
--- GENERIC FUNCTIONS
+on enumFromTo(m, n)
+    if n < m then
+        set d to -1
+    else
+        set d to 1
+    end if
+    set lst to {}
+    repeat with i from m to n by d
+        set end of lst to i
+    end repeat
+    return lst
+end enumFromTo
 -- map :: (a -> b) -> [a] -> [b]
 on map(f, xs)
-    script mf
+    tell mReturn(f)
-        property lambda : f
+        set lng to length of xs
-    end script
+        set lst to {}
+        repeat with i from 1 to lng
-    set lng to length of xs
-    set lst to {}
+            set end of lst to |λ|(item i of xs, i, xs)
-    repeat with i from 1 to lng
+        end repeat
-        set end of lst to mf's lambda(item i of xs, i, xs)
+        return lst
-    end repeat
+    end tell
-    return lst
 end map
+-- Lift 2nd class handler function into 1st class script wrapper
--- range :: Int -> Int -> Int
+-- mReturn :: Handler -> Script
-on range(m, n)
+on mReturn(f)
-    set lng to (n - m) + 1
+    if class of f is script then
-    set base to m - 1
+        f
-    set lst to {}
+    else
-    repeat with i from 1 to lng
+        script
-        set end of lst to i + base
+            property |λ| : f
-    end repeat
+        end script
-    return lst
+    end if
-end range
+end mReturn</lang>
-</lang>
 {{Out}}
 <pre>9</pre>