September 2017 Update

Task/Filter/APL/filter.apl

@@ -0,0 +1,2 @@
+      (0=2|x)/x←⍳20
+2 4 6 8	10 12 14 16 18 20

Task/Filter/AppleScript/filter-3.applescript

@@ -1,30 +1,40 @@
 -- filter :: (a -> Bool) -> [a] -> [a]
--- filter :: (a -> Int -> Bool) -> [a] -> [a]
--- filter :: (a -> Int -> [a] -> Bool) -> [a] -> [a]
 on filter(f, xs)
-    script mf
-        property lambda : f
-    end script
-
-    set lst to {}
-    set lng to length of xs
-    repeat with i from 1 to lng
-        set v to item i of xs
-        if mf's lambda(v, i, xs) then
-            set end of lst to v
-        end if
-    end repeat
-    return lst
+    tell mReturn(f)
+        set lst to {}
+        set lng to length of xs
+        repeat with i from 1 to lng
+            set v to item i of xs
+            if |λ|(v, i, xs) then set end of lst to v
+        end repeat
+        return lst
+    end tell
 end filter
 
-
--- Ordinary AppleScript predicate function, rather than a script object
+-- TEST -----------------------------------------------------------------------
 
 -- isEven :: (a -> Bool)
 on isEven(x)
     x mod 2 = 0
 end isEven
 
-set lstRange to {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+on run
 
-filter(isEven, lstRange)
+    filter(isEven, {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10})
+
+    -- {0, 2, 4, 6, 8, 10}
+end run
+
+-- GENERIC FUNCTION -----------------------------------------------------------
+
+-- Lift 2nd class handler function into 1st class script wrapper
+-- mReturn :: Handler -> Script
+on mReturn(f)
+    if class of f is script then
+        f
+    else
+        script
+            property |λ| : f
+        end script
+    end if
+end mReturn

Task/Filter/Batch-File/filter.bat

@@ -0,0 +1,58 @@
+@echo off
+setlocal enabledelayedexpansion
+
+set numberarray=1 2 3 4 5 6 7 8 9 10
+for %%i in (%numberarray%) do (
+  set /a tempcount+=1
+  set numberarray!tempcount!=%%i
+)
+
+echo Filtering all even numbers from numberarray into newarray...
+call:filternew numberarray
+echo numberarray - %numberarray%
+echo newarray    -%newarray%
+echo.
+echo Filtering numberarray so that only even entries remain...
+call:filterdestroy numberarray
+echo numberarray -%numberarray%
+pause>nul
+exit /b
+
+:filternew
+set arrayname=%1
+call:arraylength %arrayname%
+set tempcount=0
+for /l %%i in (1,1,%length%) do (
+  set /a cond=!%arrayname%%%i! %% 2
+  if !cond!==0 (
+    set /a tempcount+=1
+    set newarray!tempcount!=!%arrayname%%%i!
+    set newarray=!newarray! !%arrayname%%%i!
+  )
+)
+exit /b
+
+:filterdestroy
+set arrayname=%1
+call:arraylength %arrayname%
+set tempcount=0
+set "%arrayname%="
+for /l %%i in (1,1,%length%) do (
+  set /a cond=!%arrayname%%%i! %% 2
+  if !cond!==0 (
+    set /a tempcount+=1
+    set %arrayname%!tempcount!=!%arrayname%%%i!
+    set %arrayname%=!%arrayname%! !%arrayname%%%i!
+  )
+)
+exit /b
+
+:arraylength
+set tempcount=0
+set lengthname=%1
+set length=0
+:lengthloop
+set /a tempcount+=1
+if "!%lengthname%%tempcount%!"=="" exit /b
+set /a length+=1
+goto lengthloop

Task/Filter/Gambas/filter.gambas

@@ -0,0 +1,43 @@
+sRandom As New String[]
+'______________________________________________________________________________________________________
+Public Sub Main()
+Dim siCount As Short
+
+For siCount = 0 To 19
+  sRandom.Add(Rand(1, 100))
+Next
+
+Print sRandom.join(",")
+
+NewArray
+Destructive
+
+End
+'______________________________________________________________________________________________________
+Public Sub NewArray() 'Select certain elements from an array into a new array in a generic way
+Dim sEven As New String[]
+Dim siCount As Short
+
+For siCount = 0 To sRandom.Max
+  If Even(sRandom[siCount]) Then sEven.Add(sRandom[siCount])
+Next
+
+Print sEven.join(",")
+
+End
+'______________________________________________________________________________________________________
+Public Sub Destructive() 'Give a second solution which filters destructively
+Dim siIndex As New Short[]
+Dim siCount As Short
+
+For siCount = 0 To sRandom.Max
+  If Odd(sRandom[siCount]) Then siIndex.Add(siCount)
+Next
+
+For siCount = siIndex.max DownTo 0
+  sRandom.Extract(siIndex[siCount], 1)
+Next
+
+Print sRandom.join(",")
+
+End

Task/Filter/JavaScript/filter-5.js

@@ -0,0 +1,14 @@
+(() => {
+    'use strict';
+
+    // isEven :: Int -> Bool
+    const isEven = n => n % 2 === 0;
+
+
+    // TEST
+
+    return [1,2,3,4,5,6,7,8,9]
+        .filter(isEven);
+
+    // [2, 4, 6, 8]
+})();

Task/Filter/JavaScript/filter-6.js

@@ -0,0 +1 @@
+[2, 4, 6, 8]

Task/Filter/Kotlin/filter.kotlin

@@ -0,0 +1,13 @@
+// version 1.0.5-2
+
+fun main(args: Array<String>) {
+    val array = arrayOf(1, 2, 3, 4, 5, 6, 7, 8, 9)
+    println(array.joinToString(" "))
+
+    val filteredArray = array.filter{ it % 2 == 0 }
+    println(filteredArray.joinToString(" "))
+
+    val mutableList = array.toMutableList()
+    mutableList.retainAll { it % 2 == 0 }
+    println(mutableList.joinToString(" "))
+}

Task/Filter/Maple/filter.maple

@@ -0,0 +1,3 @@
+evennum:=proc(nums::list(integer))
+	return select(x->type(x, even), nums);
+end proc;

Task/Filter/OoRexx/filter.rexx

@@ -0,0 +1,31 @@
+ Call random ,,1234567
+ a=.array~new
+ b=.array~new
+ Do i=1 To 10
+   a[i]=random(1,9999)
+   End
+ Say 'Unfiltered values:' a~makestring(line,' ')
+ /* copy even numbers to array b */
+ j=0
+ Do i=1 to 10
+   If filter(a[i]) Then Do
+     j = j + 1
+     b[j]=a[i]
+     End
+   end
+ Say 'Filtered values (in second array):      ' b~makestring(line,' ')
+ /* destructive filtering: copy within array a */
+ j=0
+ Do i=1 to 10
+   If filter(a[i]) Then Do
+     j = j + 1
+     a[j]=a[i]
+     End
+   end
+ /* destructive filtering: delete the remaining elements */
+ Do i=10 To j+1 By -1
+   a~delete(i)
+   End
+ Say 'Filtered values (destructive filtering):' a~makestring(line,' ')
+ Exit
+ filter: Return arg(1)//2=0

Task/Filter/Protium/filter.protium

@@ -1,8 +0,0 @@
-<@ LETCNWLSTLIT>numbers|1 2 3 4 5 6 7 8 9 10 11 12</@>
-<@ DEFLST>evens</@>
-<@ ENULSTLIT>numbers|
-<@ TSTEVEELTLST>...</@>
-<@ IFF>
-<@ LETLSTELTLST>evens|...</@>
-</@>
-</@>

Task/Filter/Ruby/filter-2.rb

@@ -1,9 +1,3 @@
-# Integer#even? is new to Ruby 1.8.7.
-# Define it for older Ruby.
-unless Integer.method_defined? :even?
-  class Integer
-    def even?
-      self % 2 == 0
-    end
-  end
-end
+ary = [1, 2, 3, 4, 5, 6]
+ary.select! {|elem| elem.even?}
+p ary # => [2, 4, 6]

Task/Filter/Ruby/filter-3.rb

@@ -1,3 +0,0 @@
-ary = [1, 2, 3, 4, 5, 6]
-ary.select! {|elem| elem.even?}
-p ary # => [2, 4, 6]

Task/Filter/Ruby/filter-4.rb

@@ -1,11 +0,0 @@
-# Array#select! is new to Ruby 1.9.2.
-# Define it for older Ruby.
-unless Array.method_defined? :select!
-  class Array
-    def select!
-      enum_for(:select!) unless block_given?
-      delete_if { |elem| not yield elem }
-      self
-    end
-  end
-end

Task/Filter/Standard-ML/filter.ml

@@ -1,2 +0,0 @@
-val ary = [1,2,3,4,5,6];
-List.filter (fn x => x mod 2 = 0) ary

Task/Filter/Stata/filter.stata

@@ -0,0 +1,9 @@
+mata
+a=2,9,4,7,5,3,6,1,8
+
+// Select even elements of a
+select(a,mod(a,2):==0)
+
+// Select the indices of even elements of a
+selectindex(mod(a,2):==0)
+end

Task/Filter/Zkl/filter.zkl

@@ -0,0 +1,3 @@
+T(1,4,9,16,25,36,"37",49,64,81,100, True,self)
+   .filter(fcn(n){(0).isType(n) and n.isOdd})
+//-->L(1,9,25,49,81)