2016 Update

Task/Variables/00DESCRIPTION

@@ -1 +1,10 @@
-Demonstrate the language's methods of variable declaration, initialization, assignment, datatypes, scope, referencing, and other variable related facilities.
+;Task:
+Demonstrate a language's methods of:
+:::*   variable declaration
+:::*   initialization
+:::*   assignment
+:::*   datatypes
+:::*   scope
+:::*   referencing,     and
+:::*   other variable related facilities
+<br><br>

Task/Variables/360-Assembly/variables-1.360

@@ -0,0 +1,6 @@
+*        value of F
+         L      2,F                assigment      r2=f
+*        reference (or address) of F
+         LA     3,F                reference      r3=@f
+*        referencing (or indexing) of reg3       (r3->f)
+         L      4,0(3)             referencing    r4=%r3=%@f=f

Task/Variables/360-Assembly/variables-2.360

@@ -0,0 +1,24 @@
+*        declarations                             length
+C        DS     C                  character        1
+X        DS     X                  character hexa   1
+B        DS     B                  character bin    1
+H        DS     H                  half word        2
+F        DS     F                  full word        4
+E        DS     F                  single float     4
+D        DS     D                  double float     8
+L        DS     L                  extended float  16
+S        DS     CL12               string          12
+P        DS     PL16               packed decimal  16
+Z        DS     ZL32               zoned  decimal  32
+*        declarations + initialization
+CI       DC     C'7'               character        1
+XI       DC     X'F7'              character hexa   1
+BI       DC     B'11110111'        character bin    1
+HI       DC     H'7'               half word        2
+FI       DC     F'7'               full word        4
+EI       DC     F'7.8E3'           single float     4
+DI       DC     D'7.8E3'           double float     8
+LI       DC     L'7.8E3'           extended float  16
+SI       DC     CL12'789'          string          12
+PI       DC     PL16'7'            packed decimal  16
+ZI       DC     ZL32'7'            zoned decimal   32

Task/Variables/Ada/variables.ada

@@ -1,7 +1,19 @@
-declare
+Name: declare   -- a local declaration block has an optional name
+   A : constant Integer := 42;  -- Create a constant
    X : String := "Hello"; -- Create and initialize a local variable
-   Y : Integer; -- Create an uninitialized variable
+   Y : Integer;           -- Create an uninitialized variable
    Z : Integer renames Y: -- Rename Y (creates a view)
+   function F (X: Integer) return Integer is
+     -- Inside, all declarations outside are visible when not hidden: X, Y, Z are global with respect to F.
+     X: Integer := Z;  -- hides the outer X which however can be refered to by Name.X
+   begin
+     ...
+   end F;  -- locally declared variables stop to exist here
 begin
    Y := 1; -- Assign variable
-end; -- End of the scope
+   declare
+     X: Float := -42.0E-10;  -- hides the outer X (can be referred to Name.X like in F)
+   begin
+     ...
+   end;
+end Name; -- End of the scope

Task/Variables/Elena/variables.elena

@@ -0,0 +1,8 @@
+#symbol program =
+[
+   #var c.                         // declaring variable. default value is $nil
+   #var a := 3.                    // declaring and initializing variables
+   #var b := "my string" length.
+
+   c := b + a.                     // assigning variable
+].

Task/Variables/Forth/variables-4.fth

@@ -0,0 +1,3 @@
+VARIABLE X   999 X !                \ create variable x, store 999 in X
+VARIABLE Y   -999 Y !               \ create variable y, store -999 in Y
+2VARIABLE W  140569874. W 2!        \ create and assign a double precision variable

Task/Variables/MATLAB/variables-1.m

@@ -8,8 +8,8 @@
         u32 = uint32(5);% unsigned 4 byte integers
         i64 = int64(5);	% signed 8 byte integer
         u64 = uint64(5);% unsigned 8 byte integer
-	f32 = float32(5); % single precission floating point number
-	f64 = float64(5); % double precission floating point number , float 64 is the default data type.
+	f32 = float32(5); % single precision floating point number
+	f64 = float64(5); % double precision floating point number , float 64 is the default data type.
 
 	c = 4+5i; %	complex number
         colvec = [1;2;4];   % column vector

Task/Variables/Maple/variables-1.maple

@@ -0,0 +1,3 @@
+a := 1:
+print ("a is "||a);
+                            "a is 1"

Task/Variables/Maple/variables-2.maple

@@ -0,0 +1,10 @@
+b;
+f := proc()
+    local b := 3;
+    print("b is "||b);
+end proc:
+f();
+print("b is "||b);
+                               b
+                            "b is 3"
+                            "b is b"

Task/Variables/Maple/variables-3.maple

@@ -0,0 +1,11 @@
+f := proc()
+    global c;
+    c := 3;
+    print("a is "||a);
+    print("c is "||c);
+end proc:
+f();
+print("c is "||c);
+                            "a is 1"
+                            "c is 3"
+                            "c is 3"

Task/Variables/Maple/variables-4.maple

@@ -0,0 +1,5 @@
+print ("a is "||a);
+a := 4:
+print ("a is "||a);
+                            "a is 1"
+                            "a is 4"

Task/Variables/Maple/variables-5.maple

@@ -0,0 +1,11 @@
+print ("a is "||a);
+type(a, integer);
+a := "Hello World":
+print ("a is "||a);
+type(a, integer);
+type(a, string);
+                            "a is 4"
+                              true
+                       "a is Hello World"
+                             false
+                              true

Task/Variables/Maple/variables-6.maple

@@ -0,0 +1,3 @@
+`This is a variable` := 1:
+print(`This is a variable`);
+                               1

Task/Variables/Maple/variables-7.maple

@@ -0,0 +1,14 @@
+print ("a is "||a);
+type(a, string);
+print("c is "||c);
+a := 'a':
+print ("a is "||a);
+type(a, symbol);
+unassign('c');
+print("c is "||c);
+                       "a is Hello World"
+                              true
+                            "c is 3"
+                            "a is a"
+                              true
+                            "c is c"

Task/Variables/Prolog/variables-1.pro

@@ -0,0 +1,2 @@
+mortal(X) :- man(X).
+man(socrates).

Task/Variables/Prolog/variables-2.pro

@@ -0,0 +1,2 @@
+student(X,Y) :- taught(Y,X).
+taught(socrates,plato).

Task/Variables/Prolog/variables-3.pro

@@ -0,0 +1,6 @@
+?- mortal(socrates).
+yes
+?- student(X,socrates).
+X=plato
+?- student(socrates,X).
+no

Task/Variables/Prolog/variables-4.pro

@@ -0,0 +1,2 @@
+?- mortal(zeus).
+no

Task/Variables/Prolog/variables-5.pro

@@ -0,0 +1 @@
+mortal(X) :- man(Y).