init ps6

exercises/06/vslc/vsl_programs/ps6-codegen2/euclid.vsl

@@ -0,0 +1,20 @@
+func euclid ( a, b )
+begin
+    if a < 0 then a := -a
+    if b < 0 then b := -b
+    if gcd ( a, b ) > 1 then
+        print "Greatest common divisor of", a, "and", b, "is", gcd ( a, b )
+    else
+        print a, "and", b, "are relative primes"
+    return 0
+end
+
+func gcd( a, b )
+begin
+    var g
+    if b > 0 then
+        g := gcd ( b, a - ((a/b)*b) )
+    else
+        g := a
+    return g
+end

exercises/06/vslc/vsl_programs/ps6-codegen2/newton.vsl

@@ -0,0 +1,21 @@
+// Approximate square root by the Newton/Raphson method for f(x) = x^2 - n
+// f(x) = x^2 - n = 0
+// f'(x) = 2x
+// x{n+1} = x{n} - (x^2-n) / 2x 
+
+func newton ( n )
+begin
+    print "The square root of", n, "is", improve ( n, 1 )
+    return 0
+end
+
+func improve ( n, estimate )
+begin
+    var next
+    next := estimate - ( (estimate * estimate - n) / ( 2 * estimate ) )
+    if next - estimate = 0 then
+        // Integer precision converges at smallest int greater than the square
+        return next-1
+    else
+        return improve ( n, next )
+end

exercises/06/vslc/vsl_programs/ps6-codegen2/while_test.vsl

@@ -0,0 +1,23 @@
+// This program is a simple test of while loops, counting down from 19 to 0
+// and skipping 10 (if continue is implemented)
+
+func while_test ()
+begin
+    var a
+    a := 20
+    print a
+    if a > 0 then print "foobar"
+    while a > 0 do
+    begin
+        if a = 10 then
+        begin
+            a -= 1
+            print "Skip..."
+            continue
+        end
+        else
+            a -= 1
+        print a
+    end
+    return 0
+end