added scarpet c_for loops

docs/scarpet/Full.md

@@ -985,6 +985,20 @@ Please check corresponding loop function description what `continue` and `break`
 general case, passed values to `break` and `continue` will be used in place of the return value of the internal 
 iteration expression.
 
+### `cfor(init, condition, increment, body)`
+
+`c_for` Mimics c-style tri-arg (plus body) for loops. Return value of `c_for` is number of iterations performed in the
+ loop. Unlike other loops, the `body` is not provided with pre-initialized `_` style variables - all initialization
+ and increments has to be handled by the programmers themselves.
+ 
+ <pre>
+ c_for(x=0, x<10, x+=1,
+    c_for(y=0, y<10, y+=1,
+        print(str('%d * %d = %d', x, y, x*y))
+    )
+ )
+ </pre> 
+
 ### `for(list,expr(_,_i))`
 
 Evaluates expression over list of items from the `list`. Supplies `_`(value) and `_i`(iteration number) to the `expr`.

docs/scarpet/language/LoopsAndHigherOrderFunctions.md

@@ -19,6 +19,20 @@ Please check corresponding loop function description what `continue` and `break`
 general case, passed values to `break` and `continue` will be used in place of the return value of the internal 
 iteration expression.
 
+### `cfor(init, condition, increment, body)`
+
+`c_for` Mimics c-style tri-arg (plus body) for loops. Return value of `c_for` is number of iterations performed in the
+ loop. Unlike other loops, the `body` is not provided with pre-initialized `_` style variables - all initialization
+ and increments has to be handled by the programmers themselves.
+ 
+ <pre>
+ c_for(x=0, x<10, x+=1,
+    c_for(y=0, y<10, y+=1,
+        print(str('%d * %d = %d', x, y, x*y))
+    )
+ )
+ </pre> 
+
 ### `for(list,expr(_,_i))`
 
 Evaluates expression over list of items from the `list`. Supplies `_`(value) and `_i`(iteration number) to the `expr`.

src/main/java/carpet/script/Expression.java

@@ -1081,6 +1081,32 @@ public class Expression
             return result;
         });
 
+        // runs traditional for(init, condition, increment, body) tri-argument for loop with body in between
+        addLazyFunction("c_for", 4, (c, t, lv) -> {
+            LazyValue initial = lv.get(0);
+            LazyValue condition = lv.get(1);
+            LazyValue increment = lv.get(2);
+            LazyValue body = lv.get(3);
+            int iterations = 0;
+            for (initial.evalValue(c, Context.VOID); condition.evalValue(c, Context.BOOLEAN).getBoolean(); increment.evalValue(c, Context.VOID))
+            {
+                try
+                {
+                    body.evalValue(c, Context.VOID);
+                }
+                catch (BreakStatement stmt)
+                {
+                    break;
+                }
+                catch (ContinueStatement ignored)
+                {
+                }
+                iterations++;
+            }
+            int finalIterations = iterations;
+            return (cc, tt) -> new NumericValue(finalIterations);
+        });
+
         // similar to map, but returns total number of successes
         // for(list, expr) => success_count
         // can be substituted for first and all, but first is more efficient and all doesn't require knowing list size