add a method to initialize a 2D matrix from a linear array. Will be v…

…ery useful for HLLs that need to instantiate array constants

src/pmc/nummatrix2d.pmc

@@ -486,6 +486,23 @@ pmclass NumMatrix2D dynpmc auto_attrs {
         attrs->storage = new_s;
         free(old_s);
     }
+
+    METHOD initialize_from_array(INTVAL x_size, INTVAL y_size, PMC *values) {
+        Parrot_NumMatrix2D_attributes * const attrs = PARROT_NUMMATRIX2D(SELF);
+        FLOATVAL * const s = attrs->storage;
+        INTVAL x = attrs->x;
+        INTVAL y = attrs->y;
+        INTVAL i, j, num = 0;
+        resize_matrix(INTERP, SELF, x_size - 1, y_size - 1);
+        for (i = 0; i < y_size; i++) {
+            for (j = 0; j < x_size; j++) {
+                FLOATVAL value = VTABLE_get_number_keyed(INTERP, values, num);
+                num++;
+                ITEM_XY_ROWMAJOR(s, x, y, j, i) = value;
+            }
+        }
+    }
+
 /*
 
 =back