lazy paths for Babel support

compiler/patterns.nim

@@ -237,6 +237,15 @@ proc addToArgList(result, n: PNode) =
     else:
       for i in 0 .. <n.len: result.add(n.sons[i])
 
+when false:
+  proc procPatternMatches*(c: PContext, s: PSym, n: PNode): bool =
+    ## for AST-based overloading:
+    var ctx: TPatternContext
+    ctx.owner = s
+    ctx.c = c
+    ctx.formals = sonsLen(s.typ)-1
+    result = matches(ctx, s.ast.sons[patternPos], n)
+
 proc applyRule*(c: PContext, s: PSym, n: PNode): PNode =
   ## returns a tree to semcheck if the rule triggered; nil otherwise
   var ctx: TPatternContext