+
+let circumfix = (f : Function, signal? : string) => (x : TokenMatcheePair)=>{
+ var a = f(x);
+ if (a._tag == "Some"){
+ let inner = a.value.ast[a.value.ast.length-2];
+ console.log("AST===="+repr(a.value.ast));
+ let ast_middle : tkTree[] = [inner];
+ let new_ast = [ast_middle];
+ a.value.ast = new_ast;
+
+ console.log("+"+signal+"+"+repr(a));
+
+
+ }
+ return a;
+}
+
+/** fac1 = "(" expr ")" */
+let fac1 = circumfix((x : TokenMatcheePair)=>
+thenDo(thenDo(thenDo(tk.toSome(x), tLParen), expr), tRParen), "fac1");
+
+let fac2 = tInt;
+
+let fac = orDo(fac1, fac2);
+
+
+
+/**
+ *
+ * term1 = fac (MUL | DIV) fac
+ */
+
+let term1 = midfix((x : TokenMatcheePair)=>
+ thenDo(thenDo(thenDo(tk.toSome(x), fac), orDo(tMul,tDiv)), fac), "term1");
+
+
+/**
+ *
+ * term2 = int MUL int
+ */
+let term2 = fac;
+
+/**
+ * term = term1 | term2
+ */
+let term = orDo(term1, term2);
+
+
+/**
+ *
+ * expr1 = term ADD term
+ */
+let expr1 = midfix((x : TokenMatcheePair)=>
+ thenDo(thenDo(thenDo(tk.toSome(x), term), orDo(tAdd,tSub)), term), "expr1");
+/**
+ * expr2 = term
+ */
+let expr2 = term;
+
+/**
+ * expr = expr1 | expr2
+ */
+let expr = orDo(expr1, expr2);
+
+
+
+
+let tokens = tk.tokenize("(4-(3/4))");//tk.tokenize(argv[2]);
+let tokensFiltered = tokens.filter(
+ (x)=>{return (x.type != tk.TokenType.NL
+ && x.type != tk.TokenType.SP)});
+
+let wrappedTokens : tk.Maybe<TokenMatcheePair> =
+ tk.toSome({
+ matched : [] ,
+ remained : tokensFiltered,
+ ast : []});
+
+let beta = expr({
+ matched : [] ,
+ remained : tokensFiltered,
+ ast : []});
+
+
+console.log(repr(beta));
+