-/**
- * @description thendo(input, f, ...) like
- * a ==> f
- * @param input: the wrapped input.
- * @param f: the function to be applied.
- *
- * @returns:the applied wrapped result `MatcheePair`.
- */
-export function thenDo<T>(input : Maybe<T>, f : Function) : Maybe<T>{
- if (input._tag == "None"){
- return input;
- }
- else{
- let inner = input.value;
- return f(inner);
- }
-}
-
-/**
- * @description "or", like the regex `( f1 | f2 )` .
- * It returns a function `f` of which the argument is`x`.
- * if `f1(x)` is None, then `f` returns `f2(x)`. Otherwise,
- * `F` returns `f1(x)`.
- * @param f1 : 1st function to be compared
- * @param f2 : 2nd function to be compared
- * @returns:the combined function
- */
-export function orDo<T>(f1 : Function, f2: Function) : (x : T ) => Maybe<T>{
- return (x) => {
- let f1x : Maybe<T> = (f1(x));
- {
- if (f1x._tag == "None"){
- return f2(x);
- }
- else{
- return f1x;
- }
- }
- };
-}
-
-
-/**
-* @description repeating matching function `f`
-* zero or more times, like the asterisk `*` in regex `f*` .
-* @param f : the function to be repeated 0+ times.
-* @returns:the combined function
-*/
-export function zeroOrMoreDo<T>(f : Function): (x : T) => Maybe<T>{
- return (x)=>{
- var wrapped_old_x : Maybe<T> = {_tag: "Some", value : x};
- var wrapped_new_x : Maybe<T> = wrapped_old_x;
-
- while (wrapped_new_x._tag != "None"){
- wrapped_old_x = wrapped_new_x;
- wrapped_new_x = thenDo(wrapped_old_x, f);
- };
-
- return wrapped_old_x;
- };
-}
-
-/**
-* @description Not. like the `^` inside regex of [^f].
-* returns a function `F(x)` such that if `f(x)` is `None`,
-* returns the x consuming a char; if `f(x)` is not None, F(x)
-* returns `None`.
-* @param f: the function forbidden to be matched.
-* @returns: combined function `F`.
-*/
-export function notDo<T>(f : Function): (x : T) => Maybe<T>{
- return (x)=>{
- let wrapped_x : Maybe<T> = {
- _tag : "Some",
- value : x
- };
- let f_x = thenDo(wrapped_x, f);
-
- if (f_x._tag != "None"){
- return {_tag:"None"};
- }else{
- return thenDo(wrapped_x, matchAny);
- }
- };
-}
-
-/**
- * if `x` is matched by `f` once, returns `f(x)`. Otherwise,
- * returns x
- * similar to `?` in regex `f?`.
- * @param f : the function to be matched
- * @returns return wrapped f(x)
- */
-export function zeroOrOnceDo<T>(f : Function): (x : T) => Maybe<T>{
- return (x)=>{
- var wrapped_old_x : Maybe<T> = {_tag: "Some", value : x};
- var wrapped_new_x = thenDo(wrapped_old_x, f);
-
- if (wrapped_new_x._tag != "None"){
- return wrapped_new_x;
- }else{
- return wrapped_old_x;
- }
- };
-}
-
-
-export function tokenize(input : string){
- var input_matchee_pair : Maybe<MatcheePair> = toSome(
- {matched:"",
- remained: input});
-
- // integer = ([+]|[-])?\d\d*
- let integer = (x : MatcheePair) =>
- { let wrapped_x = toSome(x);
- let plusMinus = orDo(match1Char('+'), match1Char('-')); // ([+]|[-])
- let d = matchRange('0','9'); // \d
- return thenDo(thenDo(thenDo(wrapped_x,
- zeroOrOnceDo(plusMinus)),d),
- zeroOrMoreDo(d));
- }
- console.log(input+", result: ");
- console.log(thenDo(input_matchee_pair, integer));
- // TODO: id, string, space, basic operator, 3 marks: @, {, }.
-
-}