var fs = require('fs');
-export type Some<T> = { _tag: "Some"; value: T };
-export type None = {_tag: "None"};
+import * as tk from './tokenize.js';
-/**
- * wrap a x in a `Some(T)`
- * @param x : variable to be wrapped.
- * @returns wrapped `x`.
- */
-function toSome<T>(x: T): Some<T>{
- return { _tag: "Some", value: x};
-}
-/**
- * @description Like the `Some(a)` and `None` in Rust.
- *
- * @example
- * ```ts
- * let exam1 : Maybe<Number> = { _tag: "Some", value: 12 };
- * let exam2 : Maybe<Number> = None;
- * ```
- */
-export type Maybe<T> = Some<T> | None;
+let b : Array<tk.Token> = tk.tokenize("2+2");
-/**
- * @description
- * the pair of the string to be matched later and the string that have been matched
- * @param matched : string have been matched
- * @param remained : string will be tested whether it'll be matched.
- */
-export type MatcheePair = {matched : string; remained : string};
+export interface TokenMatcheePair {
+ matched: tk.Token[]
+ remained: tk.Token[]
+}
/**
* @description
* it returns a function which test if the first char of the `remained` part of
* the argument of the function is `c`, if it's true, update the `MatchedPair` wrapped
* in `Some`. Otherwise, it returns `None`.
- * * @param c : the char to be test.
+ * * @param t : the char to be test.
* @returns the updated `MatchedPair` wrapped in `Some(x)` or `None`.
*/
-export function match1Char(c : string) : (m: MatcheePair) => Maybe<MatcheePair> {
- return (m : MatcheePair)=>{
- if (m.remained.length == 0){
+export function match1token(t: tk.Token): (m: TokenMatcheePair) => tk.Maybe<TokenMatcheePair> {
+ return (m: TokenMatcheePair) => {
+ if (m.remained.length == 0) {
return { _tag: "None" };
}
- const charToBeMatched = m.remained[0];
- if (charToBeMatched === c){
- return {_tag: "Some", value :{
- matched : m.matched + charToBeMatched,
- remained : m.remained.substring(1)}};
- }
- else{
- return {_tag: "None"};
- }
- }
-};
-
-/**
- *
- * @param m : the `MatcheePair` to be consumed.
- * @returns if the length of `m.remained` >= 1; consumes the matchee by 1 char and wraps it in `Some`,
- * otherwise, returns `None`.
- */
-export function matchAny(m : MatcheePair) : Maybe<MatcheePair>{
- if (m.remained.length >= 1){
- return {_tag: "Some", value :{
- matched : m.matched + m.remained[0],
- remained : m.remained.substring(1)}};
- }else{
- return {_tag: "None"};
- }
-}
-
-/**
- * @description
- * it returns a function which test if the first char of the `remained` part of
- * the argument of the function is between `l` and `u`, if it's true, update the `MatchedPair` wrapped
- * in `Some`. Otherwise, it returns `None`.
- * * @param l : lower bound char, 1-char string
- * * @param u : upper bound char, 1-char string
- * @returns the updated `MatchedPair` wrapped in `Some(x)` or `None`.
- */
-export function matchRange(l : string, u : string) : (m: MatcheePair) => Maybe<MatcheePair> {
- let lCodepoint = charToCodepoint(l);
- let uCodepoint = charToCodepoint(u);
- if (l > u){
- throw new Error("Error: the codepoint of `"+l+"` is not smaller than `"+u+"`)");
- }
- return (m : MatcheePair)=>{
- if (m.remained.length < 1){
- return {_tag : "None"};
- }
- const charToBeMatched = m.remained[0];
- const codePointToBeMatched = charToCodepoint(charToBeMatched);
- if (codePointToBeMatched >= lCodepoint && codePointToBeMatched <= uCodepoint){
- return {_tag: "Some", value :{
- matched : m.matched + charToBeMatched,
- remained : m.remained.substring(1)}};
- }
- else{
- return {_tag: "None"};
+ const tokenToBeMatched = m.remained[0];
+ if (tokenToBeMatched === t) {
+ m.matched.push(tokenToBeMatched);
+ return {
+ _tag: "Some", value: {
+ matched: m.matched,
+ remained: m.remained.slice(1)
+ }
+ };
+ }
+ else {
+ return { _tag: "None" };
}
}
};
-/**
- * convert the one-char string to codepoint.
- * @param s : the string to code point.
- * @returns if `s.length > 1` return error; otherwise, return the codepoint of `s`.
- */
-export function charToCodepoint(s : string): number{
- if (s.length > 1){
- throw new Error("Error: the length of input string for "+s+ "is "+s.length+`,
- however, it should be 1.`);
- }else{
- return s.charCodeAt(0);
- }
-}
-/**
- * @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: @, {, }.
-
-}
-tokenize("+123");
-tokenize("123");
-tokenize("-123");
-tokenize(" 123");
-tokenize("c123");
\ No newline at end of file
+let c = tk.toSome(b);
+console.log(thenDo(c,match1token(tk.tokenize("+")[0])));
\ No newline at end of file