var fs = require('fs');
-type Some<T> = { _tag: "Some"; value: T };
-type None = {_tag: "None"};
+import * as tk from './tokenize.js';
-/**
- * @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;
-/**
- * @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};
+let b : Array<tk.Token> = tk.tokenize("2+2");
+
+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)=>{
- const charToBeMatched = m.remained[0];
- if (charToBeMatched === c){
- return {_tag: "Some", value :{
- matched : m.matched + charToBeMatched,
- remained : m.remained.substring(1)}};
+export function match1token(t: tk.Token): (m: TokenMatcheePair) => tk.Maybe<TokenMatcheePair> {
+ return (m: TokenMatcheePair) => {
+ if (m.remained.length == 0) {
+ return { _tag: "None" };
}
- 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
- */
-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);
- }
-}
+
+let c = tk.toSome(b);
+console.log(thenDo(c,match1token(tk.tokenize("+")[0])));
\ No newline at end of file