@parser-generator/grammar-interpreter/lib/esm/__tests__/test.js

A Parser Generator that supports LL,SLR,LR1,LALR

import { NonTerminal, Production, SymbolWrapper, EOF, ParsingTable, Goto, Shift, Accept, Reduce } from "@parser-generator/definition";
class IfStmt {
    constructor(children) {
        this.children = children;
    }
    toString() {
        return "(" + this.children.join(" ") + ")";
    }
}
let S = new NonTerminal("S");
let Stmt = new NonTerminal("Stmt");
let If = new NonTerminal("If");
let Expr = new NonTerminal("Expr");
let Other = new NonTerminal("Other");
/* (0) S->Stmt */
let p0 = new Production(0, S, [
    new SymbolWrapper(Stmt)
], undefined, undefined);
/* (1) Stmt->If<%(e)=>e[0]%> */
let p1 = new Production(1, Stmt, [
    new SymbolWrapper(If)
], undefined, (e) => e[0]);
/* (2) Stmt->Other<%(e)=>e[0]%> */
let p2 = new Production(2, Stmt, [
    new SymbolWrapper(Other)
], undefined, (e) => e[0]);
/* (3) If->ifExprStmt<%(e)=> new IfStmt(e)%> */
let p3 = new Production(3, If, [
    new SymbolWrapper("if"),
    new SymbolWrapper(Expr),
    new SymbolWrapper(Stmt)
], undefined, (e) => new IfStmt(e));
/* (4) If->ifExprStmtelseStmt<%(e)=> new IfStmt(e)%> */
let p4 = new Production(4, If, [
    new SymbolWrapper("if"),
    new SymbolWrapper(Expr),
    new SymbolWrapper(Stmt),
    new SymbolWrapper("else"),
    new SymbolWrapper(Stmt)
], undefined, (e) => new IfStmt(e));
/* (5) Expr->(Expr)<%(e)=>e[0]%> */
let p5 = new Production(5, Expr, [
    new SymbolWrapper("Expr")
], undefined, (e) => e[0]);
/* (6) Other->Other<%(e)=>e[0]%> */
let p6 = new Production(6, Other, [
    new SymbolWrapper("Other")
], undefined, (e) => e[0]);
S.prods = [p0];
Stmt.prods = [p1, p2];
If.prods = [p3, p4];
Expr.prods = [p5];
Other.prods = [p6];
let table = new ParsingTable();
table.put(0, Stmt, new Goto(1));
table.put(0, If, new Goto(2));
table.put(0, Other, new Goto(3));
table.put(0, "if", new Shift(4));
table.put(0, "Other", new Shift(5));
table.put(1, EOF, new Accept());
table.put(2, EOF, new Reduce(p1));
table.put(3, EOF, new Reduce(p2));
table.put(4, Expr, new Goto(6));
table.put(4, "Expr", new Shift(7));
table.put(5, EOF, new Reduce(p6));
table.put(6, Stmt, new Goto(8));
table.put(6, If, new Goto(9));
table.put(6, Other, new Goto(10));
table.put(6, "if", new Shift(11));
table.put(6, "Other", new Shift(12));
table.put(7, "if", new Reduce(p5));
table.put(7, "Other", new Reduce(p5));
table.put(8, EOF, new Reduce(p3));
table.put(8, "else", new Shift(13));
table.put(9, EOF, new Reduce(p1));
table.put(9, "else", new Reduce(p1));
table.put(10, EOF, new Reduce(p2));
table.put(10, "else", new Reduce(p2));
table.put(11, Expr, new Goto(14));
table.put(11, "Expr", new Shift(7));
table.put(12, EOF, new Reduce(p6));
table.put(12, "else", new Reduce(p6));
table.put(13, Stmt, new Goto(15));
table.put(13, If, new Goto(2));
table.put(13, Other, new Goto(3));
table.put(13, "if", new Shift(4));
table.put(13, "Other", new Shift(5));
table.put(14, Stmt, new Goto(16));
table.put(14, If, new Goto(9));
table.put(14, Other, new Goto(10));
table.put(14, "if", new Shift(11));
table.put(14, "Other", new Shift(12));
table.put(15, EOF, new Reduce(p4));
table.put(16, EOF, new Reduce(p3));
table.put(16, "else", new Shift(17));
table.put(17, Stmt, new Goto(18));
table.put(17, If, new Goto(9));
table.put(17, Other, new Goto(10));
table.put(17, "if", new Shift(11));
table.put(17, "Other", new Shift(12));
table.put(18, EOF, new Reduce(p4));
table.put(18, "else", new Reduce(p4));
import { LRParser } from "@parser-generator/core";
export let parser = new LRParser(table);
/*

#GRAMMAR
S -> Stmt ;
Stmt -> If | Other <% (e)=>e[0] %> ;
If ->
    'if' Expr Stmt |
    'if' Expr Stmt 'else' Stmt
    <% (e)=> new IfStmt(e) %>;
Expr -> 'Expr' <% (e)=>e[0] %>;
Other -> 'Other' <% (e)=>e[0] %>;

    'if' Expr Stmt {EOF}
    'if' Expr Stmt 'else' Stmt {EOF}

    'if' Expr 'if' Expr Stmt  {EOF}
    'if' Expr 'if' Expr Stmt  {'else'} 'else' Stmt {EOF}

    'if' Expr Stmt 'else' Stmt

*/
class Token {
    constructor(lexeme) {
        this.lexeme = lexeme;
    }
    key() {
        return this.lexeme;
    }
    toString() {
        return this.lexeme;
    }
}
class Lexer {
    constructor(lexemes) {
        this.i = 0;
        this.lexemes = lexemes;
    }
    peek() {
        return this.i >= this.lexemes.length ? new Token(EOF) : new Token(this.lexemes[this.i]);
    }
    next() {
        return this.i < this.lexemes.length ? new Token(this.lexemes[this.i++]) : new Token(EOF);
    }
}
let ast = parser.parse(new Lexer(["if", "Expr", "if", "Expr", "Other", "else", "Other"]));
console.log(ast.toString());
//(if Expr (if Expr Other else Other))
//# sourceMappingURL=test.js.map