arrayParser

arrayParser.js

const trim = (s) => s.trim();
const isDigit = (str) => /^\d+$/.test(str);

function makeObj({type,value}) {
    if(type === "array") return { type, child:[] }
    return {
        type : type, 
        value : value,
        child : []
    }
}

//tokenizer
function tokenizer(s) {
    const operators = ['[', ']', '{', '}', ',', ':'];
    let _tmpStr = "";
    const tokenArray = [];

    for(let i=0; i< s.length; i++) {
        let ch = s[i];

        if(ch === " ") continue;

        if(operators.indexOf(ch) > -1) {
            tokenArray.push(ch);
            continue;
        }

        _tmpStr = s.substr(i).match(/^('[^']+')|(\d+)|(null)/);
        if(_tmpStr) { 
            tokenArray.push(_tmpStr[0]);
            i += _tmpStr[0].length-1;
        } else {
            if(/'\w+.*/.test(s.substr(i))) {
                throw new Error("올바른 문자열형태가 아니네요");
            }

        }
    }
    return tokenArray;
}

//lexer
function lexer(a) {
    const lexerTokens = [];
    for (el of a) {
        if(el === "[") {
            lexerTokens.push(makeObj({ "type": "array" }))
        } else if (el === "]") {
            lexerTokens.push(makeObj({ "type": "arrayClose", "value": el }))
        } else if (/^'.*'$/.test(el)) {
            lexerTokens.push(makeObj({ "type": "string", "value": el }))
        } else if (/\d+/.test(el)) {
            lexerTokens.push(makeObj({ "type": "number", "value": el }))
        } else if (el === 'null') {
            lexerTokens.push(makeObj({ "type": "NULL", "value": el }))
        } else {
            //console.log("what is token", el);
        }
    }
    return lexerTokens;
}

//parser
function parser(a) {

    const arrayOpenCount = a.filter( ({type}) => type === "array").length;
    const arrayCloseCount = a.filter( ({type}) => type === "arrayClose").length;
    if(arrayOpenCount !== arrayCloseCount) throw new Error("배열이 잘 안닫힌거 같은데?");

    const result = {type:'root', child:[]};
    const _stack = [];
    for(el  of  a) {
        if(el.type  === "array") _stack.push(el);

        if(el.type === "number"  || el.type  === "string" || el.type === "NULL") {
            _stack[_stack.length-1].child.push(el);
        }

        if(el.type === "arrayClose") {
            const currentStack = _stack.pop();
            const _stackLength = _stack.length;
            if(_stackLength === 0)  result.child.push(currentStack)
            else _stack[_stack.length-1].child.push(currentStack);
        }
    }
    return result;
}

try {
    const d = "[[1,[2,[3]],'hello] world']";
    //const d =  "[1, [2,[3]],'hello', 'world', null]";
    const tokens = tokenizer(d);
    const lexerTokens = lexer(tokens);
    console.log('lexerTokens is ', lexerTokens);
    const resultData = parser(lexerTokens);
    console.log(JSON.stringify(resultData, null, 2));

} catch (err) {
    console.log("ERROR : ", err.message);
}