SOURCE

//词法解析部分
let token = [];
let tokens = []
const start = (char) => {
    if (char === '1' || char === '2' || char === '3' || char === '4' || char === '5' || char === '6' || char === '7' || char === '8' || char === '9' || char === '0') {
        token.push(char)
        return inNumner
    }
    if (char === '+' || char === '-' || char === '*' || char === '/') {
        emmitToken(char, char); return start
    }
    if (char === ' ') {
        return start;
    }
    if (char === '\r' || char === '\n') {
        return start;
    }
    return  emmitToken(char, char)

}
const inNumner = (char) => {
    if (char === '1' || char === '2' || char === '3' || char === '4' || char === '5' || char === '6' || char === '7' || char === '8' || char === '9' || char === '0') {
        token.push(char)
        return inNumner
    } else {
        emmitToken("Number", token.join(""));
        token = [];
        return start(char);
    }
}
function emmitToken(type, value) {
    tokens.push({type,value});

    
}