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path: root/src/lstring.js
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"use strict";

const assert = require("assert");

const defs = require('./defs.js');

class TString {

    constructor(L, str) {
        this.realstring = str;
    }

    getstr() {
        return this.realstring;
    }

    tsslen() {
        return this.realstring.length;
    }

}

const luaS_eqlngstr = function(a, b) {
    assert(a instanceof TString);
    assert(b instanceof TString);
    return a == b || (a.realstring.length == b.realstring.length && a.realstring.join() == b.realstring.join());
};

/* converts strings (arrays) to a consistent map key */
const luaS_hash = function(str) {
    assert(str instanceof TString);
    return str.realstring.map(e => `${e}|`).join('');
};

/* variant that takes ownership of array */
const luaS_bless = function(L, str) {
    Object.freeze(str);
    return new TString(L, str);
};

/* makes a copy */
const luaS_new = function(L, str) {
    return luaS_bless(L, str.slice(0));
};

/* takes a js string */
const luaS_newliteral = function(L, str) {
    return luaS_bless(L, defs.to_luastring(str));
};

module.exports.luaS_eqlngstr   = luaS_eqlngstr;
module.exports.luaS_hash       = luaS_hash;
module.exports.luaS_bless      = luaS_bless;
module.exports.luaS_new        = luaS_new;
module.exports.luaS_newliteral = luaS_newliteral;
module.exports.TString         = TString;