ludash/lib/formula.js

class Formula {
    constructor(_formula) {
        this.formula = "";
        this.watchers = [];
        this.ast = [];
        this.formula = _formula;
        this.compile();
    }
    compile() {
        const ast = this.formula.split(/([\+\-\*\/\(\)])/);
        this.ast = ast.filter((it) => it !== "");
        this.ast.forEach((char) => {
            if (this.isSymbol(char) || this.isStatic(char)) {
                return;
            }
            this.watchers.push(char.split(/[\.\[]/)[0]);
        });
    }
    isSymbol(char) {
        return /^[\+\-\*\/\(\)]{1}$/g.test(char);
    }
    isStatic(char) {
        return /[\"\']/.test(char) || /^\d+$/.test(char);
    }
    shouldUpdate(watcher) {
        return this.watchers.includes(watcher);
    }
    result(_context) {
        const ast = this.ast.map((char) => {
            if (this.isSymbol(char) || this.isStatic(char)) {
                return char;
            }
            return char.replace(/(^[\.\[]*)/, "_context.$1");
        });
        return eval(ast.join(""));
    }
    destroy() {
        this.formula = "";
        this.watchers = [];
        this.ast = [];
    }
}
export { Formula };