enforestForStatement

enforester.js

    enforestForStatement() {
        this.matchKeyword("for");
        const condition = this.matchParens();
        const conditionEnforester = new Enforester(condition);
        if(conditionEnforester.isPunctuator(conditionEnforester.peek(), ";")) {
            conditionEnforester.advance();
            const test = conditionEnforester.isPunctuator(conditionEnforester.peek(), ";") ? null : conditionEnforester.enforestExpression();
            conditionEnforester.matchPunctuator(";");
            const update = conditionEnforester.terms.length === 0 ? null :  conditionEnforester.enforestExpression();
            const body = this.enforestStatement();
            return new AST.ForStatement({
                init: null,
                test,
                update,
                body
            });
        } else {
            // TODO
            const lookahead = conditionEnforester.peek();
            if(conditionEnforester.isKeyword(lookahead, "var") ||
               conditionEnforester.isKeyword(lookahead, "let") ||
               conditionEnforester.isKeyword(lookahead, "const")) {
                const init = conditionEnforester.enforestVariableDeclaration();
                const lookahead = conditionEnforester.peek();
                if(this.isKeyword(lookahead, "in") ||
                   this.isKeyword(lookahead, "of") ||
                   this.isKeyword(lookahead, "in")) {
                    conditionEnforester.advance();
                    const right = conditionEnforester.enforestExpression();
                    const body = this.enforestStatement();
                    return new AST.ForInStatement({
                        left: init,
                        right,
                        body
                    });
                } else if (this.isIdentifier(lookahead, "of")) {
                    conditionEnforester.advance();
                    const right = conditionEnforester.enforestExpression();
                    const body = this.enforestStatement();
                    return new AST.ForOfStatement({
                        left: init,
                        right,
                        body
                    });
                }
                conditionEnforester.matchPunctuator(";");
                if(conditionEnforester.isPunctuator(conditionEnforester.peek(), ";")) {
                    conditionEnforest.advance();
                    return new AST.ForStatement({
                        init,
                        test: null,
                        update: conditionEnforester.enforestExpression(),
                        body: this.enforestStatement()
                    });
                } else {
                    if(this.isKeyword(conditionEnforester.peek(1), "in") ||
                       this.isIdentifier(conditionEnforester.peek(1), "of")) {
                        const left = conditionEnforester.enforestBindingIdentifier();
                        const right = conditionEnforester.enforestExpression();
                        const body = this.enforestStatement();
                        if(this.isKeyword(conditionEnforester.advance(), "in")) {
                            return new AST.ForInStatement({ left, right, body });
                        } else {
                            return new AST.ForOfStatement({ left, right, body });
                        }
                    }
                }
            }
        }
    }