helper.ts

/**
 * Copyright (c) 2017-2021 mol* contributors, licensed under MIT, See LICENSE file for more info.
 *
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 * @author Panagiotis Tourlas <panagiot_tourlov@hotmail.com>
 * @author Koya Sakuma
 */
// import * as Q from 'parsimmon';
import * as P from '../../mol-util/monadic-parser';
import { MolScriptBuilder } from '../../mol-script/language/builder';
const B = MolScriptBuilder;
import { Expression } from '../language/expression';
import { KeywordDict, PropertyDict, FunctionDict, OperatorList } from './types';

export function escapeRegExp(s: String) {
    return String(s).replace(/[\\^$*+?.()|[\]{}]/g, '\\$&');
}

// Takes a parser for the prefix operator, and a parser for the base thing being
// parsed, and parses as many occurrences as possible of the prefix operator.
// Note that the parser is created using `P.lazy` because it's recursive. It's
// valid for there to be zero occurrences of the prefix operator.
export function prefix(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    const parser: P.MonadicParser<any> = P.MonadicParser.lazy(() => {
        return P.MonadicParser.seq(opParser, parser)
            .map(x => mapFn(...x))
            .or(nextParser);
    });
    return parser;
}

// Ideally this function would be just like `PREFIX` but reordered like
// `P.seq(parser, opParser).or(nextParser)`, but that doesn't work. The
// reason for that is that Parsimmon will get stuck in infinite recursion, since
// the very first rule. Inside `parser` is to match parser again. Alternatively,
// you might think to try `nextParser.or(P.seq(parser, opParser))`, but
// that won't work either because in a call to `.or` (aka `P.alt`), Parsimmon
// takes the first possible match, even if subsequent matches are longer, so the
// parser will never actually look far enough ahead to see the postfix
// operators.
export function postfix(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    // Because we can't use recursion like stated above, we just match a flat list
    // of as many occurrences of the postfix operator as possible, then use
    // `.reduce` to manually nest the list.
    //
    // Example:
    //
    // INPUT  :: "4!!!"
    // PARSE  :: [4, "factorial", "factorial", "factorial"]
    // REDUCE :: ["factorial", ["factorial", ["factorial", 4]]]
    return P.MonadicParser.seqMap(/* no seqMap() in monadic-parser.ts, any suitable replacement? */
        nextParser,
        opParser.many(),
        (x: any, suffixes: any) =>
            suffixes.reduce((acc: any, x: any) => {
                return mapFn(x, acc);
            }, x)
    );
}

// Takes a parser for all the operators at this precedence level, and a parser
// that parsers everything at the next precedence level, and returns a parser
// that parses as many binary operations as possible, associating them to the
// right. (e.g. 1^2^3 is 1^(2^3) not (1^2)^3)
export function binaryRight(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    const parser: P.MonadicParser<any> = P.MonadicParser.lazy(() =>
        nextParser.chain(next =>
            P.MonadicParser.seq(
                opParser,
                P.MonadicParser.of(next),