antlr4ng/dist/tree/pattern/ParseTreePatternMatcher.d.ts

Alternative JavaScript/TypeScript runtime for ANTLR4

import type { Lexer } from "../../Lexer.js";
import type { Parser } from "../../Parser.js";
import { Token } from "../../Token.js";
import { MultiMap } from "../../misc/MultiMap.js";
import type { ParseTree } from "../ParseTree.js";
import type { Chunk } from "./Chunk.js";
import { ParseTreeMatch } from "./ParseTreeMatch.js";
import { ParseTreePattern } from "./ParseTreePattern.js";
import { RuleTagToken } from "./RuleTagToken.js";
/**
 * A tree pattern matching mechanism for ANTLR {@link ParseTree}s.
 *
 * Patterns are strings of source input text with special tags representing
 * token or rule references such as:
 *
 * `<ID> = <expr>;`
 *
 * Given a pattern start rule such as `statement`, this object constructs
 * a {@link ParseTree} with placeholders for the `ID` and `expr`
 * subtree. Then the {@link #match} routines can compare an actual
 * {@link ParseTree} from a parse with this pattern. Tag `<ID>` matches
 * any `ID` token and tag `<expr>` references the result of the
 * `expr` rule (generally an instance of `ExprContext`.
 *
 * Pattern `x = 0;` is a similar pattern that matches the same pattern
 * except that it requires the identifier to be `x` and the expression to
 * be `0`.
 *
 * The {@link #matches} routines return `true` or `false` based
 * upon a match for the tree rooted at the parameter sent in. The
 * {@link #match} routines return a {@link ParseTreeMatch} object that
 * contains the parse tree, the parse tree pattern, and a map from tag name to
 * matched nodes (more below). A subtree that fails to match, returns with
 * {@link ParseTreeMatch#mismatchedNode} set to the first tree node that did not
 * match.
 *
 * For efficiency, you can compile a tree pattern in string form to a
 * {@link ParseTreePattern} object.
 *
 * See `TestParseTreeMatcher` for lots of examples.
 * {@link ParseTreePattern} has two static helper methods:
 * {@link ParseTreePattern.findAll} and {@link ParseTreePattern#match} that
 * are easy to use but not super efficient because they create new
 * {@link ParseTreePatternMatcher} objects each time and have to compile the
 * pattern in string form before using it.
 *
 * The lexer and parser that you pass into the {@link ParseTreePatternMatcher}
 * constructor are used to parse the pattern in string form. The lexer converts
 * the `<ID> = <expr>;` into a sequence of four tokens (assuming lexer
 * throws out whitespace or puts it on a hidden channel). Be aware that the
 * input stream is reset for the lexer (but not the parser; a
 * {@link ParserInterpreter} is created to parse the input.). Any user-defined
 * fields you have put into the lexer might get changed when this mechanism asks
 * it to scan the pattern string.
 *
 * Normally a parser does not accept token `<expr>` as a valid
 * `expr` but, from the parser passed in, we create a special version of
 * the underlying grammar representation (an {@link ATN}) that allows imaginary
 * tokens representing rules (`<expr>`) to match entire rules. We call
 * these *bypass alternatives*.
 *
 * Delimiters are `<` and `>`, with `\` as the escape string
 * by default, but you can set them to whatever you want using
 * {@link ParseTreePatternMatcher.setDelimiters}. You must escape both start and stop strings
 * `\<` and `\>`.
 */
export declare class ParseTreePatternMatcher {
    protected start: string;
    protected stop: string;
    protected escape: string;
    /**
     * This is the backing field for {@link #getLexer()}.
     */
    private readonly lexer;
    /**
     * This is the backing field for {@link #getParser()}.
     */
    private readonly parser;
    /**
     * Constructs a {@link ParseTreePatternMatcher} or from a {@link Lexer} and
     * {@link Parser} object. The lexer input stream is altered for tokenizing
     * the tree patterns. The parser is used as a convenient mechanism to get
     * the grammar name, plus token, rule names.
     */
    constructor(lexer: Lexer | null, parser: Parser | null);
    /**
     * Set the delimiters used for marking rule and token tags within concrete
     * syntax used by the tree pattern parser.
     *
     * @param start The start delimiter.
     * @param stop The stop delimiter.
     * @param escapeLeft The escape sequence to use for escaping a start or stop delimiter.
     *
     * @throws Error if `start` is `null` or empty.
     * @throws Error if `stop` is `null` or empty.
     */
    setDelimiters(start: string, stop: string, escapeLeft: string): void;
    /**
     * Does `pattern` matched as rule patternRuleIndex match tree? Pass in a
     *  compiled pattern instead of a string representation of a tree pattern.
     */
    matches(tree: ParseTree, pattern: ParseTreePattern): boolean;
    /** Does `pattern` matched as rule `patternRuleIndex` match `tree`? */
    matches(tree: ParseTree, pattern: string, patternRuleIndex: number): boolean;
    /**
     * Compare `pattern` matched against `tree` and return a
     * {@link ParseTreeMatch} object that contains the matched elements, or the
     * node at which the match failed. Pass in a compiled pattern instead of a
     * string representation of a tree pattern.
     */
    match(tree: ParseTree, pattern: ParseTreePattern): ParseTreeMatch;
    /**
     * Compare `pattern` matched as rule `patternRuleIndex` against
     * `tree` and return a {@link ParseTreeMatch} object that contains the
     * matched elements, or the node at which the match failed.
     */
    match(tree: ParseTree, pattern: string, patternRuleIndex: number): ParseTreeMatch;
    /**
     * For repeated use of a tree pattern, compile it to a
     * {@link ParseTreePattern} using this method.
     */
    compile(pattern: string, patternRuleIndex: number): ParseTreePattern;
    /**
     * Used to convert the tree pattern string into a series of tokens. The
     * input stream is reset.
     */
    getLexer(): Lexer | null;
    /**
     * Used to collect to the grammar file name, token names, rule names for
     * used to parse the pattern into a parse tree.
     */
    getParser(): Parser | null;
    tokenize(pattern: string): Token[];
    /**
     * Split `<ID> = <e:expr> ;` into 4 chunks for tokenizing by {@link #tokenize}.
     */
    split(pattern: string): Chunk[];
    /**
     * Recursively walk `tree` against `patternTree`, filling
     * `match.`{@link ParseTreeMatch#labels labels}.
     *
     * @returns the first node encountered in `tree` which does not match
     * a corresponding node in `patternTree`, or `null` if the match
     * was successful. The specific node returned depends on the matching
     * algorithm used by the implementation, and may be overridden.
     */
    protected matchImpl(tree: ParseTree, patternTree: ParseTree, labels: MultiMap<string, ParseTree>): ParseTree | undefined;
    /**
     * Is `t` `(expr <expr>)` subtree?
     */
    protected getRuleTagToken(t: ParseTree): RuleTagToken | undefined;
}