antlr4ts/TokenStreamRewriter.js

"use strict";
/*!
 * Copyright 2016 The ANTLR Project. All rights reserved.
 * Licensed under the BSD-3-Clause license. See LICENSE file in the project root for license information.
 */
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exports.RewriteOperation = exports.TokenStreamRewriter = void 0;
// ConvertTo-TS run at 2016-10-04T11:26:58.1768850-07:00
const Interval_1 = require("./misc/Interval");
const Decorators_1 = require("./Decorators");
const Token_1 = require("./Token");
/**
 * Useful for rewriting out a buffered input token stream after doing some
 * augmentation or other manipulations on it.
 *
 * You can insert stuff, replace, and delete chunks. Note that the operations
 * are done lazily--only if you convert the buffer to a {@link String} with
 * {@link TokenStream#getText()}. This is very efficient because you are not
 * moving data around all the time. As the buffer of tokens is converted to
 * strings, the {@link #getText()} method(s) scan the input token stream and
 * check to see if there is an operation at the current index. If so, the
 * operation is done and then normal {@link String} rendering continues on the
 * buffer. This is like having multiple Turing machine instruction streams
 * (programs) operating on a single input tape. :)
 *
 * This rewriter makes no modifications to the token stream. It does not ask the
 * stream to fill itself up nor does it advance the input cursor. The token
 * stream `TokenStream.index` will return the same value before and
 * after any {@link #getText()} call.
 *
 * The rewriter only works on tokens that you have in the buffer and ignores the
 * current input cursor. If you are buffering tokens on-demand, calling
 * {@link #getText()} halfway through the input will only do rewrites for those
 * tokens in the first half of the file.
 *
 * Since the operations are done lazily at {@link #getText}-time, operations do
 * not screw up the token index values. That is, an insert operation at token
 * index `i` does not change the index values for tokens
 * `i`+1..n-1.
 *
 * Because operations never actually alter the buffer, you may always get the
 * original token stream back without undoing anything. Since the instructions
 * are queued up, you can easily simulate transactions and roll back any changes
 * if there is an error just by removing instructions. For example,
 *
 * ```
 * CharStream input = new ANTLRFileStream("input");
 * TLexer lex = new TLexer(input);
 * CommonTokenStream tokens = new CommonTokenStream(lex);
 * T parser = new T(tokens);
 * TokenStreamRewriter rewriter = new TokenStreamRewriter(tokens);
 * parser.startRule();
 * ```
 *
 * Then in the rules, you can execute (assuming rewriter is visible):
 *
 * ```
 * Token t,u;
 * ...
 * rewriter.insertAfter(t, "text to put after t");}
 * rewriter.insertAfter(u, "text after u");}
 * System.out.println(rewriter.getText());
 * ```
 *
 * You can also have multiple "instruction streams" and get multiple rewrites
 * from a single pass over the input. Just name the instruction streams and use
 * that name again when printing the buffer. This could be useful for generating
 * a C file and also its header file--all from the same buffer:
 *
 * ```
 * rewriter.insertAfter("pass1", t, "text to put after t");}
 * rewriter.insertAfter("pass2", u, "text after u");}
 * System.out.println(rewriter.getText("pass1"));
 * System.out.println(rewriter.getText("pass2"));
 * ```
 *
 * If you don't use named rewrite streams, a "default" stream is used as the
 * first example shows.
 */
class TokenStreamRewriter {
    constructor(tokens) {
        this.tokens = tokens;
        this.programs = new Map();
        this.programs.set(TokenStreamRewriter.DEFAULT_PROGRAM_NAME, []);
        this.lastRewriteTokenIndexes = new Map();
    }
    getTokenStream() {
        return this.tokens;
    }
    rollback(instructionIndex, programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        let is = this.programs.get(programName);
        if (is != null) {
            this.programs.set(programName, is.slice(TokenStreamRewriter.MIN_TOKEN_INDEX, instructionIndex));
        }
    }
    deleteProgram(programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        this.rollback(TokenStreamRewriter.MIN_TOKEN_INDEX, programName);
    }
    insertAfter(tokenOrIndex, text, programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        let index;
        if (typeof tokenOrIndex === "number") {
            index = tokenOrIndex;
        }
        else {
            index = tokenOrIndex.tokenIndex;
        }
        // to insert after, just insert before next index (even if past end)
        let rewrites = this.getProgram(programName);
        let op = new InsertAfterOp(this.tokens, index, rewrites.length, text);
        rewrites.push(op);
    }
    insertBefore(tokenOrIndex, text, programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        let index;
        if (typeof tokenOrIndex === "number") {
            index = tokenOrIndex;
        }
        else {
            index = tokenOrIndex.tokenIndex;
        }
        let rewrites = this.getProgram(programName);
        let op = new InsertBeforeOp(this.tokens, index, rewrites.length, text);
        rewrites.push(op);
    }
    replaceSingle(index, text) {
        if (typeof index === "number") {
            this.replace(index, index, text);
        }
        else {
            this.replace(index, index, text);
        }
    }
    replace(from, to, text, programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        if (typeof from !== "number") {
            from = from.tokenIndex;
        }
        if (typeof to !== "number") {
            to = to.tokenIndex;
        }
        if (from > to || from < 0 || to < 0 || to >= this.tokens.size) {
            throw new RangeError(`replace: range invalid: ${from}..${to}(size=${this.tokens.size})`);
        }
        let rewrites = this.getProgram(programName);
        let op = new ReplaceOp(this.tokens, from, to, rewrites.length, text);
        rewrites.push(op);
    }
    delete(from, to, programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        if (to === undefined) {
            to = from;
        }
        if (typeof from === "number") {
            this.replace(from, to, "", programName);
        }
        else {
            this.replace(from, to, "", programName);
        }
    }
    getLastRewriteTokenIndex(programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        let I = this.lastRewriteTokenIndexes.get(programName);
        if (I == null) {
            return -1;
        }
        return I;
    }
    setLastRewriteTokenIndex(programName, i) {
        this.lastRewriteTokenIndexes.set(programName, i);
    }
    getProgram(name) {
        let is = this.programs.get(name);
        if (is == null) {
            is = this.initializeProgram(name);
        }
        return is;
    }
    initializeProgram(name) {
        let is = [];
        this.programs.set(name, is);
        return is;
    }
    getText(intervalOrProgram, programName = TokenStreamRewriter.DEFAULT_PROGRAM_NAME) {
        let interval;
        if (intervalOrProgram instanceof Interval_1.Interval) {
            interval = intervalOrProgram;
        }
        else {
            interval = Interval_1.Interval.of(0, this.tokens.size - 1);
        }
        if (typeof intervalOrProgram === "string") {
            programName = intervalOrProgram;
        }
        let rewrites = this.programs.get(programName);
        let start = interval.a;
        let stop = interval.b;
        // ensure start/end are in range
        if (stop > this.tokens.size - 1) {
            stop = this.tokens.size - 1;
        }
        if (start < 0) {
            start = 0;
        }
        if (rewrites == null || rewrites.length === 0) {
            return this.tokens.getText(interval); // no instructions to execute
        }
        let buf = [];
        // First, optimize instruction stream
        let indexToOp = this.reduceToSingleOperationPerIndex(rewrites);
        // Walk buffer, executing instructions and emitting tokens
        let i = start;
        while (i <= stop && i < this.tokens.size) {
            let op = indexToOp.get(i);
            indexToOp.delete(i); // remove so any left have index size-1
            let t = this.tokens.get(i);
            if (op == null) {
                // no operation at that index, just dump token
                if (t.type !== Token_1.Token.EOF) {
                    buf.push(String(t.text));
                }
                i++; // move to next token
            }
            else {
                i = op.execute(buf); // execute operation and skip
            }
        }
        // include stuff after end if it's last index in buffer
        // So, if they did an insertAfter(lastValidIndex, "foo"), include
        // foo if end==lastValidIndex.
        if (stop === this.tokens.size - 1) {
            // Scan any remaining operations after last token
            // should be included (they will be inserts).
            for (let op of indexToOp.values()) {
                if (op.index >= this.tokens.size - 1) {
                    buf.push(op.text.toString());
                }
            }
        }
        return buf.join("");
    }
    /** We need to combine operations and report invalid operations (like
     *  overlapping replaces that are not completed nested). Inserts to
     *  same index need to be combined etc...  Here are the cases:
     *
     *  I.i.u I.j.v								leave alone, nonoverlapping
     *  I.i.u I.i.v								combine: Iivu
     *
     *  R.i-j.u R.x-y.v	| i-j in x-y			delete first R
     *  R.i-j.u R.i-j.v							delete first R
     *  R.i-j.u R.x-y.v	| x-y in i-j			ERROR
     *  R.i-j.u R.x-y.v	| boundaries overlap	ERROR
     *
     *  Delete special case of replace (text==undefined):
     *  D.i-j.u D.x-y.v	| boundaries overlap	combine to max(min)..max(right)
     *
     *  I.i.u R.x-y.v | i in (x+1)-y			delete I (since insert before
     * 											we're not deleting i)
     *  I.i.u R.x-y.v | i not in (x+1)-y		leave alone, nonoverlapping
     *  R.x-y.v I.i.u | i in x-y				ERROR
     *  R.x-y.v I.x.u 							R.x-y.uv (combine, delete I)
     *  R.x-y.v I.i.u | i not in x-y			leave alone, nonoverlapping
     *
     *  I.i.u = insert u before op @ index i
     *  R.x-y.u = replace x-y indexed tokens with u
     *
     *  First we need to examine replaces. For any replace op:
     *
     * 		1. wipe out any insertions before op within that range.
     * 		2. Drop any replace op before that is contained completely within
     * 	 that range.
     * 		3. Throw exception upon boundary overlap with any previous replace.
     *
     *  Then we can deal with inserts:
     *
     * 		1. for any inserts to same index, combine even if not adjacent.
     * 		2. for any prior replace with same left boundary, combine this
     * 	 insert with replace and delete this replace.
     * 		3. throw exception if index in same range as previous replace
     *
     *  Don't actually delete; make op undefined in list. Easier to walk list.
     *  Later we can throw as we add to index &rarr; op map.
     *
     *  Note that I.2 R.2-2 will wipe out I.2 even though, technically, the
     *  inserted stuff would be before the replace range. But, if you
     *  add tokens in front of a method body '{' and then delete the method
     *  body, I think the stuff before the '{' you added should disappear too.
     *
     *  Return a map from token index to operation.
     */
    reduceToSingleOperationPerIndex(rewrites) {
        // console.log(`rewrites=[${Utils.join(rewrites, ", ")}]`);
        // WALK REPLACES
        for (let i = 0; i < rewrites.length; i++) {
            let op = rewrites[i];
            if (op == null) {
                continue;
            }
            if (!(op instanceof ReplaceOp)) {
                continue;
            }
            let rop = op;
            // Wipe prior inserts within range
            let inserts = this.getKindOfOps(rewrites, InsertBeforeOp, i);
            for (let iop of inserts) {
                if (iop.index === rop.index) {
                    // E.g., insert before 2, delete 2..2; update replace
                    // text to include insert before, kill insert
                    rewrites[iop.instructionIndex] = undefined;
                    rop.text = iop.text.toString() + (rop.text != null ? rop.text.toString() : "");
                }
                else if (iop.index > rop.index && iop.index <= rop.lastIndex) {
                    // delete insert as it's a no-op.
                    rewrites[iop.instructionIndex] = undefined;
                }
            }
            // Drop any prior replaces contained within
            let prevReplaces = this.getKindOfOps(rewrites, ReplaceOp, i);
            for (let prevRop of prevReplaces) {
                if (prevRop.index >= rop.index && prevRop.lastIndex <= rop.lastIndex) {
                    // delete replace as it's a no-op.
                    rewrites[prevRop.instructionIndex] = undefined;
                    continue;
                }
                // throw exception unless disjoint or identical
                let disjoint = prevRop.lastIndex < rop.index || prevRop.index > rop.lastIndex;
                // Delete special case of replace (text==null):
                // D.i-j.u D.x-y.v	| boundaries overlap	combine to max(min)..max(right)
                if (prevRop.text == null && rop.text == null && !disjoint) {
                    // console.log(`overlapping deletes: ${prevRop}, ${rop}`);
                    rewrites[prevRop.instructionIndex] = undefined; // kill first delete
                    rop.index = Math.min(prevRop.index, rop.index);
                    rop.lastIndex = Math.max(prevRop.lastIndex, rop.lastIndex);
                    // console.log(`new rop ${rop}`);
                }
                else if (!disjoint) {
                    throw new Error(`replace op boundaries of ${rop} overlap with previous ${prevRop}`);
                }
            }
        }
        // WALK INSERTS
        for (let i = 0; i < rewrites.length; i++) {
            let op = rewrites[i];
            if (op == null) {
                continue;
            }
            if (!(op instanceof InsertBeforeOp)) {
                continue;
            }
            let iop = op;
            // combine current insert with prior if any at same index
            let prevInserts = this.getKindOfOps(rewrites, InsertBeforeOp, i);
            for (let prevIop of prevInserts) {
                if (prevIop.index === iop.index) {
                    if (prevIop instanceof InsertAfterOp) {
                        iop.text = this.catOpText(prevIop.text, iop.text);
                        rewrites[prevIop.instructionIndex] = undefined;
                    }
                    else if (prevIop instanceof InsertBeforeOp) { // combine objects
                        // convert to strings...we're in process of toString'ing
                        // whole token buffer so no lazy eval issue with any templates
                        iop.text = this.catOpText(iop.text, prevIop.text);
                        // delete redundant prior insert
                        rewrites[prevIop.instructionIndex] = undefined;
                    }
                }
            }
            // look for replaces where iop.index is in range; error
            let prevReplaces = this.getKindOfOps(rewrites, ReplaceOp, i);
            for (let rop of prevReplaces) {
                if (iop.index === rop.index) {
                    rop.text = this.catOpText(iop.text, rop.text);
                    rewrites[i] = undefined; // delete current insert
                    continue;
                }
                if (iop.index >= rop.index && iop.index <= rop.lastIndex) {
                    throw new Error(`insert op ${iop} within boundaries of previous ${rop}`);
                }
            }
        }
        // console.log(`rewrites after=[${Utils.join(rewrites, ", ")}]`);
        let m = new Map();
        for (let op of rewrites) {
            if (op == null) {
                // ignore deleted ops
                continue;
            }
            if (m.get(op.index) != null) {
                throw new Error("should only be one op per index");
            }
            m.set(op.index, op);
        }
        // console.log(`index to op: ${m}`);
        return m;
    }
    catOpText(a, b) {
        let x = "";
        let y = "";
        if (a != null) {
            x = a.toString();
        }
        if (b != null) {
            y = b.toString();
        }
        return x + y;
    }
    /** Get all operations before an index of a particular kind */
    getKindOfOps(rewrites, kind, before) {
        let ops = [];
        for (let i = 0; i < before && i < rewrites.length; i++) {
            let op = rewrites[i];
            if (op == null) {
                // ignore deleted
                continue;
            }
            if (op instanceof kind) {
                ops.push(op);
            }
        }
        return ops;
    }
}
exports.TokenStreamRewriter = TokenStreamRewriter;
TokenStreamRewriter.DEFAULT_PROGRAM_NAME = "default";
TokenStreamRewriter.PROGRAM_INIT_SIZE = 100;
TokenStreamRewriter.MIN_TOKEN_INDEX = 0;
// Define the rewrite operation hierarchy
class RewriteOperation {
    constructor(tokens, index, instructionIndex, text) {
        this.tokens = tokens;
        this.instructionIndex = instructionIndex;
        this.index = index;
        this.text = text === undefined ? "" : text;
    }
    /** Execute the rewrite operation by possibly adding to the buffer.
     *  Return the index of the next token to operate on.
     */
    execute(buf) {
        return this.index;
    }
    toString() {
        let opName = this.constructor.name;
        let $index = opName.indexOf("$");
        opName = opName.substring($index + 1, opName.length);
        return "<" + opName + "@" + this.tokens.get(this.index) +
            ":\"" + this.text + "\">";
    }
}
__decorate([
    Decorators_1.Override
], RewriteOperation.prototype, "toString", null);
exports.RewriteOperation = RewriteOperation;
class InsertBeforeOp extends RewriteOperation {
    constructor(tokens, index, instructionIndex, text) {
        super(tokens, index, instructionIndex, text);
    }
    execute(buf) {
        buf.push(this.text.toString());
        if (this.tokens.get(this.index).type !== Token_1.Token.EOF) {
            buf.push(String(this.tokens.get(this.index).text));
        }
        return this.index + 1;
    }
}
__decorate([
    Decorators_1.Override
], InsertBeforeOp.prototype, "execute", null);
/** Distinguish between insert after/before to do the "insert afters"
 *  first and then the "insert befores" at same index. Implementation
 *  of "insert after" is "insert before index+1".
 */
class InsertAfterOp extends InsertBeforeOp {
    constructor(tokens, index, instructionIndex, text) {
        super(tokens, index + 1, instructionIndex, text); // insert after is insert before index+1
    }
}
/** I'm going to try replacing range from x..y with (y-x)+1 ReplaceOp
 *  instructions.
 */
class ReplaceOp extends RewriteOperation {
    constructor(tokens, from, to, instructionIndex, text) {
        super(tokens, from, instructionIndex, text);
        this.lastIndex = to;
    }
    execute(buf) {
        if (this.text != null) {
            buf.push(this.text.toString());
        }
        return this.lastIndex + 1;
    }
    toString() {
        if (this.text == null) {
            return "<DeleteOp@" + this.tokens.get(this.index) +
                ".." + this.tokens.get(this.lastIndex) + ">";
        }
        return "<ReplaceOp@" + this.tokens.get(this.index) +
            ".." + this.tokens.get(this.lastIndex) + ":\"" + this.text + "\">";
    }
}
__decorate([
    Decorators_1.Override
], ReplaceOp.prototype, "execute", null);
__decorate([
    Decorators_1.Override
], ReplaceOp.prototype, "toString", null);
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