--- /dev/null
+/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+ * Use of this file is governed by the BSD 3-clause license that
+ * can be found in the LICENSE.txt file in the project root.
+ */
+
+#pragma once
+
+namespace antlr4 {
+
+ /**
+ * Useful for rewriting out a buffered input token stream after doing some
+ * augmentation or other manipulations on it.
+ *
+ * <p>
+ * 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. :)</p>
+ *
+ * <p>
+ * 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 {@link TokenStream#index()} will return the same value before and
+ * after any {@link #getText()} call.</p>
+ *
+ * <p>
+ * 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.</p>
+ *
+ * <p>
+ * 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 {@code i} does not change the index values for tokens
+ * {@code i}+1..n-1.</p>
+ *
+ * <p>
+ * 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,</p>
+ *
+ * <pre>
+ * 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();
+ * </pre>
+ *
+ * <p>
+ * Then in the rules, you can execute (assuming rewriter is visible):</p>
+ *
+ * <pre>
+ * Token t,u;
+ * ...
+ * rewriter.insertAfter(t, "text to put after t");}
+ * rewriter.insertAfter(u, "text after u");}
+ * System.out.println(rewriter.getText());
+ * </pre>
+ *
+ * <p>
+ * 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:</p>
+ *
+ * <pre>
+ * 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"));
+ * </pre>
+ *
+ * <p>
+ * If you don't use named rewrite streams, a "default" stream is used as the
+ * first example shows.</p>
+ */
+ class ANTLR4CPP_PUBLIC TokenStreamRewriter {
+ public:
+ static const std::string DEFAULT_PROGRAM_NAME;
+#if __cplusplus >= 201703L
+ static constexpr size_t PROGRAM_INIT_SIZE = 100;
+ static constexpr size_t MIN_TOKEN_INDEX = 0;
+#else
+ enum : size_t {
+ PROGRAM_INIT_SIZE = 100,
+ MIN_TOKEN_INDEX = 0,
+ };
+#endif
+
+ TokenStreamRewriter(TokenStream *tokens);
+ virtual ~TokenStreamRewriter();
+
+ TokenStream *getTokenStream();
+
+ virtual void rollback(size_t instructionIndex);
+
+ /// Rollback the instruction stream for a program so that
+ /// the indicated instruction (via instructionIndex) is no
+ /// longer in the stream. UNTESTED!
+ virtual void rollback(const std::string &programName, size_t instructionIndex);
+
+ virtual void deleteProgram();
+
+ /// Reset the program so that no instructions exist.
+ virtual void deleteProgram(const std::string &programName);
+ virtual void insertAfter(Token *t, const std::string& text);
+ virtual void insertAfter(size_t index, const std::string& text);
+ virtual void insertAfter(const std::string &programName, Token *t, const std::string& text);
+ virtual void insertAfter(const std::string &programName, size_t index, const std::string& text);
+
+ virtual void insertBefore(Token *t, const std::string& text);
+ virtual void insertBefore(size_t index, const std::string& text);
+ virtual void insertBefore(const std::string &programName, Token *t, const std::string& text);
+ virtual void insertBefore(const std::string &programName, size_t index, const std::string& text);
+
+ virtual void replace(size_t index, const std::string& text);
+ virtual void replace(size_t from, size_t to, const std::string& text);
+ virtual void replace(Token *indexT, const std::string& text);
+ virtual void replace(Token *from, Token *to, const std::string& text);
+ virtual void replace(const std::string &programName, size_t from, size_t to, const std::string& text);
+ virtual void replace(const std::string &programName, Token *from, Token *to, const std::string& text);
+
+ virtual void Delete(size_t index);
+ virtual void Delete(size_t from, size_t to);
+ virtual void Delete(Token *indexT);
+ virtual void Delete(Token *from, Token *to);
+ virtual void Delete(const std::string &programName, size_t from, size_t to);
+ virtual void Delete(const std::string &programName, Token *from, Token *to);
+
+ virtual size_t getLastRewriteTokenIndex();
+
+ /// Return the text from the original tokens altered per the
+ /// instructions given to this rewriter.
+ virtual std::string getText();
+
+ /** Return the text from the original tokens altered per the
+ * instructions given to this rewriter in programName.
+ */
+ std::string getText(std::string programName);
+
+ /// Return the text associated with the tokens in the interval from the
+ /// original token stream but with the alterations given to this rewriter.
+ /// The interval refers to the indexes in the original token stream.
+ /// We do not alter the token stream in any way, so the indexes
+ /// and intervals are still consistent. Includes any operations done
+ /// to the first and last token in the interval. So, if you did an
+ /// insertBefore on the first token, you would get that insertion.
+ /// The same is true if you do an insertAfter the stop token.
+ virtual std::string getText(const misc::Interval &interval);
+
+ virtual std::string getText(const std::string &programName, const misc::Interval &interval);
+
+ protected:
+ class RewriteOperation {
+ public:
+ /// What index into rewrites List are we?
+ size_t index;
+ std::string text;
+
+ /// Token buffer index.
+ size_t instructionIndex;
+
+ RewriteOperation(TokenStreamRewriter *outerInstance, size_t index);
+ RewriteOperation(TokenStreamRewriter *outerInstance, size_t index, const std::string& text);
+ virtual ~RewriteOperation();
+
+ /// Execute the rewrite operation by possibly adding to the buffer.
+ /// Return the index of the next token to operate on.
+
+ virtual size_t execute(std::string *buf);
+ virtual std::string toString();
+
+ private:
+ TokenStreamRewriter *const outerInstance;
+ void InitializeInstanceFields();
+ };
+
+ class InsertBeforeOp : public RewriteOperation {
+ private:
+ TokenStreamRewriter *const outerInstance;
+
+ public:
+ InsertBeforeOp(TokenStreamRewriter *outerInstance, size_t index, const std::string& text);
+
+ virtual size_t execute(std::string *buf) override;
+ };
+
+ class ReplaceOp : public RewriteOperation {
+ private:
+ TokenStreamRewriter *const outerInstance;
+
+ public:
+ size_t lastIndex;
+
+ ReplaceOp(TokenStreamRewriter *outerInstance, size_t from, size_t to, const std::string& text);
+ virtual size_t execute(std::string *buf) override;
+ virtual std::string toString() override;
+
+ private:
+ void InitializeInstanceFields();
+ };
+
+ /// Our source stream
+ TokenStream *const tokens;
+
+ /// You may have multiple, named streams of rewrite operations.
+ /// I'm calling these things "programs."
+ /// Maps String (name) -> rewrite (List)
+ std::map<std::string, std::vector<RewriteOperation*>> _programs;
+
+ /// <summary>
+ /// Map String (program name) -> Integer index </summary>
+ std::map<std::string, size_t> _lastRewriteTokenIndexes;
+ virtual size_t getLastRewriteTokenIndex(const std::string &programName);
+ virtual void setLastRewriteTokenIndex(const std::string &programName, size_t i);
+ virtual std::vector<RewriteOperation*>& getProgram(const std::string &name);
+
+ /// <summary>
+ /// 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==null):
+ /// 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 null in list. Easier to walk list.
+ /// Later we can throw as we add to index -> 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.
+ /// </summary>
+ virtual std::unordered_map<size_t, RewriteOperation*> reduceToSingleOperationPerIndex(std::vector<RewriteOperation*> &rewrites);
+
+ virtual std::string catOpText(std::string *a, std::string *b);
+
+ /// Get all operations before an index of a particular kind.
+ template <typename T>
+ std::vector<T *> getKindOfOps(std::vector<RewriteOperation *> rewrites, size_t before) {
+ std::vector<T *> ops;
+ for (size_t i = 0; i < before && i < rewrites.size(); i++) {
+ T *op = dynamic_cast<T *>(rewrites[i]);
+ if (op == nullptr) { // ignore deleted or non matching entries
+ continue;
+ }
+ ops.push_back(op);
+ }
+ return ops;
+ }
+
+ private:
+ std::vector<RewriteOperation *>& initializeProgram(const std::string &name);
+
+ };
+
+} // namespace antlr4
projects / toc / blobdiff