Compiler for the JSON Traversal Language.

chrome/tools/profile_reset/jtl_parser.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_TOOLS_PROFILE_RESET_JTL_PARSER_H_
+#define CHROME_TOOLS_PROFILE_RESET_JTL_PARSER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/values.h"
+
+// Parses text-based JTL source code into a stream of operation names, arguments
+// and separator kinds.
+class JtlParser {
+ public:
+  // Creates a new parser to parse |compacted_source_code|, which should already
+  // be stripped of all comments and whitespace (except inside string literals).
+  // Use RemoveCommentsAndAllWhitespace() to manufacture these arguments, also
+  // see its comments for a description of |newline_indices|.
+  JtlParser(const std::string& compacted_source_code,
+            const std::vector<size_t>& newline_indices);
+  ~JtlParser();
+
+  // Removes comments from |verbose_text| and compacts it into whitespace-free
+  // format (except inside string literals). Elements in |newline_indices| will
+  // be monotonically increasing and will refer to positions in |compacted_text|
+  // such that a new line has been removed before that position.
+  // Example:
+  //   verbose_text = "H e l l o // my\n"
+  //                  " dear \n"
+  //                  "\n"
+  //                  "world\" ! \""
+  //   compacted_text = "Hellodearworld\" ! \""
+  //                     01234567890123...
+  //   newline_indices = {5, 9, 9}
+  // Returns true on success, false if there were unmatched quotes in a line, in
+  // which case |error_line_number| will be set accordingly if it is non-NULL.
+  static bool RemoveCommentsAndAllWhitespace(
+      const std::string& verbose_text,
+      std::string* compacted_text,
+      std::vector<size_t>* newline_indices,
+      size_t* error_line_number);
+
+  // Returns true if the entire input has been successfully consumed. Note that
+  // even when this returns false, a subsequent call to ParseNextOperation()
+  // might still fail if the next operation cannot be parsed.
+  bool HasFinished();
+
+  // Fetches the |name| and the |argument_list| of the next operation, and also
+  // whether or not it |ends_the_sentence|, i.e. it is followed by the
+  // end-of-sentence separator.
+  // Returns false if there is a parsing error, in which case the values for the
+  // output parameters are undefined, and |this| parser shall no longer be used.
+  bool ParseNextOperation(std::string* name,
+                          base::ListValue* argument_list,
+                          bool* ends_the_sentence);
+
+  // Returns the compacted source code that was passed in to the constructor.
+  const std::string& compacted_source() const { return compacted_source_; }
+
+  // Returns at which line the character at position |compacted_index| in the
+  // |compacted_source()| was originally located.
+  size_t GetOriginalLineNumber(size_t compacted_index) const;
+
+  size_t GetLastLineNumber() const;
+  std::string GetLastContext() const;
+
+ private:
+  // Contains pre-compiled regular expressions and related state. Factored out
+  // to avoid this header depending on RE2 headers.
+  struct ParsingState;
+
+  std::string compacted_source_;
+  std::vector<size_t> newline_indices_;
+  scoped_ptr<ParsingState> state_;
+
+  DISALLOW_COPY_AND_ASSIGN(JtlParser);
+};
+
+#endif  // CHROME_TOOLS_PROFILE_RESET_JTL_PARSER_H_