clang-tools-extra/clang-include-fixer/FuzzySymbolIndex.h

   1 //===--- FuzzySymbolIndex.h - Lookup symbols for autocomplete ---*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_CLANG_TOOLS_EXTRA_INCLUDE_FIXER_FUZZY_SYMBOL_INDEX_H
  10 #define LLVM_CLANG_TOOLS_EXTRA_INCLUDE_FIXER_FUZZY_SYMBOL_INDEX_H
  11
  12 #include "SymbolIndex.h"
  13 #include "find-all-symbols/SymbolInfo.h"
  14 #include "llvm/ADT/SmallString.h"
  15 #include "llvm/ADT/StringRef.h"
  16 #include "llvm/Support/Error.h"
  17 #include <string>
  18 #include <vector>
  19
  20 namespace clang {
  21 namespace include_fixer {
  22
  23 // A FuzzySymbolIndex retrieves top-level symbols matching a query string.
  24 //
  25 // It refines the contract of SymbolIndex::search to do fuzzy matching:
  26 // - symbol names are tokenized: "unique ptr", "string ref".
  27 // - query must match prefixes of symbol tokens: [upt]
  28 // - if the query has multiple tokens, splits must match: [StR], not [STr].
  29 // Helpers for tokenization and regex matching are provided.
  30 //
  31 // Implementations may choose to truncate results, refuse short queries, etc.
  32 class FuzzySymbolIndex : public SymbolIndex {
  33 public:
  34   // Loads the specified clang-include-fixer database and returns an index serving it.
  35   static llvm::Expected<std::unique_ptr<FuzzySymbolIndex>>
  36   createFromYAML(llvm::StringRef File);
  37
  38   // Helpers for implementing indexes:
  39
  40   // Transforms a symbol name or query into a sequence of tokens.
  41   // - URLHandlerCallback --> [url, handler, callback]
  42   // - snake_case11 --> [snake, case, 11]
  43   // - _WTF$ --> [wtf]
  44   static std::vector<std::string> tokenize(llvm::StringRef Text);
  45
  46   // Transforms query tokens into an unanchored regexp to match symbol tokens.
  47   // - [fe f] --> /f(\w* )?e\w* f/, matches [fee fie foe].
  48   static std::string queryRegexp(const std::vector<std::string> &Tokens);
  49 };
  50
  51 } // namespace include_fixer
  52 } // namespace clang
  53
  54 #endif // LLVM_CLANG_TOOLS_EXTRA_INCLUDE_FIXER_FUZZY_SYMBOL_INDEX_H