[clangd] NFC: Simplify code, enforce LLVM Coding Standards

[kbobyrev]

Summary

For consistency, functional-style code pieces are replaced with their simple counterparts to improve readability.

Also, file headers are fixed to comply with LLVM Coding Standards.

static member of anonymous namespace is not marked static anymore, because it is redundant.

clang-tools-extra/clangd/index/dex/Dex.h

 //===--- Dex.h - Dex Symbol Index Implementation ----------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// This defines Dex - a symbol index implementation based on query iterators
-// over symbol tokens, such as fuzzy matching trigrams, scopes, types, etc.
-// While consuming more memory and having longer build stage due to
-// preprocessing, Dex will have substantially lower latency. It will also allow
-// efficient symbol searching which is crucial for operations like code
-// completion, and can be very important for a number of different code
-// transformations which will be eventually supported by Clangd.
-//
+///
+/// \file
+/// This defines Dex - a symbol index implementation based on query iterators
+/// over symbol tokens, such as fuzzy matching trigrams, scopes, types, etc.
+/// While consuming more memory and having longer build stage due to
+/// preprocessing, Dex will have substantially lower latency. It will also allow
+/// efficient symbol searching which is crucial for operations like code
+/// completion, and can be very important for a number of different code
+/// transformations which will be eventually supported by Clangd.
+///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_DEX_DEX_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_DEX_DEX_H
 
 #include "Iterator.h"
 #include "PostingList.h"
 #include "Token.h"

clang-tools-extra/clangd/index/dex/Dex.cpp

 
 namespace clang {
 namespace clangd {
 namespace dex {
 
 namespace {
 
 // Mark symbols which are can be used for code completion.
-static const Token RestrictedForCodeCompletion =
+const Token RestrictedForCodeCompletion =
     Token(Token::Kind::Sentinel, "Restricted For Code Completion");
 
 // Returns the tokens which are given symbol's characteristics. Currently, the
 // generated tokens only contain fuzzy matching trigrams and symbol's scope,
 // but in the future this will also return path proximity tokens and other
 // types of tokens such as symbol type (if applicable).
 // Returns the tokens which are given symbols's characteristics. For example,
 // trigrams and scopes.

clang-tools-extra/clangd/index/dex/Iterator.h

 //===--- Iterator.h - Query Symbol Retrieval --------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// Symbol index queries consist of specific requirements for the requested
-// symbol, such as high fuzzy matching score, scope, type etc. The lists of all
-// symbols matching some criteria (e.g. belonging to "clang::clangd::" scope)
-// are expressed in a form of Search Tokens which are stored in the inverted
-// index. Inverted index maps these tokens to the posting lists - sorted (by
-// symbol quality) sequences of symbol IDs matching the token, e.g. scope token
-// "clangd::clangd::" is mapped to the list of IDs of all symbols which are
-// declared in this namespace. Search queries are build from a set of
-// requirements which can be combined with each other forming the query trees.
-// The leafs of such trees are posting lists, and the nodes are operations on
-// these posting lists, e.g. intersection or union. Efficient processing of
-// these multi-level queries is handled by Iterators. Iterators advance through
-// all leaf posting lists producing the result of search query, which preserves
-// the sorted order of IDs. Having the resulting IDs sorted is important,
-// because it allows receiving a certain number of the most valuable items (e.g.
-// symbols with highest quality which was the sorting key in the first place)
-// without processing all items with requested properties (this might not be
-// computationally effective if search request is not very restrictive).
+///
+/// \file
+/// Symbol index queries consist of specific requirements for the requested
+/// symbol, such as high fuzzy matching score, scope, type etc. The lists of all
+/// symbols matching some criteria (e.g. belonging to "clang::clangd::" scope)
+/// are expressed in a form of Search Tokens which are stored in the inverted
+/// index. Inverted index maps these tokens to the posting lists - sorted (by
+/// symbol quality) sequences of symbol IDs matching the token, e.g. scope token
+/// "clangd::clangd::" is mapped to the list of IDs of all symbols which are
+/// declared in this namespace. Search queries are build from a set of
+/// requirements which can be combined with each other forming the query trees.
+/// The leafs of such trees are posting lists, and the nodes are operations on
+/// these posting lists, e.g. intersection or union. Efficient processing of
+/// these multi-level queries is handled by Iterators. Iterators advance through
+/// all leaf posting lists producing the result of search query, which preserves
+/// the sorted order of IDs. Having the resulting IDs sorted is important,
+/// because it allows receiving a certain number of the most valuable items
+/// (e.g. symbols with highest quality which was the sorting key in the first
+/// place) without processing all items with requested properties (this might
+/// not be computationally effective if search request is not very restrictive).
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_DEX_ITERATOR_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_INDEX_DEX_ITERATOR_H
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/raw_ostream.h"

clang-tools-extra/clangd/index/dex/Iterator.cpp

void advanceTo(DocID ID) override {
     Children.front()->advanceTo(ID);
     sync();
   }
 
   DocID peek() const override { return Children.front()->peek(); }
 
   float consume() override {
     assert(!reachedEnd() && "AND iterator can't consume() at the end.");
-    return std::accumulate(
-        begin(Children), end(Children), DEFAULT_BOOST_SCORE,
-        [&](float Current, const std::unique_ptr<Iterator> &Child) {
-          return Current * Child->consume();
-        });
+    float Boost = DEFAULT_BOOST_SCORE;
+    for (const auto &Child : Children)
+      Boost *= Child->consume();
+    return Boost;
   }
 
   size_t estimateSize() const override {
     return Children.front()->estimateSize();
   }
 
 private:
   llvm::raw_ostream &dump(llvm::raw_ostream &OS) const override {

 public:
   explicit OrIterator(std::vector<std::unique_ptr<Iterator>> AllChildren)
       : Children(std::move(AllChildren)) {
     assert(!Children.empty() && "OR iterator should have at least one child.");
   }
 
   /// Returns true if all children are exhausted.
   bool reachedEnd() const override {
-    return std::all_of(begin(Children), end(Children),
-                       [](const std::unique_ptr<Iterator> &Child) {
-                         return Child->reachedEnd();
-                       });
+    for (const auto &Child : Children)
+      if (!Child->reachedEnd())
+        return false;
+    return true;
   }
 
   /// Moves each child pointing to the smallest DocID to the next item.
   void advance() override {
     assert(!reachedEnd() && "OR iterator can't advance() at the end.");
     const auto SmallestID = peek();
     for (const auto &Child : Children)
       if (!Child->reachedEnd() && Child->peek() == SmallestID)
DocID peek() const override {
     return Result;
   }
 
   // Returns the maximum boosting score among all Children when iterator is not
   // exhausted and points to the given ID, DEFAULT_BOOST_SCORE otherwise.
   float consume() override {
     assert(!reachedEnd() && "OR iterator can't consume() at the end.");
     const DocID ID = peek();
-    return std::accumulate(
-        begin(Children), end(Children), DEFAULT_BOOST_SCORE,
-        [&](float Boost, const std::unique_ptr<Iterator> &Child) {
-          return (!Child->reachedEnd() && Child->peek() == ID)
-                     ? std::max(Boost, Child->consume())
-                     : Boost;
-        });
+    float Boost = DEFAULT_BOOST_SCORE;
+    for (const auto &Child : Children)
+      if (!Child->reachedEnd() && Child->peek() == ID)
+        Boost = std::max(Boost, Child->consume());
+    return Boost;
   }
 
   size_t estimateSize() const override {
-    return std::accumulate(
-        begin(Children), end(Children), Children.front()->estimateSize(),
-        [&](size_t Current, const std::unique_ptr<Iterator> &Child) {
-          return std::max(Current, Child->estimateSize());
-        });
+    size_t Size = 0;
+    for (const auto &Child : Children)
+      Size = std::max(Size, Child->estimateSize());
+    return Size;
   }
 
 private:
   llvm::raw_ostream &dump(llvm::raw_ostream &OS) const override {
     OS << "(| ";
     auto Separator = "";
     for (const auto &Child : Children) {
       OS << Separator << *Child;

clang-tools-extra/clangd/index/dex/Token.h

 //===--- Token.h - Symbol Search primitive ----------------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// Token objects represent a characteristic of a symbol, which can be used to
-// perform efficient search. Tokens are keys for inverted index which are mapped
-// to the corresponding posting lists.
-//
-// The symbol std::cout might have the tokens:
-// * Scope "std::"
-// * Trigram "cou"
-// * Trigram "out"
-// * Type "std::ostream"
-//
+///
+/// \file
+/// Token objects represent a characteristic of a symbol, which can be used to
+/// perform efficient search. Tokens are keys for inverted index which are
+/// mapped to the corresponding posting lists.
+///
+/// The symbol std::cout might have the tokens:
+/// * Scope "std::"
+/// * Trigram "cou"
+/// * Trigram "out"
+/// * Type "std::ostream"
+///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_DEX_TOKEN_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_DEX_TOKEN_H
 
 #include "index/Index.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/raw_ostream.h"

clang-tools-extra/clangd/index/dex/Trigram.h

 //===--- Trigram.h - Trigram generation for Fuzzy Matching ------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
-//
-// Trigrams are attributes of the symbol unqualified name used to effectively
-// extract symbols which can be fuzzy-matched given user query from the inverted
-// index. To match query with the extracted set of trigrams Q, the set of
-// generated trigrams T for identifier (unqualified symbol name) should contain
-// all items of Q, i.e. Q ⊆ T.
-//
-// Trigram sets extracted from unqualified name and from query are different:
-// the set of query trigrams only contains consecutive sequences of three
-// characters (which is only a subset of all trigrams generated for an
-// identifier).
-//
+///
+/// \file
+/// Trigrams are attributes of the symbol unqualified name used to effectively
+/// extract symbols which can be fuzzy-matched given user query from the
+/// inverted index. To match query with the extracted set of trigrams Q, the set
+/// of generated trigrams T for identifier (unqualified symbol name) should
+/// contain all items of Q, i.e. Q ⊆ T.
+///
+/// Trigram sets extracted from unqualified name and from query are different:
+/// the set of query trigrams only contains consecutive sequences of three
+/// characters (which is only a subset of all trigrams generated for an
+/// identifier).
+///
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_DEX_TRIGRAM_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_DEX_TRIGRAM_H
 
 #include "Token.h"
 
 #include <string>