//===-- StringExtras.cpp - Implement the StringExtras header --------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file implements the StringExtras.h header

//

//===----------------------------------------------------------------------===//

#include "llvm/ADT/StringExtras.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/Support/raw_ostream.h"

#include <cctype>

using namespace llvm;

/// StrInStrNoCase - Portable version of strcasestr.  Locates the first

/// occurrence of string 's1' in string 's2', ignoring case.  Returns

/// the offset of s2 in s1 or npos if s2 cannot be found.

StringRef::size_type llvm::StrInStrNoCase(StringRef s1, StringRef s2) {

  size_t N = s2.size(), M = s1.size();

  if (N > M)

    return StringRef::npos;

  for (size_t i = 0, e = M - N + 1; i != e; ++i)

    if (s1.substr(i, N).equals_lower(s2))

      return i;

  return StringRef::npos;

}

/// getToken - This function extracts one token from source, ignoring any

/// leading characters that appear in the Delimiters string, and ending the

/// token at any of the characters that appear in the Delimiters string.  If

/// there are no tokens in the source string, an empty string is returned.

/// The function returns a pair containing the extracted token and the

/// remaining tail string.

std::pair<StringRef, StringRef> llvm::getToken(StringRef Source,

                                               StringRef Delimiters) {

  // Figure out where the token starts.

  StringRef::size_type Start = Source.find_first_not_of(Delimiters);

  // Find the next occurrence of the delimiter.

  StringRef::size_type End = Source.find_first_of(Delimiters, Start);

  return std::make_pair(Source.slice(Start, End), Source.substr(End));

}

/// SplitString - Split up the specified string according to the specified

/// delimiters, appending the result fragments to the output list.

void llvm::SplitString(StringRef Source,

                       SmallVectorImpl<StringRef> &OutFragments,

                       StringRef Delimiters) {

  std::pair<StringRef, StringRef> S = getToken(Source, Delimiters);

  while (!S.first.empty()) {

    OutFragments.push_back(S.first);

    S = getToken(S.second, Delimiters);

  }

}

void llvm::printEscapedString(StringRef Name, raw_ostream &Out) {

  for (unsigned i = 0, e = Name.size(); i != e; ++i) {

    unsigned char C = Name[i];

    if (C == '\\')

      Out << '\\' << C;

    else if (isPrint(C) && C != '"')

      Out << C;

    else

      Out << '\\' << hexdigit(C >> 4) << hexdigit(C & 0x0F);

  }

}

void llvm::printHTMLEscaped(StringRef String, raw_ostream &Out) {

  for (char C : String) {

    if (C == '&')

      Out << "&amp;";

    else if (C == '<')

      Out << "&lt;";

    else if (C == '>')

      Out << "&gt;";

    else if (C == '\"')

      Out << "&quot;";

    else if (C == '\'')

      Out << "&apos;";

    else

      Out << C;

  }

}

void llvm::printLowerCase(StringRef String, raw_ostream &Out) {

  for (const char C : String)

    Out << toLower(C);

}

std::string llvm::convertToSnakeFromCamelCase(StringRef input) {

  if (input.empty())

    return "";

  std::string snakeCase;

  snakeCase.reserve(input.size());

  for (char c : input) {

    if (!std::isupper(c)) {

      snakeCase.push_back(c);

      continue;

    }

    if (!snakeCase.empty() && snakeCase.back() != '_')

      snakeCase.push_back('_');

    snakeCase.push_back(llvm::toLower(c));

  }

  return snakeCase;

}

std::string llvm::convertToCamelFromSnakeCase(StringRef input,

                                              bool capitalizeFirst) {

  if (input.empty())

    return "";

  std::string output;

  output.reserve(input.size());

  // Push the first character, capatilizing if necessary.

  if (capitalizeFirst && std::islower(input.front()))

    output.push_back(llvm::toUpper(input.front()));

  else

    output.push_back(input.front());

  // Walk the input converting any `*_[a-z]` snake case into `*[A-Z]` camelCase.

  for (size_t pos = 1, e = input.size(); pos < e; ++pos) {

    if (input[pos] == '_' && pos != (e - 1) && std::islower(input[pos + 1]))

      output.push_back(llvm::toUpper(input[++pos]));

    else

      output.push_back(input[pos]);

  }

  return output;

}