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1//===-- lib/Evaluate/character.h --------------------------------*- 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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef FORTRAN_EVALUATE_CHARACTER_H_10#define FORTRAN_EVALUATE_CHARACTER_H_11 12#include "flang/Evaluate/type.h"13#include <string>14 15// Provides implementations of intrinsic functions operating on character16// scalars.17 18namespace Fortran::evaluate {19 20template <int KIND> class CharacterUtils {21 using Character = Scalar<Type<TypeCategory::Character, KIND>>;22 using CharT = typename Character::value_type;23 24public:25 // CHAR also implements ACHAR under assumption that character encodings26 // contain ASCII27 static Character CHAR(std::uint64_t code) {28 return Character{{static_cast<CharT>(code)}};29 }30 31 // ICHAR also implements IACHAR under assumption that character encodings32 // contain ASCII33 static std::int64_t ICHAR(const Character &c) {34 CHECK(c.length() == 1);35 // Convert first to an unsigned integer type to avoid sign extension36 return static_cast<common::HostUnsignedIntType<(8 * KIND)>>(c[0]);37 }38 39 static Character NEW_LINE() { return Character{{NewLine()}}; }40 41 static Character ADJUSTL(const Character &str) {42 auto pos{str.find_first_not_of(Space())};43 if (pos != Character::npos && pos != 0) {44 return Character{str.substr(pos) + Character(pos, Space())};45 }46 // else empty or only spaces, or no leading spaces47 return str;48 }49 50 static Character ADJUSTR(const Character &str) {51 auto pos{str.find_last_not_of(Space())};52 if (pos != Character::npos && pos != str.length() - 1) {53 auto delta{str.length() - 1 - pos};54 return Character{Character(delta, Space()) + str.substr(0, pos + 1)};55 }56 // else empty or only spaces, or no trailing spaces57 return str;58 }59 60 static ConstantSubscript INDEX(61 const Character &str, const Character &substr, bool back = false) {62 auto pos{back ? str.rfind(substr) : str.find(substr)};63 return static_cast<ConstantSubscript>(pos == str.npos ? 0 : pos + 1);64 }65 66 static ConstantSubscript SCAN(67 const Character &str, const Character &set, bool back = false) {68 auto pos{back ? str.find_last_of(set) : str.find_first_of(set)};69 return static_cast<ConstantSubscript>(pos == str.npos ? 0 : pos + 1);70 }71 72 static ConstantSubscript VERIFY(73 const Character &str, const Character &set, bool back = false) {74 auto pos{back ? str.find_last_not_of(set) : str.find_first_not_of(set)};75 return static_cast<ConstantSubscript>(pos == str.npos ? 0 : pos + 1);76 }77 78 // Resize adds spaces on the right if the new size is bigger than the79 // original, or by trimming the rightmost characters otherwise.80 static Character Resize(const Character &str, std::size_t newLength) {81 auto oldLength{str.length()};82 if (newLength > oldLength) {83 return str + Character(newLength - oldLength, Space());84 } else {85 return str.substr(0, newLength);86 }87 }88 89 static ConstantSubscript LEN_TRIM(const Character &str) {90 auto j{str.length()};91 for (; j >= 1; --j) {92 if (str[j - 1] != ' ') {93 break;94 }95 }96 return static_cast<ConstantSubscript>(j);97 }98 99 static Character REPEAT(const Character &str, ConstantSubscript ncopies) {100 Character result;101 if (!str.empty() && ncopies > 0) {102 result.reserve(ncopies * str.size());103 while (ncopies-- > 0) {104 result += str;105 }106 }107 return result;108 }109 110 static Character TRIM(const Character &str) {111 return str.substr(0, LEN_TRIM(str));112 }113 114private:115 // Following helpers assume that character encodings contain ASCII116 static constexpr CharT Space() { return 0x20; }117 static constexpr CharT NewLine() { return 0x0a; }118};119 120} // namespace Fortran::evaluate121 122#endif // FORTRAN_EVALUATE_CHARACTER_H_123