| 1 | //===- llvm/Support/Unicode.h - Unicode character properties -*- C++ -*-=====// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // |
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| 9 | // This file defines functions that allow querying certain properties of Unicode |
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| 10 | // characters. |
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| 11 | // |
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| 12 | //===----------------------------------------------------------------------===// |
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| 13 | |
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| 14 | #ifndef LLVM_SUPPORT_UNICODE_H |
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| 15 | #define LLVM_SUPPORT_UNICODE_H |
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| 16 | |
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| 17 | #include "llvm/ADT/SmallString.h" |
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| 18 | #include <optional> |
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| 19 | #include <string> |
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| 20 | |
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| 21 | namespace llvm { |
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| 22 | class StringRef; |
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| 23 | |
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| 24 | namespace sys { |
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| 25 | namespace unicode { |
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| 26 | |
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| 27 | enum ColumnWidthErrors { |
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| 28 | ErrorInvalidUTF8 = -2, |
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| 29 | ErrorNonPrintableCharacter = -1 |
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| 30 | }; |
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| 31 | |
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| 32 | /// Determines if a character is likely to be displayed correctly on the |
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| 33 | /// terminal. Exact implementation would have to depend on the specific |
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| 34 | /// terminal, so we define the semantic that should be suitable for generic case |
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| 35 | /// of a terminal capable to output Unicode characters. |
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| 36 | /// |
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| 37 | /// Printable codepoints are those in the categories L, M, N, P, S and Zs |
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| 38 | /// \return true if the character is considered printable. |
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| 39 | bool isPrintable(int UCS); |
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| 40 | |
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| 41 | // Formatting codepoints are codepoints in the Cf category. |
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| 42 | bool isFormatting(int UCS); |
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| 43 | |
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| 44 | /// Gets the number of positions the UTF8-encoded \p Text is likely to occupy |
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| 45 | /// when output on a terminal ("character width"). This depends on the |
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| 46 | /// implementation of the terminal, and there's no standard definition of |
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| 47 | /// character width. |
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| 48 | /// |
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| 49 | /// The implementation defines it in a way that is expected to be compatible |
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| 50 | /// with a generic Unicode-capable terminal. |
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| 51 | /// |
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| 52 | /// \return Character width: |
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| 53 | /// * ErrorNonPrintableCharacter (-1) if \p Text contains non-printable |
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| 54 | /// characters (as identified by isPrintable); |
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| 55 | /// * 0 for each non-spacing and enclosing combining mark; |
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| 56 | /// * 2 for each CJK character excluding halfwidth forms; |
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| 57 | /// * 1 for each of the remaining characters. |
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| 58 | int columnWidthUTF8(StringRef Text); |
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| 59 | |
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| 60 | /// Fold input unicode character according the Simple unicode case folding |
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| 61 | /// rules. |
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| 62 | int foldCharSimple(int C); |
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| 63 | |
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| 64 | /// Maps the name or the alias of a Unicode character to its associated |
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| 65 | /// codepoints. |
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| 66 | /// The names and aliases are derived from UnicodeData.txt and NameAliases.txt |
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| 67 | /// For compatibility with the semantics of named character escape sequences in |
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| 68 | /// C++, this mapping does an exact match sensitive to casing and spacing. |
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| 69 | /// \return The codepoint of the corresponding character, if any. |
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| 70 | std::optional<char32_t> nameToCodepointStrict(StringRef Name); |
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| 71 | |
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| 72 | struct LooseMatchingResult { |
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| 73 | char32_t CodePoint; |
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| 74 | SmallString<64> Name; |
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| 75 | }; |
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| 76 | |
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| 77 | std::optional<LooseMatchingResult> nameToCodepointLooseMatching(StringRef Name); |
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| 78 | |
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| 79 | struct MatchForCodepointName { |
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| 80 | std::string Name; |
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| 81 | uint32_t Distance = 0; |
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| 82 | char32_t Value = 0; |
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| 83 | }; |
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| 84 | |
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| 85 | SmallVector<MatchForCodepointName> |
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| 86 | nearestMatchesForCodepointName(StringRef Pattern, std::size_t MaxMatchesCount); |
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| 87 | |
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| 88 | } // namespace unicode |
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| 89 | } // namespace sys |
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| 90 | } // namespace llvm |
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| 91 | |
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| 92 | #endif |
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| 93 | |
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