1 //===- llvm/Support/Unicode.h - Unicode character properties -*- C++ -*-=====//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines functions that allow querying certain properties of Unicode
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_SUPPORT_UNICODE_H
16 #define LLVM_SUPPORT_UNICODE_H
18 #include "llvm/ADT/StringRef.h"
24 enum ColumnWidthErrors {
25 ErrorInvalidUTF8 = -2,
26 ErrorNonPrintableCharacter = -1
29 /// Determines if a character is likely to be displayed correctly on the
30 /// terminal. Exact implementation would have to depend on the specific
31 /// terminal, so we define the semantic that should be suitable for generic case
32 /// of a terminal capable to output Unicode characters.
34 /// All characters from the Unicode code point range are considered printable
36 /// * C0 and C1 control character ranges;
37 /// * default ignorable code points as per 5.21 of
38 /// http://www.unicode.org/versions/Unicode6.2.0/UnicodeStandard-6.2.pdf
39 /// except for U+00AD SOFT HYPHEN, as it's actually displayed on most
41 /// * format characters (category = Cf);
42 /// * surrogates (category = Cs);
43 /// * unassigned characters (category = Cn).
44 /// \return true if the character is considered printable.
45 bool isPrintable(int UCS);
47 /// Gets the number of positions the UTF8-encoded \p Text is likely to occupy
48 /// when output on a terminal ("character width"). This depends on the
49 /// implementation of the terminal, and there's no standard definition of
52 /// The implementation defines it in a way that is expected to be compatible
53 /// with a generic Unicode-capable terminal.
55 /// \return Character width:
56 /// * ErrorNonPrintableCharacter (-1) if \p Text contains non-printable
57 /// characters (as identified by isPrintable);
58 /// * 0 for each non-spacing and enclosing combining mark;
59 /// * 2 for each CJK character excluding halfwidth forms;
60 /// * 1 for each of the remaining characters.
61 int columnWidthUTF8(StringRef Text);
63 } // namespace unicode