1//===- llvm/Support/Unicode.h - Unicode character properties -*- C++ -*-=====// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines functions that allow querying certain properties of Unicode 11// characters. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_SUPPORT_UNICODE_H 16#define LLVM_SUPPORT_UNICODE_H 17 18#include "llvm/ADT/StringRef.h" 19 20namespace llvm { 21namespace sys { 22namespace unicode { 23 24enum ColumnWidthErrors { 25 ErrorInvalidUTF8 = -2, 26 ErrorNonPrintableCharacter = -1 27}; 28 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. 33/// 34/// All characters from the Unicode code point range are considered printable 35/// except for: 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 40/// terminals; 41/// * format characters (category = Cf); 42/// * surrogates (category = Cs); 43/// * unassigned characters (category = Cn). 44/// \return true if the character is considered printable. 45bool isPrintable(int UCS); 46 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 50/// character width. 51/// 52/// The implementation defines it in a way that is expected to be compatible 53/// with a generic Unicode-capable terminal. 54/// 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. 61int columnWidthUTF8(StringRef Text); 62 63} // namespace unicode 64} // namespace sys 65} // namespace llvm 66 67#endif 68