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#include "llvm/ADT/StringRef.h" 16 17namespace llvm { 18namespace sys { 19namespace unicode { 20 21enum ColumnWidthErrors { 22 ErrorInvalidUTF8 = -2, 23 ErrorNonPrintableCharacter = -1 24}; 25 26/// Determines if a character is likely to be displayed correctly on the 27/// terminal. Exact implementation would have to depend on the specific 28/// terminal, so we define the semantic that should be suitable for generic case 29/// of a terminal capable to output Unicode characters. 30/// 31/// All characters from the Unicode code point range are considered printable 32/// except for: 33/// * C0 and C1 control character ranges; 34/// * default ignorable code points as per 5.21 of 35/// http://www.unicode.org/versions/Unicode6.2.0/UnicodeStandard-6.2.pdf 36/// except for U+00AD SOFT HYPHEN, as it's actually displayed on most 37/// terminals; 38/// * format characters (category = Cf); 39/// * surrogates (category = Cs); 40/// * unassigned characters (category = Cn). 41/// \return true if the character is considered printable. 42bool isPrintable(int UCS); 43 44/// Gets the number of positions the UTF8-encoded \p Text is likely to occupy 45/// when output on a terminal ("character width"). This depends on the 46/// implementation of the terminal, and there's no standard definition of 47/// character width. 48/// 49/// The implementation defines it in a way that is expected to be compatible 50/// with a generic Unicode-capable terminal. 51/// 52/// \return Character width: 53/// * ErrorNonPrintableCharacter (-1) if \p Text contains non-printable 54/// characters (as identified by isPrintable); 55/// * 0 for each non-spacing and enclosing combining mark; 56/// * 2 for each CJK character excluding halfwidth forms; 57/// * 1 for each of the remaining characters. 58int columnWidthUTF8(StringRef Text); 59 60} // namespace unicode 61} // namespace sys 62} // namespace llvm 63