1//===--- NumericLiteralInfo.cpp ---------------------------------*- 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-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10/// This file implements the functionality of getting information about a
11/// numeric literal string, including 0-based positions of the base letter, the
12/// decimal/hexadecimal point, the exponent letter, and the suffix, or npos if
13/// absent.
14///
15//===----------------------------------------------------------------------===//
16
17#include "NumericLiteralInfo.h"
18#include "llvm/ADT/StringExtras.h"
19#include <algorithm>
20
21namespace clang {
22namespace format {
23
24using namespace llvm;
25
26NumericLiteralInfo::NumericLiteralInfo(StringRef Text, char Separator) {
27 if (Text.size() < 2)
28 return;
29
30 bool IsHex = false;
31 if (Text[0] == '0') {
32 switch (Text[1]) {
33 case 'x':
34 case 'X':
35 IsHex = true;
36 [[fallthrough]];
37 case 'b':
38 case 'B':
39 case 'o': // JavaScript octal.
40 case 'O':
41 BaseLetterPos = 1; // e.g. 0xF
42 break;
43 }
44 }
45
46 DotPos = Text.find(C: '.', From: BaseLetterPos + 1); // e.g. 0x.1 or .1
47
48 // e.g. 1.e2 or 0xFp2
49 const auto Pos = DotPos != StringRef::npos ? DotPos + 1 : BaseLetterPos + 2;
50 // Trim C++ user-defined suffix as in `1_Pa`.
51 const auto TrimmedText =
52 Separator == '\'' ? Text.take_front(N: Text.find(C: '_')) : Text;
53
54 // Clamp searches due to possible incomplete literals.
55 ExponentLetterPos = TrimmedText.find_insensitive(
56 C: IsHex ? 'p' : 'e', From: std::min(a: Pos, b: TrimmedText.size()));
57
58 const bool HasExponent = ExponentLetterPos != StringRef::npos;
59 SuffixPos = Text.find_if_not(
60 F: [&](char C) {
61 return (HasExponent || !IsHex ? isDigit : isHexDigit)(C) ||
62 C == Separator;
63 },
64 From: std::min(a: HasExponent ? ExponentLetterPos + 2 : Pos,
65 b: Text.size())); // e.g. 1e-2f
66}
67
68} // namespace format
69} // namespace clang
70