1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
/**
* Utility functions for parsing numbers from strings.
*/
#pragma once
#include "mongo/base/status.h"
#include "mongo/base/string_data.h"
#include "mongo/platform/decimal128.h"
namespace mongo {
/**
* Builder pattern for setting up a number parser. Intended usage:
* long result;
* char* end;
* NumberParser()
* .base(16)
* .allowTrailingText()
* .skipWhitespace()
* ("\t\n 0x16hello, world", &result, &end);
* //end points to 'h' and result holds 22
*/
struct NumberParser {
public:
/**
* Behave like strtol/atoi and skip whitespace at the beginning of the string
*/
NumberParser& skipWhitespace(bool skipws = true) {
_skipLeadingWhitespace = skipws;
return *this;
}
/**
* Set a base for the conversion. 0 means infer the base akin to strtol.
* Legal bases are [2-35]. If a base outside of this is selected, then operator()
* will return BadValue.
*/
NumberParser& base(int b = 0) {
_base = b;
return *this;
}
/*
* Acts like atoi/strtol and will still parse even if there are non-numeric characters in the
* string after the number. Without this option, the parser will return FailedToParse if there
* are leftover characters in the parsed string.
*/
NumberParser& allowTrailingText(bool allowTrailingText = true) {
_allowTrailingText = allowTrailingText;
return *this;
}
NumberParser& setDecimal128RoundingMode(
Decimal128::RoundingMode mode = Decimal128::RoundingMode::kRoundTiesToEven) {
_roundingMode = mode;
return *this;
}
/*
* returns a NumberParser configured like strtol/atoi
*/
static NumberParser strToAny(int base = 0) {
return NumberParser().skipWhitespace().base(base).allowTrailingText();
}
/*
* Parsing overloads for different supported numerical types.
*
* On success, the parsed value is stored into *result and returns Status::OK().
* If endPtr is not nullptr, the end of the number portion of the string will be stored at
* *endPtr (like strtol).
* This will return with Status::FailedToParse if the string does not represent a number value.
* See skipWhitespace and allowTrailingText for ways to expand the parser's capabilities.
* Returns with Status::Overflow if the parsed number cannot be represented by the desired type.
* If the status is not OK, then there are no guarantees about what value will be stored in
* result.
*/
Status operator()(StringData strData, long* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, long long* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, unsigned long* result, char** endPtr = nullptr) const;
Status operator()(StringData strData,
unsigned long long* result,
char** endPtr = nullptr) const;
Status operator()(StringData strData, short* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, unsigned short* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, int* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, unsigned int* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, int8_t* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, uint8_t* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, double* result, char** endPtr = nullptr) const;
Status operator()(StringData strData, Decimal128* result, char** endPtr = nullptr) const;
int _base = 0;
Decimal128::RoundingMode _roundingMode = Decimal128::RoundingMode::kRoundTowardZero;
bool _skipLeadingWhitespace = false;
bool _allowTrailingText = false;
};
} // namespace mongo
|
