solidity/libsolutil/StringUtils.h

246 lines
7.5 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity 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
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
// SPDX-License-Identifier: GPL-3.0
/** @file StringUtils.h
* @author Balajiganapathi S <balajiganapathi.s@gmail.com>
* @date 2017
*
* String routines
*/
#pragma once
#include <libsolutil/CommonData.h>
#include <libsolutil/Numeric.h>
#include <algorithm>
#include <limits>
#include <locale>
#include <string>
#include <vector>
namespace solidity::util
{
// Calculates the DamerauLevenshtein distance between _str1 and _str2 and returns true if that distance is not greater than _maxDistance
// if _lenThreshold > 0 and the product of the strings length is greater than _lenThreshold, the function will return false
bool stringWithinDistance(std::string const& _str1, std::string const& _str2, size_t _maxDistance, size_t _lenThreshold = 0);
// Calculates the DamerauLevenshtein distance between _str1 and _str2
size_t stringDistance(std::string const& _str1, std::string const& _str2);
// Return a string having elements of suggestions as quoted, alternative suggestions. e.g. "a", "b" or "c"
std::string quotedAlternativesList(std::vector<std::string> const& suggestions);
/// @returns a string containing a comma-separated list of variable names consisting of @a _baseName suffixed
/// with increasing integers in the range [@a _startSuffix, @a _endSuffix), if @a _startSuffix < @a _endSuffix,
/// and with decreasing integers in the range [@a _endSuffix, @a _startSuffix), if @a _endSuffix < @a _startSuffix.
/// If @a _startSuffix == @a _endSuffix, the empty string is returned.
std::string suffixedVariableNameList(std::string const& _baseName, size_t _startSuffix, size_t _endSuffix);
/// Joins collection of strings into one string with separators between, last separator can be different.
/// @param _list collection of strings to join
/// @param _separator defaults to ", "
/// @param _lastSeparator (optional) will be used to separate last two strings instead of _separator
/// @example join(vector<string>{"a", "b", "c"}, "; ", " or ") == "a; b or c"
template<class T>
std::string joinHumanReadable
(
T const& _list,
std::string const& _separator = ", ",
std::string const& _lastSeparator = ""
)
{
auto const itEnd = end(_list);
std::string result;
for (auto it = begin(_list); it != itEnd; )
{
std::string element = *it;
bool first = (it == begin(_list));
++it;
if (!first)
{
if (it == itEnd && !_lastSeparator.empty())
result += _lastSeparator; // last iteration
else
result += _separator;
}
result += std::move(element);
}
return result;
}
/// Joins collection of strings just like joinHumanReadable, but prepends the separator
/// unless the collection is empty.
template<class T>
std::string joinHumanReadablePrefixed
(
T const& _list,
std::string const& _separator = ", ",
std::string const& _lastSeparator = ""
)
{
if (begin(_list) == end(_list))
return {};
else
return _separator + joinHumanReadable(_list, _separator, _lastSeparator);
}
/// Formats large numbers to be easily readable by humans.
/// Returns decimal representation for smaller numbers; hex for large numbers.
/// "Special" numbers, powers-of-two and powers-of-two minus 1, are returned in
/// formulaic form like 0x01 * 2**24 - 1.
/// @a T will typically by unsigned, u160, u256 or bigint.
/// @param _value to be formatted
/// @param _useTruncation if true, internal truncation is also applied,
/// like 0x5555...{+56 more}...5555
/// @example formatNumber((u256)0x7ffffff)
template <class T>
inline std::string formatNumberReadable(
T const& _value,
bool _useTruncation = false
)
{
static_assert(
std::is_same<bigint, T>::value || !std::numeric_limits<T>::is_signed,
"only unsigned types or bigint supported"
); //bigint does not carry sign bit on shift
// smaller numbers return as decimal
if (_value <= 0x1000000)
return _value.str();
HexCase hexcase = HexCase::Mixed;
HexPrefix prefix = HexPrefix::Add;
// when multiple trailing zero bytes, format as N * 2**x
int i = 0;
T v = _value;
for (; (v & 0xff) == 0; v >>= 8)
++i;
if (i > 2)
{
// 0x100 yields 2**8 (N is 1 and redundant)
if (v == 1)
return "2**" + std::to_string(i * 8);
return toHex(toCompactBigEndian(v), prefix, hexcase) +
" * 2**" +
std::to_string(i * 8);
}
// when multiple trailing FF bytes, format as N * 2**x - 1
i = 0;
for (v = _value; (v & 0xff) == 0xff; v >>= 8)
++i;
if (i > 2)
{
// 0xFF yields 2**8 - 1 (v is 0 in that case)
if (v == 0)
return "2**" + std::to_string(i * 8) + " - 1";
return toHex(toCompactBigEndian(T(v + 1)), prefix, hexcase) +
" * 2**" + std::to_string(i * 8) +
" - 1";
}
std::string str = toHex(toCompactBigEndian(_value), prefix, hexcase);
if (_useTruncation)
{
// return as interior-truncated hex.
size_t len = str.size();
if (len < 24)
return str;
size_t const initialChars = (prefix == HexPrefix::Add) ? 6 : 4;
size_t const finalChars = 4;
size_t numSkipped = len - initialChars - finalChars;
return str.substr(0, initialChars) +
"...{+" +
std::to_string(numSkipped) +
" more}..." +
str.substr(len-finalChars, len);
}
// otherwise, show whole value.
return str;
}
/// Safely converts an usigned integer as string into an unsigned int type.
///
/// @return the converted number or nullopt in case of an failure (including if it would not fit).
inline std::optional<unsigned> toUnsignedInt(std::string const& _value)
{
try
{
auto const ulong = stoul(_value);
if (ulong > std::numeric_limits<unsigned>::max())
return std::nullopt;
return static_cast<unsigned>(ulong);
}
catch (...)
{
return std::nullopt;
}
}
/// Converts parameter _c to its lowercase equivalent if c is an uppercase letter and has a lowercase equivalent. It uses the classic "C" locale semantics.
/// @param _c value to be converted
/// @return the converted value
inline char toLower(char _c)
{
return tolower(_c, std::locale::classic());
}
/// Converts parameter _c to its uppercase equivalent if c is an lowercase letter and has a uppercase equivalent. It uses the classic "C" locale semantics.
/// @param _c value to be converted
/// @return the converted value
inline char toUpper(char _c)
{
return toupper(_c, std::locale::classic());
}
/// Converts parameter _s to its lowercase equivalent. It uses the classic "C" locale semantics.
/// @param _s value to be converted
/// @return the converted value
inline std::string toLower(std::string _s)
{
std::transform(_s.begin(), _s.end(), _s.begin(), [](char _c) {
return toLower(_c);
});
return _s;
}
/// Checks whether _c is a decimal digit character. It uses the classic "C" locale semantics.
/// @param _c character to be checked
/// @return true if _c is a decimal digit character, false otherwise
inline bool isDigit(char _c)
{
return isdigit(_c, std::locale::classic());
}
// Checks if character is printable using classic "C" locale
/// @param _c character to be checked
/// @return true if _c is a printable character, false otherwise.
inline bool isPrint(char _c)
{
return isprint(_c, std::locale::classic());
}
}