timewarrior/src/Lexer.cpp
2015-12-20 22:00:02 -05:00

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////////////////////////////////////////////////////////////////////////////////
//
// Copyright 2013 - 2015, Paul Beckingham, Federico Hernandez.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// http://www.opensource.org/licenses/mit-license.php
//
////////////////////////////////////////////////////////////////////////////////
#include <cmake.h>
#include <Lexer.h>
#include <algorithm>
#include <ctype.h>
#include <utf8.h>
////////////////////////////////////////////////////////////////////////////////
Lexer::Lexer (const std::string& text)
: _text (text)
, _cursor (0)
, _eos (text.size ())
{
}
////////////////////////////////////////////////////////////////////////////////
// When a Lexer object is constructed with a string, this method walks through
// the stream of low-level tokens.
bool Lexer::token (std::string& token, Lexer::Type& type)
{
// Eat white space.
while (isWhitespace (_text[_cursor]))
utf8_next_char (_text, _cursor);
// Terminate at EOS.
if (isEOS ())
return false;
if (isString (token, type, "'\"") ||
isHexNumber (token, type) ||
isNumber (token, type) ||
isWord (token, type))
return true;
return false;
}
////////////////////////////////////////////////////////////////////////////////
// No L10N - these are for internal purposes.
const std::string Lexer::typeName (const Lexer::Type& type)
{
switch (type)
{
case Lexer::Type::number: return "number";
case Lexer::Type::hex: return "hex";
case Lexer::Type::string: return "string";
case Lexer::Type::word: return "word";
}
return "unknown";
}
////////////////////////////////////////////////////////////////////////////////
// Complete Unicode whitespace list.
//
// http://en.wikipedia.org/wiki/Whitespace_character
// Updated 2015-09-13
// Static
//
// TODO This list should be derived from the Unicode database.
bool Lexer::isWhitespace (int c)
{
return (c == 0x0020 || // space Common Separator, space
c == 0x0009 || // Common Other, control HT, Horizontal Tab
c == 0x000A || // Common Other, control LF, Line feed
c == 0x000B || // Common Other, control VT, Vertical Tab
c == 0x000C || // Common Other, control FF, Form feed
c == 0x000D || // Common Other, control CR, Carriage return
c == 0x0085 || // Common Other, control NEL, Next line
c == 0x00A0 || // no-break space Common Separator, space
c == 0x1680 || // ogham space mark Ogham Separator, space
c == 0x180E || // mongolian vowel separator Mongolian Separator, space
c == 0x2000 || // en quad Common Separator, space
c == 0x2001 || // em quad Common Separator, space
c == 0x2002 || // en space Common Separator, space
c == 0x2003 || // em space Common Separator, space
c == 0x2004 || // three-per-em space Common Separator, space
c == 0x2005 || // four-per-em space Common Separator, space
c == 0x2006 || // six-per-em space Common Separator, space
c == 0x2007 || // figure space Common Separator, space
c == 0x2008 || // punctuation space Common Separator, space
c == 0x2009 || // thin space Common Separator, space
c == 0x200A || // hair space Common Separator, space
c == 0x200B || // zero width space
c == 0x200C || // zero width non-joiner
c == 0x200D || // zero width joiner
c == 0x2028 || // line separator Common Separator, line
c == 0x2029 || // paragraph separator Common Separator, paragraph
c == 0x202F || // narrow no-break space Common Separator, space
c == 0x205F || // medium mathematical space Common Separator, space
c == 0x2060 || // word joiner
c == 0x3000); // ideographic space Common Separator, space
}
////////////////////////////////////////////////////////////////////////////////
// Digits 0-9.
//
// TODO This list should be derived from the Unicode database.
bool Lexer::isDigit (int c)
{
return c >= 0x30 && c <= 0x39;
}
////////////////////////////////////////////////////////////////////////////////
// Digits 0-9 a-f A-F.
bool Lexer::isHexDigit (int c)
{
return (c >= '0' && c <= '9') ||
(c >= 'a' && c <= 'f') ||
(c >= 'A' && c <= 'F');
}
////////////////////////////////////////////////////////////////////////////////
// Lexer::Type::number
// \d+
// [ . \d+ ]
// [ e|E [ +|- ] \d+ [ . \d+ ] ]
// not followed by non-operator.
bool Lexer::isNumber (std::string& token, Lexer::Type& type)
{
std::size_t marker = _cursor;
if (isDigit (_text[marker]))
{
++marker;
while (isDigit (_text[marker]))
utf8_next_char (_text, marker);
if (_text[marker] == '.')
{
++marker;
if (isDigit (_text[marker]))
{
++marker;
while (isDigit (_text[marker]))
utf8_next_char (_text, marker);
}
}
if (_text[marker] == 'e' ||
_text[marker] == 'E')
{
++marker;
if (_text[marker] == '+' ||
_text[marker] == '-')
++marker;
if (isDigit (_text[marker]))
{
++marker;
while (isDigit (_text[marker]))
utf8_next_char (_text, marker);
if (_text[marker] == '.')
{
++marker;
if (isDigit (_text[marker]))
{
++marker;
while (isDigit (_text[marker]))
utf8_next_char (_text, marker);
}
}
}
}
// Lookahread: !<isWhitespace> | !<isSingleCharOperator>
// If there is an immediately consecutive character, that is not an operator, fail.
if (_eos > marker &&
! isWhitespace (_text[marker]) &&
! isSingleCharOperator (_text[marker]))
return false;
token = _text.substr (_cursor, marker - _cursor);
type = Lexer::Type::number;
_cursor = marker;
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// Lexer::Type::number
// \d+
bool Lexer::isInteger (std::string& token, Lexer::Type& type)
{
std::size_t marker = _cursor;
if (isDigit (_text[marker]))
{
++marker;
while (isDigit (_text[marker]))
utf8_next_char (_text, marker);
token = _text.substr (_cursor, marker - _cursor);
type = Lexer::Type::number;
_cursor = marker;
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
bool Lexer::isSingleCharOperator (int c)
{
return c == '+' || // Addition
c == '-' || // Subtraction or unary minus = ambiguous
c == '*' || // Multiplication
c == '/' || // Diviѕion
c == '(' || // Precedence open parenthesis
c == ')' || // Precedence close parenthesis
c == '<' || // Less than
c == '>' || // Greater than
c == '^' || // Exponent
c == '!' || // Unary not
c == '%' || // Modulus
c == '=' || // Partial match
c == '~'; // Pattern match
}
////////////////////////////////////////////////////////////////////////////////
bool Lexer::isHardBoundary (int left, int right)
{
// EOS
if (right == '\0')
return true;
// FILTER operators that don't need to be surrounded by whitespace.
if (left == '(' ||
left == ')' ||
right == '(' ||
right == ')')
return true;
return false;
}
////////////////////////////////////////////////////////////////////////////////
bool Lexer::isEOS () const
{
return _cursor >= _eos;
}
////////////////////////////////////////////////////////////////////////////////
// Converts '0' -> 0
// '9' -> 9
// 'a'/'A' -> 10
// 'f'/'F' -> 15
int Lexer::hexToInt (int c)
{
if (c >= '0' && c <= '9') return (c - '0');
else if (c >= 'a' && c <= 'f') return (c - 'a' + 10);
else return (c - 'A' + 10);
}
////////////////////////////////////////////////////////////////////////////////
int Lexer::hexToInt (int c0, int c1)
{
return (hexToInt (c0) << 4) + hexToInt (c1);
}
////////////////////////////////////////////////////////////////////////////////
int Lexer::hexToInt (int c0, int c1, int c2, int c3)
{
return (hexToInt (c0) << 12) +
(hexToInt (c1) << 8) +
(hexToInt (c2) << 4) +
hexToInt (c3);
}
////////////////////////////////////////////////////////////////////////////////
std::string Lexer::trimLeft (const std::string& in, const std::string& t /*= " "*/)
{
std::string::size_type ws = in.find_first_not_of (t);
if (ws > 0)
{
std::string out {in};
return out.erase (0, ws);
}
return in;
}
////////////////////////////////////////////////////////////////////////////////
std::string Lexer::trimRight (const std::string& in, const std::string& t /*= " "*/)
{
std::string out {in};
return out.erase (in.find_last_not_of (t) + 1);
}
////////////////////////////////////////////////////////////////////////////////
std::string Lexer::trim (const std::string& in, const std::string& t /*= " "*/)
{
return trimLeft (trimRight (in, t), t);
}
////////////////////////////////////////////////////////////////////////////////
// Lexer::Type::string
// '|"
// [ U+XXXX | \uXXXX | \" | \' | \\ | \/ | \b | \f | \n | \r | \t | . ]
// '|"
bool Lexer::isString (std::string& token, Lexer::Type& type, const std::string& quotes)
{
std::size_t marker = _cursor;
if (readWord (_text, quotes, marker, token))
{
type = Lexer::Type::string;
_cursor = marker;
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// Lexer::Type::hex
// 0xX+
bool Lexer::isHexNumber (std::string& token, Lexer::Type& type)
{
std::size_t marker = _cursor;
if (_eos - marker >= 3 &&
_text[marker + 0] == '0' &&
_text[marker + 1] == 'x')
{
marker += 2;
while (isHexDigit (_text[marker]))
++marker;
if (marker - _cursor > 2)
{
token = _text.substr (_cursor, marker - _cursor);
type = Lexer::Type::hex;
_cursor = marker;
return true;
}
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// Lexer::Type::word
// [^\s]+
bool Lexer::isWord (std::string& token, Lexer::Type& type)
{
std::size_t marker = _cursor;
while (_text[marker] &&
! isWhitespace (_text[marker]) &&
! isSingleCharOperator (_text[marker]))
utf8_next_char (_text, marker);
if (marker > _cursor)
{
token = _text.substr (_cursor, marker - _cursor);
type = Lexer::Type::word;
_cursor = marker;
return true;
}
return false;
}
////////////////////////////////////////////////////////////////////////////////
// Static
std::string Lexer::typeToString (Lexer::Type type)
{
if (type == Lexer::Type::string) return std::string ("\033[38;5;7m\033[48;5;3m") + "string" + "\033[0m";
else if (type == Lexer::Type::hex) return std::string ("\033[38;5;7m\033[48;5;14m") + "hex" + "\033[0m";
else if (type == Lexer::Type::number) return std::string ("\033[38;5;7m\033[48;5;6m") + "number" + "\033[0m";
else if (type == Lexer::Type::word) return std::string ("\033[38;5;15m\033[48;5;236m") + "word" + "\033[0m";
else return std::string ("\033[37;41m") + "unknown" + "\033[0m";
}
////////////////////////////////////////////////////////////////////////////////
// Full implementation of a quoted word. Includes:
// '\''
// '"'
// "'"
// "\""
// 'one two'
// Result includes the quotes.
bool Lexer::readWord (
const std::string& text,
const std::string& quotes,
std::string::size_type& cursor,
std::string& word)
{
if (quotes.find (text[cursor]) == std::string::npos)
return false;
std::string::size_type eos = text.length ();
int quote = text[cursor++];
word = quote;
int c;
while ((c = text[cursor]))
{
// Quoted word ends on a quote.
if (quote && quote == c)
{
word += utf8_character (utf8_next_char (text, cursor));
break;
}
// Unicode U+XXXX or \uXXXX codepoint.
else if (eos - cursor >= 6 &&
((text[cursor + 0] == 'U' && text[cursor + 1] == '+') ||
(text[cursor + 0] == '\\' && text[cursor + 1] == 'u')) &&
isHexDigit (text[cursor + 2]) &&
isHexDigit (text[cursor + 3]) &&
isHexDigit (text[cursor + 4]) &&
isHexDigit (text[cursor + 5]))
{
word += utf8_character (
hexToInt (
text[cursor + 2],
text[cursor + 3],
text[cursor + 4],
text[cursor + 5]));
cursor += 6;
}
// An escaped thing.
else if (c == '\\')
{
c = text[++cursor];
switch (c)
{
case '"': word += (char) 0x22; ++cursor; break;
case '\'': word += (char) 0x27; ++cursor; break;
case '\\': word += (char) 0x5C; ++cursor; break;
case 'b': word += (char) 0x08; ++cursor; break;
case 'f': word += (char) 0x0C; ++cursor; break;
case 'n': word += (char) 0x0A; ++cursor; break;
case 'r': word += (char) 0x0D; ++cursor; break;
case 't': word += (char) 0x09; ++cursor; break;
case 'v': word += (char) 0x0B; ++cursor; break;
// This pass-through default case means that anything can be escaped
// harmlessly. In particular 'quote' is included, if it not one of the
// above characters.
default: word += (char) c; ++cursor; break;
}
}
// Ordinary character.
else
word += utf8_character (utf8_next_char (text, cursor));
}
// Verify termination.
return word[0] == quote &&
word[word.length () - 1] == quote &&
word.length () >= 2;
}
////////////////////////////////////////////////////////////////////////////////
// Full implementation of an unquoted word. Includes:
// one\ two
// abcU+0020def
// abc\u0020def
// a\tb
//
// Ends at:
// Lexer::isEOS
// Lexer::isWhitespace
// Lexer::isHardBoundary
bool Lexer::readWord (
const std::string& text,
std::string::size_type& cursor,
std::string& word)
{
std::string::size_type eos = text.length ();
word = "";
int c;
int prev = 0;
while ((c = text[cursor])) // Handles EOS.
{
// Unquoted word ends on white space.
if (Lexer::isWhitespace (c))
break;
// Parentheses mostly.
if (prev && Lexer::isHardBoundary (prev, c))
break;
// Unicode U+XXXX or \uXXXX codepoint.
else if (eos - cursor >= 6 &&
((text[cursor + 0] == 'U' && text[cursor + 1] == '+') ||
(text[cursor + 0] == '\\' && text[cursor + 1] == 'u')) &&
isHexDigit (text[cursor + 2]) &&
isHexDigit (text[cursor + 3]) &&
isHexDigit (text[cursor + 4]) &&
isHexDigit (text[cursor + 5]))
{
word += utf8_character (
hexToInt (
text[cursor + 2],
text[cursor + 3],
text[cursor + 4],
text[cursor + 5]));
cursor += 6;
}
// An escaped thing.
else if (c == '\\')
{
c = text[++cursor];
switch (c)
{
case '"': word += (char) 0x22; ++cursor; break;
case '\'': word += (char) 0x27; ++cursor; break;
case '\\': word += (char) 0x5C; ++cursor; break;
case 'b': word += (char) 0x08; ++cursor; break;
case 'f': word += (char) 0x0C; ++cursor; break;
case 'n': word += (char) 0x0A; ++cursor; break;
case 'r': word += (char) 0x0D; ++cursor; break;
case 't': word += (char) 0x09; ++cursor; break;
case 'v': word += (char) 0x0B; ++cursor; break;
// This pass-through default case means that anything can be escaped
// harmlessly. In particular 'quote' is included, if it not one of the
// above characters.
default: word += (char) c; ++cursor; break;
}
}
// Ordinary character.
else
word += utf8_character (utf8_next_char (text, cursor));
prev = c;
}
return word.length () > 0 ? true : false;
}
////////////////////////////////////////////////////////////////////////////////