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Diffstat (limited to 'src/libs/lex/lex.cpp')
| -rw-r--r-- | src/libs/lex/lex.cpp | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/libs/lex/lex.cpp b/src/libs/lex/lex.cpp new file mode 100644 index 0000000..84891f1 --- /dev/null +++ b/src/libs/lex/lex.cpp @@ -0,0 +1,167 @@ +// BEGIN_COPYRIGHT +// +// Copyright (C) 1999 Allen Akin All Rights Reserved. +// +// 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 ALLEN AKIN 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. +// +// END_COPYRIGHT + + + + +// lex.cpp: Implementation of simple lexical analyzer + +#include <ctype.h> +#include <stdlib.h> +#include "lex.h" + +namespace GLEAN { + + +/////////////////////////////////////////////////////////////////////////////// +// Constructor: +/////////////////////////////////////////////////////////////////////////////// +Lex::Lex(const char* s, bool ignoreCase/* = false */) { + input = s; + p = input; + ignoringCase = ignoreCase; +} // Lex::Lex + +/////////////////////////////////////////////////////////////////////////////// +// next - Fetch next token from the input string +/////////////////////////////////////////////////////////////////////////////// +void +Lex::next() { + while (isspace(*p)) + ++p; + + if (isalpha(*p) || *p == '_') { + id = ""; + if (ignoringCase) + while (isalnum(*p) || *p == '_') + id += tolower(*p++); + else + while (isalnum(*p) || *p == '_') + id += *p++; + token = ID; + return; + } + + if (isdigit(*p)) { + iValue = strtol(p, const_cast<char**>(&p), 0); + token = ICONST; + return; + } + + char nextC = 0; + char c = *p++; + if (c) + nextC = *p; + switch (c) { + case '|': + if (nextC == '|') { + ++p; + token = OR_OR; + } + else + token = OR; + break; + case '&': + if (nextC == '&') { + ++p; + token = AND_AND; + } + else + token = AND; + break; + case '<': + if (nextC == '=') { + ++p; + token = LE; + } + else + token = LT; + break; + case '>': + if (nextC == '=') { + ++p; + token = GE; + } + else + token = GT; + break; + case '=': + if (nextC == '=') { + ++p; + token = EQ; + } + else + token = ASSIGN; + break; + case '!': + if (nextC == '=') { + ++p; + token = NE; + } + else + token = BANG; + break; + case '+': + token = PLUS; + break; + case '-': + token = MINUS; + break; + case '*': + token = STAR; + break; + case '/': + token = SLASH; + break; + case '%': + token = PERCENT; + break; + case ',': + token = COMMA; + break; + case '(': + token = LPAREN; + break; + case ')': + token = RPAREN; + break; + case '.': + token = DOT; + break; + case '\0': + token = END; + --p; // push back '\0' so that token will always be END + break; + default: + throw Lexical("unrecognized symbol", p - input); + } + + return; +} // Lex::next + +} // namespace GLEAN |