mirror of https://github.com/rusefi/lua.git
analizador lexico de LUA
This commit is contained in:
Roberto Ierusalimschy
parent
f65ebced50
commit
2058cc1dd9
|
|
@ -0,0 +1,207 @@
|
|||
char *rcs_lex = "$Id$";
|
||||
/*$Log$*/
|
||||
|
||||
#include <ctype.h>
|
||||
#include <math.h>
|
||||
|
||||
#include "opcode.h"
|
||||
#include "hash.h"
|
||||
#include "inout.h"
|
||||
#include "table.h"
|
||||
#include "y.tab.h"
|
||||
|
||||
#define next() { current = input(); }
|
||||
#define save(x) { *yytextLast++ = (x); }
|
||||
#define save_and_next() { save(current); next(); }
|
||||
|
||||
static int current;
|
||||
static char yytext[256];
|
||||
static char *yytextLast;
|
||||
|
||||
static Input input;
|
||||
|
||||
void lua_setinput (Input fn)
|
||||
{
|
||||
current = ' ';
|
||||
input = fn;
|
||||
}
|
||||
|
||||
char *lua_lasttext (void)
|
||||
{
|
||||
*yytextLast = 0;
|
||||
return yytext;
|
||||
}
|
||||
|
||||
|
||||
static struct
|
||||
{
|
||||
char *name;
|
||||
int token;
|
||||
} reserved [] = {
|
||||
{"and", AND},
|
||||
{"do", DO},
|
||||
{"else", ELSE},
|
||||
{"elseif", ELSEIF},
|
||||
{"end", END},
|
||||
{"function", FUNCTION},
|
||||
{"if", IF},
|
||||
{"local", LOCAL},
|
||||
{"nil", NIL},
|
||||
{"not", NOT},
|
||||
{"or", OR},
|
||||
{"repeat", REPEAT},
|
||||
{"return", RETURN},
|
||||
{"then", THEN},
|
||||
{"until", UNTIL},
|
||||
{"while", WHILE} };
|
||||
|
||||
#define RESERVEDSIZE (sizeof(reserved)/sizeof(reserved[0]))
|
||||
|
||||
|
||||
int findReserved (char *name)
|
||||
{
|
||||
int l = 0;
|
||||
int h = RESERVEDSIZE - 1;
|
||||
while (l <= h)
|
||||
{
|
||||
int m = (l+h)/2;
|
||||
int comp = strcmp(name, reserved[m].name);
|
||||
if (comp < 0)
|
||||
h = m-1;
|
||||
else if (comp == 0)
|
||||
return reserved[m].token;
|
||||
else
|
||||
l = m+1;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
int yylex ()
|
||||
{
|
||||
while (1)
|
||||
{
|
||||
yytextLast = yytext;
|
||||
switch (current)
|
||||
{
|
||||
case 0: return 0;
|
||||
case '\n': lua_linenumber++;
|
||||
case ' ':
|
||||
case '\t':
|
||||
save_and_next();
|
||||
continue;
|
||||
|
||||
case '-':
|
||||
save_and_next();
|
||||
if (current != '-') return '-';
|
||||
do { save_and_next(); } while (current != '\n' && current != 0);
|
||||
continue;
|
||||
|
||||
case '<':
|
||||
save_and_next();
|
||||
if (current != '=') return '<';
|
||||
else { save_and_next(); return LE; }
|
||||
|
||||
case '>':
|
||||
save_and_next();
|
||||
if (current != '=') return '>';
|
||||
else { save_and_next(); return GE; }
|
||||
|
||||
case '~':
|
||||
save_and_next();
|
||||
if (current != '=') return '~';
|
||||
else { save_and_next(); return NE; }
|
||||
|
||||
case '"':
|
||||
case '\'':
|
||||
{
|
||||
int del = current;
|
||||
next(); /* skip the delimiter */
|
||||
while (current != del)
|
||||
{
|
||||
switch (current)
|
||||
{
|
||||
case 0:
|
||||
case '\n':
|
||||
return WRONGTOKEN;
|
||||
case '\\':
|
||||
next(); /* do not save the '\' */
|
||||
switch (current)
|
||||
{
|
||||
case 'n': save('\n'); next(); break;
|
||||
case 't': save('\t'); next(); break;
|
||||
case 'r': save('\r'); next(); break;
|
||||
default : save('\\'); break;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
save_and_next();
|
||||
}
|
||||
}
|
||||
next(); /* skip the delimiter */
|
||||
*yytextLast = 0;
|
||||
yylval.vWord = lua_findconstant (yytext);
|
||||
return STRING;
|
||||
}
|
||||
|
||||
case 'a': case 'b': case 'c': case 'd': case 'e':
|
||||
case 'f': case 'g': case 'h': case 'i': case 'j':
|
||||
case 'k': case 'l': case 'm': case 'n': case 'o':
|
||||
case 'p': case 'q': case 'r': case 's': case 't':
|
||||
case 'u': case 'v': case 'w': case 'x': case 'y':
|
||||
case 'z':
|
||||
case 'A': case 'B': case 'C': case 'D': case 'E':
|
||||
case 'F': case 'G': case 'H': case 'I': case 'J':
|
||||
case 'K': case 'L': case 'M': case 'N': case 'O':
|
||||
case 'P': case 'Q': case 'R': case 'S': case 'T':
|
||||
case 'U': case 'V': case 'W': case 'X': case 'Y':
|
||||
case 'Z':
|
||||
case '_':
|
||||
{
|
||||
int res;
|
||||
do { save_and_next(); } while (isalnum(current) || current == '_');
|
||||
*yytextLast = 0;
|
||||
res = findReserved(yytext);
|
||||
if (res) return res;
|
||||
yylval.vWord = lua_findsymbol(yytext);
|
||||
return NAME;
|
||||
}
|
||||
|
||||
case '.':
|
||||
save_and_next();
|
||||
if (current == '.')
|
||||
{
|
||||
save_and_next();
|
||||
return CONC;
|
||||
}
|
||||
else if (!isdigit(current)) return '.';
|
||||
/* current is a digit: goes through to number */
|
||||
goto fraction;
|
||||
|
||||
case '0': case '1': case '2': case '3': case '4':
|
||||
case '5': case '6': case '7': case '8': case '9':
|
||||
|
||||
do { save_and_next(); } while (isdigit(current));
|
||||
if (current == '.') save_and_next();
|
||||
fraction: while (isdigit(current)) save_and_next();
|
||||
if (current == 'e' || current == 'E')
|
||||
{
|
||||
save_and_next();
|
||||
if (current == '+' || current == '-') save_and_next();
|
||||
if (!isdigit(current)) return WRONGTOKEN;
|
||||
do { save_and_next(); } while (isdigit(current));
|
||||
}
|
||||
*yytextLast = 0;
|
||||
yylval.vFloat = atof(yytext);
|
||||
return NUMBER;
|
||||
|
||||
default:
|
||||
{
|
||||
int temp = current;
|
||||
save_and_next();
|
||||
return temp;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue