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#ifndef INCLUDE_lexerlexer
#define INCLUDE_lexerlexer
#include "token.h"
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct {
const char *buf;
int pos;
int line;
int col;
} _LX;
/* Error reporting with line/column info */
static void perror_at(_LX *lx, const char *msg) {
fprintf(stderr, "[LEXER] Error at line %d, column %d: %s\n", lx->line, lx->col, msg);
exit(1);
}
#define sic static inline char
#define sii static inline int
#define siv static inline void
#define sit static inline _T
sic lxpeek(_LX *lx) { return lx->buf[lx->pos]; }
sic lxget(_LX *lx) { return lx->buf[lx->pos++]; }
static inline char *lx_strdup_checked(_LX *lx, const char *s) {
char *p = strdup(s);
if (!p) {
perror_at(lx, "out of memory");
}
return p;
}
siv lxskipws(_LX *lx) {
while (lxpeek(lx) == ' ' || lxpeek(lx) == '\t') {
if (lxpeek(lx) == '\t') lx->col += 8; else lx->col++;
lxget(lx);
}
}
sit lxnext(_LX *lx) {
lxskipws(lx);
char c = lxpeek(lx);
if (c == 0)
return (_T){TK_EOF, 0, NULL};
// Track newlines
if (c == '\n') {
lx->line++;
lx->col = 0;
lxget(lx);
return lxnext(lx); // recurse to get next token
}
if (isalpha(c) || c == '_') {
int start = lx->pos;
while (isalnum(lxpeek(lx)) || lxpeek(lx) == '_')
lxget(lx);
int len = lx->pos - start;
char *text = strndup(lx->buf + start, len);
if (!text) {
perror_at(lx, "out of memory");
}
return (_T){checkkw(text), 0, text};
}
if (isdigit(c)) {
int start = lx->pos;
while (isdigit(lxpeek(lx)))
lxget(lx);
int len = lx->pos - start;
char *text = strndup(lx->buf + start, len);
if (!text) {
perror_at(lx, "out of memory");
}
return (_T){TK_NUMBER, atoi(text), text};
}
lxget(lx);
lx->col++;
// handle multi-char tokens
if (c == '=') {
if (lxpeek(lx) == '=') { lxget(lx); lx->col++; return (_T){TK_EQ,0,lx_strdup_checked(lx,"==")}; }
return (_T){TK_ASSIGN, 0, lx_strdup_checked(lx,"=")};
}
if (c == '!') {
if (lxpeek(lx) == '=') { lxget(lx); lx->col++; return (_T){TK_NE,0,lx_strdup_checked(lx,"!=")}; }
return (_T){TK_BANG,0,lx_strdup_checked(lx,"!")};
}
if (c == '<') {
if (lxpeek(lx) == '=') { lxget(lx); lx->col++; return (_T){TK_LE,0,lx_strdup_checked(lx,"<=")}; }
if (lxpeek(lx) == '<') { lxget(lx); lx->col++; return (_T){TK_SHL,0,lx_strdup_checked(lx,"<<")}; }
return (_T){TK_LT,0,lx_strdup_checked(lx,"<")};
}
if (c == '>') {
if (lxpeek(lx) == '=') { lxget(lx); lx->col++; return (_T){TK_GE,0,lx_strdup_checked(lx,">=")}; }
if (lxpeek(lx) == '>') { lxget(lx); lx->col++; return (_T){TK_SHR,0,lx_strdup_checked(lx,">>")}; }
return (_T){TK_GT,0,lx_strdup_checked(lx,">")};
}
if (c == '&') {
if (lxpeek(lx) == '&') { lxget(lx); lx->col++; return (_T){TK_AND,0,lx_strdup_checked(lx,"&&")}; }
}
if (c == '|') {
if (lxpeek(lx) == '|') { lxget(lx); lx->col++; return (_T){TK_OR,0,lx_strdup_checked(lx,"||")}; }
}
if (c == '"') {
// String literal
int start = lx->pos; // pos is already after the opening quote
while (lxpeek(lx) != '"' && lxpeek(lx) != 0) {
if (lxpeek(lx) == '\\') {
lxget(lx); // consume backslash
if (lxpeek(lx) != 0) lxget(lx); // consume escaped char
} else {
lxget(lx);
}
}
if (lxpeek(lx) == '"') {
int len = lx->pos - start; // length of content
lxget(lx); // consume closing quote
char *text = strndup(lx->buf + start, len); // start at content
if (!text) {
perror_at(lx, "out of memory");
}
return (_T){TK_STRING, 0, text};
} else {
perror_at(lx, "unterminated string literal");
}
}
switch (c) {
case '(':
return (_T){TK_LPAREN, 0, lx_strdup_checked(lx,"(")};
case ')':
return (_T){TK_RPAREN, 0, lx_strdup_checked(lx,")")};
case '{':
return (_T){TK_LBRACE, 0, lx_strdup_checked(lx,"{")};
case '}':
return (_T){TK_RBRACE, 0, lx_strdup_checked(lx,"}")};
case ';':
return (_T){TK_SEMI, 0, lx_strdup_checked(lx,";")};
case '+':
return (_T){TK_PLUS, 0, lx_strdup_checked(lx,"+")};
case '-':
return (_T){TK_MINUS, 0, lx_strdup_checked(lx,"-")};
case '*':
return (_T){TK_STAR, 0, lx_strdup_checked(lx,"*")};
case '/':
return (_T){TK_SLASH, 0, lx_strdup_checked(lx,"/")};
case '&':
return (_T){TK_AMP, 0, lx_strdup_checked(lx,"&")};
case '|':
return (_T){TK_BAR, 0, lx_strdup_checked(lx,"|")};
case '^':
return (_T){TK_CARET, 0, lx_strdup_checked(lx,"^")};
case '%':
return (_T){TK_PERCENT, 0, lx_strdup_checked(lx,"%")};
case ',':
return (_T){TK_COMMA, 0, lx_strdup_checked(lx,",")};
case '\'':
return (_T){TK_SQUOTE, 0, lx_strdup_checked(lx,"'")};
case '"':
return (_T){TK_DQUOTE, 0, lx_strdup_checked(lx,"\"")};
case '[':
return (_T){TK_LBRACKET, 0, lx_strdup_checked(lx,"[")};
case ']':
return (_T){TK_RBRACKET, 0, lx_strdup_checked(lx,"]")};
default:
return (_T){TK_INVALID, 0, NULL};
}
}
#undef sic
#undef sii
#undef siv
#undef sit
#endif
|
