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#include <assert.h>
#include <string.h>
#include <ctype.h>
#include "compiler.h"
struct lexeme LEXEMES[MAX_LEXEMES] = {0};
size_t N_LEXEMES = 0;
void lex(char *s) {
for (char *ptr = s; *ptr; ptr++)
*ptr = tolower(*ptr);
char *LAST_LINE = s;
size_t LAST_LINE_NO = 1;
for (; *s; s++) {
enum lex_label label = LEX_NONE;
char *start = s;
// TODO: at the very least, also need to lex here: string literals,
// character literals, hex literals, int literals, identifiers.
// Note in these examples below, the first four are cases where we
// throw away some characters (indicated by label = LEX_NONE). In the
// final example we lex operation characters like [ and !=.
assert(!"unimplemented");
if (isspace(*s));
else if (prefix(s, "/*")) {
for (; *s && !prefix(s, "*/"); s++);
if (*s) s++;
} else if (prefix(s, "//")) {
for (; *s && *s != '\n'; s++);
} else if (s[0] == '#') {
for (; *s && *s != '\n'; s++)
s += (*s == '\\');
} else {
label = LEX_OP;
if (strchr("()[]{}.:?,;", *s))
s++;
else if (prefix(s, "->"))
s += 2;
else if (strchr("-+&|", *s) && *s == s[1])
s += 2;
else if (prefix(s, "<<") || prefix(s, ">>"))
s += 2 + (s[2] == '=');
else
s += 1 + (s[1] == '=');
}
// NOTE: This shared code builds the lexeme for you & inserts it into
// the array of lexemes. Basically, you need to point @s to one-past
// the last character you want to be part of the lexeme, and set @label
// to whatever label you want it to have.
if (label == LEX_NONE) continue;
assert(N_LEXEMES < sizeof(LEXEMES) / sizeof(LEXEMES[0]));
LEXEMES[N_LEXEMES].string = strndup(start, (size_t)(s - start));
LEXEMES[N_LEXEMES].label = label;
for (; LAST_LINE != start; LAST_LINE++)
LAST_LINE_NO += (*LAST_LINE == '\n');
LEXEMES[N_LEXEMES++].line_no = LAST_LINE_NO;
s--;
}
}
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