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#include <da.h>
#include <mbstring.h>
#include <rtype.h>
#include "cerr.h"
#include "common.h"
#include "lexer.h"
#include "macros.h"
#define ISDIGIT(n) ((n) >= '0' && (n) <= '9')
#define U8MOV(sv, n) ((sv)->p += (n), (sv)->len -= (n))
#define E_BASE "integer with invalid base specifier"
#define E_EXTRA "unknown extraneous character"
#define E_IDENTCCHAR "illegal character in identifier"
#define E_IDENTLOST "local label missing identifier"
#define E_IDENTSCHAR "illegal first character in identifier"
#define E_UNTERMINATED "unterminated string literal"
#define E_UTF8 "invalid UTF-8 byte near ‘%02X’"
#define EOLS U"\n\v\f\r\x85\u2028\u2029"
#define NUMCHARS U"'0123456789abcdefABCDEF"
static void lexline(struct tokens *, struct u8view *);
static bool skipws(struct u8view *);
const char *
tokrepr(tokkind k)
{
return (const char *[]){
[T_COLON] = "colon", [T_EOL] = "end of line",
[T_IDENT] = "identifier", [T_NUMBER] = "number",
[T_STRING] = "string",
}[k];
}
struct tokens
lexfile(void)
{
const char8_t *s;
struct tokens toks;
struct u8view sv = filebuf;
if (s = u8chk(sv.p, sv.len))
die_with_off(filename, s - sv.p, E_UTF8, *s);
dainit(&toks, 256);
while (sv.len) {
size_t len = u8cbspn(sv.p, sv.len, EOLS, lengthof(EOLS) - 1);
struct u8view line = {
.p = sv.p,
.len = len,
};
lexline(&toks, &line);
/* Skip trailing EOL */
if (sv.len > len)
len += u8rlen(sv.p + len);
U8MOV(&sv, len);
}
return toks;
}
#define DIE_AT_POS_WITH_CODE2(HL, ...) \
DIE_AT_POS_WITH_CODE((HL), sv->p - w, __VA_ARGS__)
void
lexline(struct tokens *toks, struct u8view *sv)
{
struct token tok;
for (;;) {
int w;
rune ch;
if (!skipws(sv))
goto end;
tok.sv.p = sv->p;
tok.sv.len = w = u8next(&ch, &sv->p, &sv->len);
if (ISDIGIT(ch)) {
size_t off, m = 10;
tok.kind = T_NUMBER;
tok.base = 10;
if (ch == '0') {
w = u8next(&ch, &sv->p, &sv->len);
if (!w || rprop_is_pat_ws(ch)) {
U8MOV(sv, -w);
goto out;
}
tok.sv.len++;
switch (ch) {
case 'b':
tok.base = m = 2;
break;
case 'o':
tok.base = m = 8;
break;
case 'd':
/* Implicitly base-10 already */
break;
case 'x':
/* m = 22 because A–F can be both upper- or lowercase */
tok.base = 16;
m = 22;
break;
default:
if (!ISDIGIT(ch))
DIE_AT_POS_WITH_CODE2(tok.sv, E_BASE);
}
}
out:
/* +1 to support the digit separator */
tok.sv.len += off = u8bspn(sv->p, sv->len, NUMCHARS, m + 1);
U8MOV(sv, off);
} else if (ch == '.' || ch == '_' || rprop_is_xids(ch)) {
tok.kind = T_IDENT;
if (ch == '.') {
tok.sv.len += w = u8next(&ch, &sv->p, &sv->len);
if (!w || rprop_is_pat_ws(ch))
DIE_AT_POS_WITH_CODE2(tok.sv, E_IDENTLOST);
if (ch != '_' && !rprop_is_xids(ch)) {
U8MOV(&tok.sv, 1);
DIE_AT_POS_WITH_CODE2(tok.sv, E_IDENTSCHAR);
}
}
while (w = u8next(&ch, &sv->p, &sv->len)) {
if (ch == ':' || rprop_is_pat_ws(ch)) {
U8MOV(sv, -w);
break;
}
if (!rprop_is_xidc(ch)) {
struct u8view hl = {
.p = sv->p - w,
.len = w,
};
DIE_AT_POS_WITH_CODE2(hl, E_IDENTCCHAR);
}
tok.sv.len += w;
}
} else if (ch == '"') {
tok.kind = T_STRING;
while (w = u8next(&ch, &sv->p, &sv->len)) {
tok.sv.len += w;
if (ch == '"')
goto found;
}
DIE_AT_POS_WITH_CODE2(tok.sv, E_UNTERMINATED);
found:
} else if (ch == ':') {
tok.kind = T_COLON;
} else if (ch == ';') {
goto end;
} else {
struct u8view hl = {.p = sv->p - w, .len = w};
DIE_AT_POS_WITH_CODE2(hl, E_EXTRA);
}
/* The colon is the only token that isn’t whitespace separated */
if (ch != ':' && sv->len) {
w = u8next(&ch, &sv->p, &sv->len);
if (!w || !rprop_is_pat_ws(ch)) {
struct u8view hl = {.p = sv->p - w, .len = w};
DIE_AT_POS_WITH_CODE2(hl, E_EXTRA);
}
}
dapush(toks, tok);
}
end:;
tok = (struct token){
.kind = T_EOL,
.sv.p = sv->p,
.sv.len = 0,
};
dapush(toks, tok);
}
#undef DIE_AT_POS_WITH_CODE2
bool
skipws(struct u8view *sv)
{
rune ch;
if (!sv->len)
return false;
for (int w = u8tor_uc(&ch, sv->p); rprop_is_pat_ws(ch);
w = u8tor_uc(&ch, sv->p))
{
U8MOV(sv, w);
if (!sv->len)
return false;
}
return true;
}
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