interpret/src/interpret.re_c.c

120 lines
3.2 KiB
C

/** @license 2022 Neil Edelman, distributed under the terms of the
[MIT License](https://opensource.org/licenses/MIT).
Lexer for journal entries.
@std C89/90 */
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#include <limits.h>
#include <errno.h>
/* This defines `enum condition`. */
/*!types:re2c*/
enum symbol { END, TEXT, BANG, WHITE, MAP };
/** scanner reads a file and extracts semantic information. Valid to access
only while underlying pointers do not change. */
struct scanner {
/* `re2c` variables; these point directly into `buffer`. */
const char *marker, *ctx_marker, *from, *cursor;
/* Weird `c2re` stuff: these fields have to come after when >5? */
const char *label, *buffer, *s0, *s1;
enum condition condition;
enum symbol symbol;
size_t line;
int ws_before;
};
/*!re2c
re2c:yyfill:enable = 0;
re2c:flags:tags = 1;
re2c:define:YYCTYPE = char;
re2c:define:YYCURSOR = s->cursor;
re2c:define:YYMARKER = s->marker;
re2c:define:YYCTXMARKER = s->ctx_marker;
re2c:define:YYCONDTYPE = 'condition';
re2c:define:YYGETCONDITION = 's->condition';
re2c:define:YYGETCONDITION:naked = 1;
re2c:define:YYSETCONDITION = 's->condition = @@;';
re2c:define:YYSETCONDITION:naked = 1;
// Eof is marked by null when preparing files for lexing.
// Mutually exclusive; only !, [, are not covered.
end = "\x00";
newline = "\n" | "\r" "\n"?;
ws = [ \t\v\f];
glyph = [^ \t\n\r\v\f![\x00];
glyphs = glyph+;
// inside the block
decimal = [1-9][0-9]*;
number = ([1-9][0-9]* | [0])? "." [0-9]+ | [1-9][0-9]* | [0];
id = [a-zA-Z_][a-zA-Z_\-0-9]{0,63};
*/
static int lex(struct scanner *const s) {
const char *s0, *s1;
/*!stags:re2c format = 'const char *@@;\n'; */
s->ws_before = 0;
scan:
/*!re2c
<text> end { return s->symbol = END, 1; }
// fixme: paragraphs.
<text> newline { s->line++; s->ws_before = 1; goto scan; }
<text> ws+ { s->ws_before = 1; goto scan; }
<text> @s0 glyph+ @s1 { s->s0 = s0, s->s1 = s1;
return s->symbol = TEXT, 1; }
<text> @s0 "!" @s1 { s->s0 = s0, s->s1 = s1;
return s->symbol = BANG, 1; }
<text> "![" :=> image
<text> "[" :=> command
<image> * { return 0; }
<image> ws* "osm" ws* "](geo:" @s0 number "," @s1 number ")" {
s->condition = yyctext;
s->s0 = s0, s->s1 = s1;
printf("Got a map.\n");
return 1;
}
<command> * { return 0; }
*/
}
static int parse_uint(const char *s, const char *e, unsigned *u) {
uint32_t n = 0;
for ( ; s < e; ++s) {
unsigned digit = (unsigned)(*s - '0');
assert(digit < 10);
if(n > (UINT_MAX - digit) / 10) return errno = ERANGE, 0; /* check */
n = n * 10 + digit;
}
*u = n;
return 1;
}
static int parse_double(const char *s0, const char *s1, double *d) {
char *finish;
assert(d && s0 && s0 < s1);
*d = strtod(s0, &finish);
return !errno && ((finish == s1) || (errno = EDOM, 0));
}
#include <unistd.h> /* chdir (POSIX, not ANSI) */
#include <sys/types.h> /* mode_t (umask) */
#include <sys/stat.h> /* umask */
int main(int argc, char **argv) {
int success = EXIT_FAILURE;
if(argc != 2) { fprintf(stderr, "Needs journal location.\n"
"(should contain <year>/<month>/<day>.txt)\n"); goto finally; }
if(chdir(argv[1]) == -1) goto catch; /* Go to journal. */
{ success = EXIT_SUCCESS; goto finally; }
catch:
perror("interpret");
finally:
return EXIT_FAILURE;
}