Initial commit
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75ff8091aa
GPG Key ID:
B715679E3A361BE6
7
Makefile
Normal file
7
Makefile
Normal file
@ -0,0 +1,7 @@
|
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CFLAGS = -std=gnu99 -Wall
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all: ell
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ell: ell.c
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$(CC) $(CFLAGS) $< -o $@
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clean:
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rm ell
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.PHONY: all clean
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913
ell.c
Executable file
913
ell.c
Executable file
@ -0,0 +1,913 @@
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#define _XOPEN_SOURCE 500
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <ctype.h>
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#include <errno.h>
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#include <stdarg.h>
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#include <assert.h>
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#include <time.h>
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#include <stdbool.h>
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#include <strings.h>
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#include <math.h>
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#if defined __GNUC__
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#define ATTRIBUTE_PRINTF(x, y) __attribute__ ((format (printf, x, y)))
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#else // ! __GNUC__
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#define ATTRIBUTE_PRINTF(x, y)
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#endif // ! __GNUC__
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#define N_ELEMENTS(a) (sizeof (a) / sizeof ((a)[0]))
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// --- Utilities ---------------------------------------------------------------
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static char *format (const char *format, ...) ATTRIBUTE_PRINTF (1, 2);
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static char *
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strdup_vprintf (const char *format, va_list ap) {
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va_list aq;
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va_copy (aq, ap);
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int size = vsnprintf (NULL, 0, format, aq);
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va_end (aq);
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||||
if (size < 0)
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return NULL;
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||||
|
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char buf[size + 1];
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||||
size = vsnprintf (buf, sizeof buf, format, ap);
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||||
if (size < 0)
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||||
return NULL;
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||||
|
||||
return strdup (buf);
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}
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|
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static char *
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format (const char *format, ...) {
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va_list ap;
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va_start (ap, format);
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char *result = strdup_vprintf (format, ap);
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va_end (ap);
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return result;
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}
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||||
|
||||
// --- Generic buffer ----------------------------------------------------------
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struct buffer {
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char *s; ///< Buffer data
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size_t alloc; ///< Number of bytes allocated
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size_t len; ///< Number of bytes used
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bool memory_failure; ///< Memory allocation failed
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};
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||||
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||||
#define BUFFER_INITIALIZER { NULL, 0, 0, false }
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|
||||
static bool
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||||
buffer_append (struct buffer *self, const void *s, size_t n) {
|
||||
if (self->memory_failure)
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||||
return false;
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||||
|
||||
if (!self->s)
|
||||
self->s = malloc (self->alloc = 8);
|
||||
while (self->len + n > self->alloc)
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||||
self->s = realloc (self->s, self->alloc <<= 1);
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||||
|
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if (!self->s) {
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||||
self->memory_failure = true;
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return false;
|
||||
}
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||||
|
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memcpy (self->s + self->len, s, n);
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self->len += n;
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return true;
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||||
}
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|
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inline static bool
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buffer_append_c (struct buffer *self, char c) {
|
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return buffer_append (self, &c, 1);
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||||
}
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||||
|
||||
// --- Data types --------------------------------------------------------------
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||||
|
||||
enum item_type { ITEM_STRING, ITEM_LIST };
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||||
|
||||
struct item {
|
||||
enum item_type type; ///< The type of this object
|
||||
struct item *next; ///< Next item on the list/stack
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||||
|
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struct item *head; ///< The head of the list
|
||||
size_t len; ///< Length of the string (sans '\0')
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||||
char value[]; ///< The null-terminated string value
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};
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|
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const char *
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||||
item_type_to_str (enum item_type type) {
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||||
switch (type) {
|
||||
case ITEM_STRING: return "string";
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case ITEM_LIST: return "list";
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}
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||||
abort ();
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}
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|
||||
// --- Item management ---------------------------------------------------------
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static void item_free_list (struct item *);
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static struct item *new_clone_list (const struct item *);
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static void
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item_free (struct item *item) {
|
||||
if (item->type == ITEM_LIST)
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item_free_list (get_list (item));
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||||
free (item);
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}
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||||
|
||||
static void
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item_free_list (struct item *item) {
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||||
while (item) {
|
||||
struct item *link = item;
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||||
item = item->next;
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item_free (link);
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}
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}
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||||
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||||
static struct item *
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new_clone (const struct item *item) {
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||||
size_t size = sizeof *item;
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||||
if (item->type == ITEM_STRING)
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size += item->len + 1;
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||||
|
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struct item *clone = malloc (size);
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if (!clone)
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||||
return NULL;
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||||
|
||||
memcpy (clone, item, size);
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||||
if (item->type == ITEM_LIST) {
|
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if (clone->head && !(clone->head = new_clone_list (clone->head))) {
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free (clone);
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return NULL;
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}
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}
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clone->next = NULL;
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return clone;
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}
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||||
|
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static struct item *
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new_clone_list (const struct item *item) {
|
||||
struct item *head = NULL, *clone;
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||||
for (struct item **out = &head; item; item = item->next) {
|
||||
if (!(clone = *out = new_clone (item))) {
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item_free_list (head);
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return NULL;
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}
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clone->next = NULL;
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out = &clone->next;
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}
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return head;
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}
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static struct item *
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new_string (const char *s, ssize_t len) {
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if (len < 0)
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||||
len = strlen (s);
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struct item *item = calloc (1, sizeof *item + len + 1);
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||||
if (!item)
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return NULL;
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||||
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item->type = ITEM_STRING;
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item->len = len;
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||||
memcpy (item->value, s, len);
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||||
item->value[len] = '\0';
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return item;
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}
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||||
|
||||
static struct item *
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||||
new_list (struct item *head) {
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struct item *item = calloc (1, sizeof *item);
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||||
if (!item)
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||||
return NULL;
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||||
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item->type = ITEM_LIST;
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||||
item->head = head;
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||||
return item;
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||||
}
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||||
|
||||
// --- Lexer -------------------------------------------------------------------
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||||
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||||
enum token {
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||||
T_ABORT, ///< EOF or error
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T_LPAREN, ///< Left parenthesis
|
||||
T_RPAREN, ///< Right parenthesis
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||||
T_LBRACKET, ///< Left bracket
|
||||
T_RBRACKET, ///< Right bracket
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||||
T_LBRACE, ///< Left curly bracket
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||||
T_RBRACE, ///< Right curly bracket
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||||
T_STRING, ///< Everything else that's not space
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||||
T_NEWLINE, ///< New line
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||||
T_AT ///< At symbol
|
||||
};
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||||
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||||
static const char *
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||||
token_name (enum token token) {
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||||
switch (token) {
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||||
case T_ABORT: return "end of input";
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case T_LPAREN: return "left parenthesis";
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case T_RPAREN: return "right parenthesis";
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case T_LBRACKET: return "left bracket";
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case T_RBRACKET: return "right bracket";
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case T_LBRACE: return "left brace";
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case T_RBRACE: return "right brace";
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case T_STRING: return "string";
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||||
case T_NEWLINE: return "newline";
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||||
case T_AT: return "at symbol";
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||||
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||||
default:
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abort ();
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||||
return NULL;
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||||
}
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||||
}
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||||
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||||
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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||||
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||||
struct lexer {
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||||
const char *p; ///< Current position in input
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||||
size_t len; ///< How many bytes of input are left
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unsigned line; ///< Current line
|
||||
unsigned column; ///< Current column
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||||
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||||
int64_t integer; ///< Parsed boolean or integer value
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struct str string; ///< Parsed string value
|
||||
};
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||||
/// Input has to be null-terminated anyway
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static void
|
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lexer_init (struct lexer *self, const char *p, size_t len) {
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memset (self, 0, sizeof *self);
|
||||
self->p = p;
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self->len = len;
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||||
str_init (&self->string);
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||||
}
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|
||||
static void
|
||||
lexer_free (struct lexer *self) {
|
||||
str_free (&self->string);
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||||
}
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||||
|
||||
static bool lexer_is_word_char (int c) { return !strchr ("()[]{}\n@#'", c); }
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|
||||
static int
|
||||
lexer_advance (struct lexer *self) {
|
||||
int c = *self->p++;
|
||||
if (c == '\n') {
|
||||
self->column = 0;
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self->line++;
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} else
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self->column++;
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||||
|
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self->len--;
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return c;
|
||||
}
|
||||
|
||||
static void lexer_error (struct lexer *self,
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struct error **e, const char *format, ...) ATTRIBUTE_PRINTF (3, 4);
|
||||
|
||||
static void
|
||||
lexer_error (struct lexer *self, struct error **e, const char *format, ...) {
|
||||
struct str description;
|
||||
str_init (&description);
|
||||
|
||||
va_list ap;
|
||||
va_start (ap, format);
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||||
str_append_vprintf (&description, format, ap);
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||||
va_end (ap);
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||||
|
||||
if (self->report_line)
|
||||
error_set (e, "near line %u, column %u: %s",
|
||||
self->line + 1, self->column + 1, description.str);
|
||||
else if (self->len)
|
||||
error_set (e, "near character %u: %s",
|
||||
self->column + 1, description.str);
|
||||
else
|
||||
error_set (e, "near end: %s", description.str);
|
||||
|
||||
str_free (&description);
|
||||
}
|
||||
|
||||
static bool
|
||||
lexer_hexa_escape (struct lexer *self, struct str *output) {
|
||||
int i;
|
||||
unsigned char code = 0;
|
||||
|
||||
for (i = 0; self->len && i < 2; i++) {
|
||||
unsigned char c = tolower (*self->p);
|
||||
if (c >= '0' && c <= '9')
|
||||
code = (code << 4) | (c - '0');
|
||||
else if (c >= 'a' && c <= 'f')
|
||||
code = (code << 4) | (c - 'a' + 10);
|
||||
else
|
||||
break;
|
||||
|
||||
lexer_advance (self);
|
||||
}
|
||||
|
||||
if (!i)
|
||||
return false;
|
||||
|
||||
str_append_c (output, code);
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
lexer_escape_sequence
|
||||
(struct lexer *self, struct str *output, struct error **e) {
|
||||
if (!self->len) {
|
||||
lexer_error (self, e, "premature end of escape sequence");
|
||||
return false;
|
||||
}
|
||||
|
||||
unsigned char c;
|
||||
switch ((c = *self->p)) {
|
||||
case '"': break;
|
||||
case '\\': break;
|
||||
case 'a': c = '\a'; break;
|
||||
case 'b': c = '\b'; break;
|
||||
case 'f': c = '\f'; break;
|
||||
case 'n': c = '\n'; break;
|
||||
case 'r': c = '\r'; break;
|
||||
case 't': c = '\t'; break;
|
||||
case 'v': c = '\v'; break;
|
||||
|
||||
case 'x':
|
||||
case 'X':
|
||||
lexer_advance (self);
|
||||
if (lexer_hexa_escape (self, output))
|
||||
return true;
|
||||
|
||||
lexer_error (self, e, "invalid hexadecimal escape");
|
||||
return false;
|
||||
|
||||
default:
|
||||
lexer_error (self, e, "unknown escape sequence");
|
||||
return false;
|
||||
}
|
||||
|
||||
str_append_c (output, c);
|
||||
lexer_advance (self);
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
lexer_string (struct lexer *self, struct str *output, struct error **e) {
|
||||
unsigned char c;
|
||||
while (self->len) {
|
||||
if ((c = lexer_advance (self)) == '\'')
|
||||
return true;
|
||||
if (c != '\\')
|
||||
str_append_c (output, c);
|
||||
else if (!lexer_escape_sequence (self, output, e))
|
||||
return false;
|
||||
}
|
||||
lexer_error (self, e, "premature end of string");
|
||||
return false;
|
||||
}
|
||||
|
||||
static enum token
|
||||
lexer_next (struct lexer *self, struct error **e) {
|
||||
// Skip over any whitespace between tokens
|
||||
while (self->len && isspace_ascii (*self->p) && *self->p != '\n')
|
||||
lexer_advance (self);
|
||||
if (!self->len)
|
||||
return T_ABORT;
|
||||
|
||||
switch (*self->p) {
|
||||
case '(': lexer_advance (self); return T_LPAREN;
|
||||
case ')': lexer_advance (self); return T_RPAREN;
|
||||
case '[': lexer_advance (self); return T_LBRACKET;
|
||||
case ']': lexer_advance (self); return T_RBRACKET;
|
||||
case '{': lexer_advance (self); return T_LBRACE;
|
||||
case '}': lexer_advance (self); return T_RBRACE;
|
||||
case '\n': lexer_advance (self); return T_NEWLINE;
|
||||
case '@': lexer_advance (self); return T_AT;
|
||||
|
||||
case '#':
|
||||
// Comments go until newline
|
||||
while (self->len)
|
||||
if (lexer_advance (self) == '\n')
|
||||
return T_NEWLINE;
|
||||
return T_ABORT;
|
||||
|
||||
case '\'':
|
||||
lexer_advance (self);
|
||||
str_reset (&self->string);
|
||||
if (!lexer_string (self, &self->string, e))
|
||||
return T_ABORT;
|
||||
return T_STRING;
|
||||
}
|
||||
|
||||
assert (lexer_is_word_char (*self->p));
|
||||
str_reset (&self->string);
|
||||
do
|
||||
str_append_c (&self->string, lexer_advance (self));
|
||||
while (lexer_is_word_char (*self->p));
|
||||
return T_STRING;
|
||||
}
|
||||
|
||||
// --- Parsing -----------------------------------------------------------------
|
||||
|
||||
#define PARSE_ERROR_TABLE(XX) \
|
||||
XX( OK, NULL ) \
|
||||
XX( EOF, "unexpected end of input" ) \
|
||||
XX( INVALID_HEXA_ESCAPE, "invalid hexadecimal escape sequence" ) \
|
||||
XX( INVALID_ESCAPE, "unrecognized escape sequence" ) \
|
||||
XX( MEMORY, "memory allocation failure" ) \
|
||||
XX( FLOAT_RANGE, "floating point value out of range" ) \
|
||||
XX( INTEGER_RANGE, "integer out of range" ) \
|
||||
XX( INVALID_INPUT, "invalid input" ) \
|
||||
XX( UNEXPECTED_INPUT, "unexpected input" )
|
||||
|
||||
enum tokenizer_error {
|
||||
#define XX(x, y) PARSE_ERROR_ ## x,
|
||||
PARSE_ERROR_TABLE (XX)
|
||||
#undef XX
|
||||
PARSE_ERROR_COUNT
|
||||
};
|
||||
|
||||
struct tokenizer {
|
||||
const char *cursor;
|
||||
enum tokenizer_error error;
|
||||
};
|
||||
|
||||
static bool
|
||||
decode_hexa_escape (struct tokenizer *self, struct buffer *buf) {
|
||||
int i;
|
||||
char c, code = 0;
|
||||
|
||||
for (i = 0; i < 2; i++) {
|
||||
c = tolower (*self->cursor);
|
||||
if (c >= '0' && c <= '9')
|
||||
code = (code << 4) | (c - '0');
|
||||
else if (c >= 'a' && c <= 'f')
|
||||
code = (code << 4) | (c - 'a' + 10);
|
||||
else
|
||||
break;
|
||||
|
||||
self->cursor++;
|
||||
}
|
||||
|
||||
if (!i)
|
||||
return false;
|
||||
|
||||
buffer_append_c (buf, code);
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
decode_escape_sequence (struct tokenizer *self, struct buffer *buf) {
|
||||
// Support some basic escape sequences from the C language
|
||||
char c;
|
||||
switch ((c = *self->cursor)) {
|
||||
case '\0':
|
||||
self->error = PARSE_ERROR_EOF;
|
||||
return false;
|
||||
case 'x':
|
||||
case 'X':
|
||||
self->cursor++;
|
||||
if (decode_hexa_escape (self, buf))
|
||||
return true;
|
||||
|
||||
self->error = PARSE_ERROR_INVALID_HEXA_ESCAPE;
|
||||
return false;
|
||||
default:
|
||||
self->cursor++;
|
||||
const char *from = "abfnrtv\"\\", *to = "\a\b\f\n\r\t\v\"\\", *x;
|
||||
if ((x = strchr (from, c))) {
|
||||
buffer_append_c (buf, to[x - from]);
|
||||
return true;
|
||||
}
|
||||
self->error = PARSE_ERROR_INVALID_ESCAPE;
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
static struct item *
|
||||
parse_string (struct tokenizer *self) {
|
||||
struct buffer buf = BUFFER_INITIALIZER;
|
||||
struct item *item = NULL;
|
||||
char c;
|
||||
|
||||
while (true)
|
||||
switch ((c = *self->cursor++)) {
|
||||
case '\0':
|
||||
self->cursor--;
|
||||
self->error = PARSE_ERROR_EOF;
|
||||
goto end;
|
||||
case '"':
|
||||
if (buf.memory_failure
|
||||
|| !(item = new_string (buf.s, buf.len)))
|
||||
self->error = PARSE_ERROR_MEMORY;
|
||||
goto end;
|
||||
case '\\':
|
||||
if (decode_escape_sequence (self, &buf))
|
||||
break;
|
||||
goto end;
|
||||
default:
|
||||
buffer_append_c (&buf, c);
|
||||
}
|
||||
|
||||
end:
|
||||
free (buf.s);
|
||||
return item;
|
||||
}
|
||||
|
||||
static struct item *
|
||||
parse_word (struct tokenizer *self) {
|
||||
struct buffer buf = BUFFER_INITIALIZER;
|
||||
struct item *item = NULL;
|
||||
char c;
|
||||
|
||||
// Here we accept almost anything that doesn't break the grammar
|
||||
while (!strchr (" []\"", (c = *self->cursor++)) && (unsigned char) c > ' ')
|
||||
buffer_append_c (&buf, c);
|
||||
self->cursor--;
|
||||
|
||||
if (buf.memory_failure)
|
||||
self->error = PARSE_ERROR_MEMORY;
|
||||
else if (!buf.len)
|
||||
self->error = PARSE_ERROR_INVALID_INPUT;
|
||||
else if (!(item = new_word (buf.s, buf.len)))
|
||||
self->error = PARSE_ERROR_MEMORY;
|
||||
|
||||
free (buf.s);
|
||||
return item;
|
||||
}
|
||||
|
||||
static struct item *parse_item_list (struct tokenizer *);
|
||||
|
||||
static struct item *
|
||||
parse_list (struct tokenizer *self) {
|
||||
struct item *list = parse_item_list (self);
|
||||
if (self->error) {
|
||||
assert (list == NULL);
|
||||
return NULL;
|
||||
}
|
||||
if (!*self->cursor) {
|
||||
self->error = PARSE_ERROR_EOF;
|
||||
item_free_list (list);
|
||||
return NULL;
|
||||
}
|
||||
assert (*self->cursor == ']');
|
||||
self->cursor++;
|
||||
return new_list (list);
|
||||
}
|
||||
|
||||
static struct item *
|
||||
parse_item (struct tokenizer *self) {
|
||||
char c;
|
||||
switch ((c = *self->cursor++)) {
|
||||
case '[': return parse_list (self);
|
||||
case '"': return parse_string (self);
|
||||
default:;
|
||||
}
|
||||
|
||||
self->cursor--;
|
||||
return parse_word (self);
|
||||
}
|
||||
|
||||
static struct item *
|
||||
parse_item_list (struct tokenizer *self) {
|
||||
struct item *head = NULL;
|
||||
struct item **tail = &head;
|
||||
|
||||
char c;
|
||||
bool expected = true;
|
||||
while ((c = *self->cursor) && c != ']') {
|
||||
if (isspace (c)) {
|
||||
self->cursor++;
|
||||
expected = true;
|
||||
continue;
|
||||
} else if (!expected) {
|
||||
self->error = PARSE_ERROR_UNEXPECTED_INPUT;
|
||||
goto fail;
|
||||
}
|
||||
|
||||
if (!(*tail = parse_item (self)))
|
||||
goto fail;
|
||||
tail = &(*tail)->next;
|
||||
expected = false;
|
||||
}
|
||||
return head;
|
||||
|
||||
fail:
|
||||
item_free_list (head);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static struct item *
|
||||
parse (const char *s, const char **error) {
|
||||
struct tokenizer self = { .cursor = s, .error = PARSE_ERROR_OK };
|
||||
struct item *list = parse_item_list (&self);
|
||||
if (!self.error && *self.cursor != '\0') {
|
||||
self.error = PARSE_ERROR_UNEXPECTED_INPUT;
|
||||
item_free_list (list);
|
||||
list = NULL;
|
||||
}
|
||||
|
||||
#define XX(x, y) y,
|
||||
static const char *strings[PARSE_ERROR_COUNT] =
|
||||
{ PARSE_ERROR_TABLE (XX) };
|
||||
#undef XX
|
||||
|
||||
static char error_buf[128];
|
||||
if (self.error && error) {
|
||||
snprintf (error_buf, sizeof error_buf, "at character %d: %s",
|
||||
(int) (self.cursor - s) + 1, strings[self.error]);
|
||||
*error = error_buf;
|
||||
}
|
||||
return list;
|
||||
}
|
||||
|
||||
// --- Runtime -----------------------------------------------------------------
|
||||
|
||||
struct context {
|
||||
struct item *stack; ///< The current top of the stack
|
||||
size_t stack_size; ///< Number of items on the stack
|
||||
|
||||
char *error; ///< Error information
|
||||
bool error_is_fatal; ///< Whether the error can be catched
|
||||
bool memory_failure; ///< Memory allocation failure
|
||||
|
||||
void *user_data; ///< User data
|
||||
};
|
||||
|
||||
/// Internal handler for a function
|
||||
typedef bool (*handler_fn) (struct context *);
|
||||
|
||||
struct fn {
|
||||
struct fn *next; ///< The next link in the chain
|
||||
|
||||
handler_fn handler; ///< Internal C handler, or NULL
|
||||
struct item *script; ///< Alternatively runtime code
|
||||
char name[]; ///< The name of the function
|
||||
};
|
||||
|
||||
struct fn *g_functions; ///< Maps words to functions
|
||||
|
||||
static void
|
||||
context_init (struct context *ctx) {
|
||||
ctx->stack = NULL;
|
||||
ctx->stack_size = 0;
|
||||
|
||||
ctx->error = NULL;
|
||||
ctx->error_is_fatal = false;
|
||||
ctx->memory_failure = false;
|
||||
|
||||
ctx->user_data = NULL;
|
||||
}
|
||||
|
||||
static void
|
||||
context_free (struct context *ctx) {
|
||||
item_free_list (ctx->stack);
|
||||
ctx->stack = NULL;
|
||||
|
||||
free (ctx->error);
|
||||
ctx->error = NULL;
|
||||
}
|
||||
|
||||
static bool
|
||||
set_error (struct context *ctx, const char *format, ...) {
|
||||
free (ctx->error);
|
||||
|
||||
va_list ap;
|
||||
va_start (ap, format);
|
||||
ctx->error = strdup_vprintf (format, ap);
|
||||
va_end (ap);
|
||||
|
||||
if (!ctx->error)
|
||||
ctx->memory_failure = true;
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool
|
||||
push (struct context *ctx, struct item *item) {
|
||||
// The `item' is typically a result from new_<type>(), thus when it is null,
|
||||
// that function must have failed. This is a shortcut for convenience.
|
||||
if (!item) {
|
||||
ctx->memory_failure = true;
|
||||
return false;
|
||||
}
|
||||
|
||||
assert (item->next == NULL);
|
||||
item->next = ctx->stack;
|
||||
ctx->stack = item;
|
||||
ctx->stack_size++;
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool execute (struct context *, struct item *);
|
||||
|
||||
static bool
|
||||
call_function (struct context *ctx, const char *name) {
|
||||
struct fn *iter;
|
||||
for (iter = g_functions; iter; iter = iter->next)
|
||||
if (!strcmp (name, iter->name))
|
||||
goto found;
|
||||
return set_error (ctx, "unknown function: %s", name);
|
||||
|
||||
found:
|
||||
if (iter->handler
|
||||
? iter->handler (ctx)
|
||||
: execute (ctx, iter->script))
|
||||
return true;
|
||||
|
||||
// In this case, `error' is NULL
|
||||
if (ctx->memory_failure)
|
||||
return false;
|
||||
|
||||
// This creates some form of a stack trace
|
||||
char *tmp = ctx->error;
|
||||
ctx->error = NULL;
|
||||
set_error (ctx, "%s -> %s", name, tmp);
|
||||
free (tmp);
|
||||
return false;
|
||||
}
|
||||
|
||||
static void
|
||||
free_function (struct fn *fn) {
|
||||
item_free_list (fn->script);
|
||||
free (fn);
|
||||
}
|
||||
|
||||
static void
|
||||
unregister_function (const char *name) {
|
||||
for (struct fn **iter = &g_functions; *iter; iter = &(*iter)->next)
|
||||
if (!strcmp ((*iter)->name, name)) {
|
||||
struct fn *tmp = *iter;
|
||||
*iter = tmp->next;
|
||||
free_function (tmp);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
static struct fn *
|
||||
prepend_new_fn (const char *name) {
|
||||
struct fn *fn = calloc (1, sizeof *fn + strlen (name) + 1);
|
||||
if (!fn)
|
||||
return NULL;
|
||||
|
||||
strcpy (fn->name, name);
|
||||
fn->next = g_functions;
|
||||
return g_functions = fn;
|
||||
}
|
||||
|
||||
static bool
|
||||
register_handler (const char *name, handler_fn handler) {
|
||||
unregister_function (name);
|
||||
struct fn *fn = prepend_new_fn (name);
|
||||
if (!fn)
|
||||
return false;
|
||||
fn->handler = handler;
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
register_script (const char *name, struct item *script) {
|
||||
unregister_function (name);
|
||||
struct fn *fn = prepend_new_fn (name);
|
||||
if (!fn)
|
||||
return false;
|
||||
fn->script = script;
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
execute (struct context *ctx, struct item *script) {
|
||||
for (; script; script = script->next) {
|
||||
if (script->type != ITEM_STRING) {
|
||||
if (!push (ctx, new_clone (script)))
|
||||
return false;
|
||||
}
|
||||
else if (!call_function (ctx, get_word (script)))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
// --- Runtime library ---------------------------------------------------------
|
||||
|
||||
#define defn(name) static bool name (struct context *ctx)
|
||||
|
||||
static bool
|
||||
init_runtime_library_scripts (void) {
|
||||
bool ok = true;
|
||||
|
||||
// It's much cheaper (and more fun) to define functions in terms of other
|
||||
// ones. The "unit tests" serve a secondary purpose of showing the usage.
|
||||
struct script {
|
||||
const char *name; ///< Name of the function
|
||||
const char *definition; ///< The defining script
|
||||
} scripts[] = {
|
||||
{ "greet", "print (.. 'hello ' (.. @1))" },
|
||||
};
|
||||
|
||||
for (size_t i = 0; i < N_ELEMENTS (scripts); i++) {
|
||||
const char *error = NULL;
|
||||
struct item *script = parse (scripts[i].definition, &error);
|
||||
if (error) {
|
||||
printf ("error parsing internal script `%s': %s\n",
|
||||
scripts[i].definition, error);
|
||||
ok = false;
|
||||
} else
|
||||
ok &= register_script (scripts[i].name, script);
|
||||
}
|
||||
return ok;
|
||||
}
|
||||
|
||||
defn (fn_print) {
|
||||
check_stack (1);
|
||||
struct item *item = pop (ctx);
|
||||
struct user_info *info = ctx->user_data;
|
||||
|
||||
struct buffer buf = BUFFER_INITIALIZER;
|
||||
item_to_str (item, &buf);
|
||||
item_free (item);
|
||||
buffer_append_c (&buf, '\0');
|
||||
if (buf.memory_failure) {
|
||||
ctx->memory_failure = true;
|
||||
return false;
|
||||
}
|
||||
|
||||
printf ("%s\n", buf.s);
|
||||
free (buf.s);
|
||||
return true;
|
||||
}
|
||||
|
||||
defn (fn_concatenate) {
|
||||
// TODO: concatenate string arguments, error on list
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool
|
||||
init_runtime_library (void)
|
||||
{
|
||||
return register_handler ("..", fn_concatenate);
|
||||
&& register_handler ("print", fn_print);
|
||||
&& init_runtime_library_scripts ();
|
||||
}
|
||||
|
||||
static void
|
||||
free_runtime_library (void) {
|
||||
struct fn *next, *iter;
|
||||
for (iter = g_functions; iter; iter = next) {
|
||||
next = iter->next;
|
||||
free_function (iter);
|
||||
}
|
||||
}
|
||||
|
||||
// --- Main --------------------------------------------------------------------
|
||||
|
||||
static void
|
||||
process_message (const char *msg) {
|
||||
// Finally parse and execute the macro
|
||||
const char *error = NULL;
|
||||
struct item *script = parse (msg, &error);
|
||||
if (error) {
|
||||
printf ("%s: %s\r\n", "parse error", error);
|
||||
goto end;
|
||||
}
|
||||
|
||||
struct context ctx;
|
||||
context_init (&ctx);
|
||||
ctx.user_data = &info;
|
||||
execute (&ctx, script);
|
||||
item_free_list (script);
|
||||
|
||||
const char *failure = NULL;
|
||||
if (ctx.memory_failure)
|
||||
failure = "memory allocation failure";
|
||||
else if (ctx.error)
|
||||
failure = ctx.error;
|
||||
if (failure)
|
||||
printf ("%s: %s\r\n", "runtime error", failure);
|
||||
context_free (&ctx);
|
||||
end:
|
||||
free (msg_ctx_quote);
|
||||
}
|
||||
|
||||
int
|
||||
main (int argc, char *argv[]) {
|
||||
freopen (NULL, "rb", stdin); setvbuf (stdin, NULL, _IOLBF, BUFSIZ);
|
||||
freopen (NULL, "wb", stdout); setvbuf (stdout, NULL, _IOLBF, BUFSIZ);
|
||||
|
||||
if (!init_runtime_library ()
|
||||
|| !register_handler (".", fn_dot))
|
||||
printf ("%s\n", "runtime library initialization failed");
|
||||
|
||||
// TODO: load the entirety of stdin and execute it
|
||||
process_message ("print 'hello world\n'");
|
||||
|
||||
free_runtime_library ();
|
||||
return 0;
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user