picrin/read.c

934 lines
19 KiB
C
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2014-08-25 00:38:09 -04:00
/**
* See Copyright Notice in picrin.h
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include "picrin.h"
#include "picrin/read.h"
#include "picrin/error.h"
#include "picrin/pair.h"
#include "picrin/string.h"
#include "picrin/vector.h"
#include "picrin/blob.h"
#include "picrin/port.h"
#include "picrin/proc.h"
static pic_value read(pic_state *pic, struct pic_port *port, int c);
static pic_value read_nullable(pic_state *pic, struct pic_port *port, int c);
static noreturn void
read_error(pic_state *pic, const char *msg)
{
pic_throw(pic, PIC_ERROR_READ, msg, pic_nil_value());
}
static int
skip(struct pic_port *port, int c)
{
while (isspace(c)) {
c = xfgetc(port->file);
}
return c;
}
static int
next(struct pic_port *port)
{
return xfgetc(port->file);
}
static int
peek(struct pic_port *port)
{
int c;
xungetc((c = xfgetc(port->file)), port->file);
return c;
}
static bool
expect(struct pic_port *port, const char *str)
{
int c;
while ((c = (int)*str++) != 0) {
if (c != peek(port))
return false;
next(port);
}
return true;
}
static bool
isdelim(int c)
{
return c == EOF || strchr("();,|\" \t\n\r", c) != NULL; /* ignores "#", "'" */
}
static bool
strcaseeq(const char *s1, const char *s2)
{
char a, b;
while ((a = *s1++) * (b = *s2++)) {
if (tolower(a) != tolower(b))
return false;
}
return a == b;
}
static pic_value
read_comment(pic_state *pic, struct pic_port *port, const char *str)
{
int c;
UNUSED(pic);
UNUSED(str);
do {
c = next(port);
} while (! (c == EOF || c == '\n'));
return pic_undef_value();
}
static pic_value
read_block_comment(pic_state *pic, struct pic_port *port, const char *str)
{
int x, y;
int i = 1;
UNUSED(pic);
UNUSED(str);
y = next(port);
while (y != EOF && i > 0) {
x = y;
y = next(port);
if (x == '|' && y == '#') {
i--;
}
if (x == '#' && y == '|') {
i++;
}
}
return pic_undef_value();
}
static pic_value
read_datum_comment(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(str);
read(pic, port, next(port));
return pic_undef_value();
}
static pic_value
read_directive(pic_state *pic, struct pic_port *port, const char *str)
{
switch (peek(port)) {
case 'n':
if (expect(port, "no-fold-case")) {
pic->reader->typecase = PIC_CASE_DEFAULT;
return pic_undef_value();
}
break;
case 'f':
if (expect(port, "fold-case")) {
pic->reader->typecase = PIC_CASE_FOLD;
return pic_undef_value();
}
break;
}
return read_comment(pic, port, str);
}
static pic_value
read_eval(pic_state *pic, struct pic_port *port, const char *str)
{
pic_value form;
UNUSED(str);
form = read(pic, port, next(port));
return pic_eval(pic, form, pic->lib);
}
static pic_value
read_quote(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(str);
return pic_list2(pic, pic_sym_value(pic->sQUOTE), read(pic, port, next(port)));
}
static pic_value
read_quasiquote(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(str);
return pic_list2(pic, pic_sym_value(pic->sQUASIQUOTE), read(pic, port, next(port)));
}
static pic_value
read_unquote(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(str);
return pic_list2(pic, pic_sym_value(pic->sUNQUOTE), read(pic, port, next(port)));
}
static pic_value
read_unquote_splicing(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(str);
return pic_list2(pic, pic_sym_value(pic->sUNQUOTE_SPLICING), read(pic, port, next(port)));
}
static pic_value
read_symbol(pic_state *pic, struct pic_port *port, const char *str)
{
size_t len, i;
char *buf;
pic_sym sym;
int c;
len = strlen(str);
buf = pic_calloc(pic, 1, len + 1);
for (i = 0; i < len; ++i) {
if (pic->reader->typecase == PIC_CASE_FOLD) {
buf[i] = tolower(str[i]);
} else {
buf[i] = str[i];
}
}
while (! isdelim(peek(port))) {
c = next(port);
if (pic->reader->typecase == PIC_CASE_FOLD) {
c = tolower(c);
}
len += 1;
buf = pic_realloc(pic, buf, len + 1);
buf[len - 1] = c;
}
sym = pic_intern(pic, buf, len);
pic_free(pic, buf);
return pic_sym_value(sym);
}
static size_t
read_uinteger(pic_state *pic, struct pic_port *port, int c, char buf[])
{
size_t i = 0;
if (! isdigit(c)) {
read_error(pic, "expected one or more digits");
}
buf[i++] = c;
while (isdigit(c = peek(port))) {
buf[i++] = next(port);
}
buf[i] = '\0';
return i;
}
static size_t
read_suffix(pic_state *pic, struct pic_port *port, char buf[])
{
size_t i = 0;
int c;
c = peek(port);
if (c != 'e' && c != 'E') {
return i;
}
buf[i++] = next(port);
switch ((c = next(port))) {
case '-':
case '+':
buf[i++] = c;
c = next(port);
default:
return i + read_uinteger(pic, port, c, buf + i);
}
}
static pic_value
read_unsigned(pic_state *pic, struct pic_port *port, int c)
{
char buf[256];
size_t i;
i = read_uinteger(pic, port, c, buf);
switch (peek(port)) {
case '.':
buf[i++] = next(port);
i += read_uinteger(pic, port, next(port), buf + i);
read_suffix(pic, port, buf + i);
return pic_float_value(atof(buf));
default:
read_suffix(pic, port, buf + i);
return pic_int_value((int)atof(buf));
}
}
static pic_value
read_number(pic_state *pic, struct pic_port *port, const char *str)
{
return read_unsigned(pic, port, str[0]);
}
static pic_value
negate(pic_value n)
{
if (pic_int_p(n)) {
return pic_int_value(-pic_int(n));
} else {
return pic_float_value(-pic_float(n));
}
}
static pic_value
read_minus(pic_state *pic, struct pic_port *port, const char *str)
{
pic_value sym;
if (isdigit(peek(port))) {
return negate(read_unsigned(pic, port, next(port)));
}
else {
sym = read_symbol(pic, port, str);
if (strcaseeq(pic_symbol_name(pic, pic_sym(sym)), "-inf.0")) {
return pic_float_value(-INFINITY);
}
if (strcaseeq(pic_symbol_name(pic, pic_sym(sym)), "-nan.0")) {
return pic_float_value(-NAN);
}
return sym;
}
}
static pic_value
read_plus(pic_state *pic, struct pic_port *port, const char *str)
{
pic_value sym;
if (isdigit(peek(port))) {
return read_unsigned(pic, port, next(port));
}
else {
sym = read_symbol(pic, port, str);
if (strcaseeq(pic_symbol_name(pic, pic_sym(sym)), "+inf.0")) {
return pic_float_value(INFINITY);
}
if (strcaseeq(pic_symbol_name(pic, pic_sym(sym)), "+nan.0")) {
return pic_float_value(NAN);
}
return sym;
}
}
static pic_value
read_true(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(pic);
UNUSED(port);
UNUSED(str);
return pic_true_value();
}
static pic_value
read_false(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(pic);
UNUSED(port);
UNUSED(str);
return pic_false_value();
}
static pic_value
read_char(pic_state *pic, struct pic_port *port, const char *str)
{
int c;
UNUSED(str);
c = next(port);
if (! isdelim(peek(port))) {
switch (c) {
default: read_error(pic, "unexpected character after char literal");
case 'a': c = '\a'; if (! expect(port, "lerm")) goto fail; break;
case 'b': c = '\b'; if (! expect(port, "ackspace")) goto fail; break;
case 'd': c = 0x7F; if (! expect(port, "elete")) goto fail; break;
case 'e': c = 0x1B; if (! expect(port, "scape")) goto fail; break;
case 'n':
if ((c = peek(port)) == 'e') {
c = '\n';
if (! expect(port, "ewline"))
goto fail;
} else {
c = '\0';
if (! expect(port, "ull"))
goto fail;
}
break;
case 'r': c = '\r'; if (! expect(port, "eturn")) goto fail; break;
case 's': c = ' '; if (! expect(port, "pace")) goto fail; break;
case 't': c = '\t'; if (! expect(port, "ab")) goto fail; break;
}
}
return pic_char_value(c);
fail:
read_error(pic, "unexpected character while reading character literal");
}
static pic_value
read_string(pic_state *pic, struct pic_port *port, const char *name)
{
int c;
char *buf;
size_t size, cnt;
pic_str *str;
UNUSED(name);
size = 256;
buf = pic_alloc(pic, size);
cnt = 0;
/* TODO: intraline whitespaces */
while ((c = next(port)) != '"') {
if (c == '\\') {
switch (c = next(port)) {
case 'a': c = '\a'; break;
case 'b': c = '\b'; break;
case 't': c = '\t'; break;
case 'n': c = '\n'; break;
case 'r': c = '\r'; break;
}
}
buf[cnt++] = c;
if (cnt >= size) {
buf = pic_realloc(pic, buf, size *= 2);
}
}
buf[cnt] = '\0';
str = pic_str_new(pic, buf, cnt);
pic_free(pic, buf);
return pic_obj_value(str);
}
static pic_value
read_pipe(pic_state *pic, struct pic_port *port, const char *str)
{
char *buf;
size_t size, cnt;
pic_sym sym;
/* Currently supports only ascii chars */
char HEX_BUF[3];
size_t i = 0;
int c;
UNUSED(str);
size = 256;
buf = pic_alloc(pic, size);
cnt = 0;
while ((c = next(port)) != '|') {
if (c == '\\') {
switch ((c = next(port))) {
case 'a': c = '\a'; break;
case 'b': c = '\b'; break;
case 't': c = '\t'; break;
case 'n': c = '\n'; break;
case 'r': c = '\r'; break;
case 'x':
i = 0;
while ((HEX_BUF[i++] = next(port)) != ';') {
if (i >= sizeof HEX_BUF)
read_error(pic, "expected ';'");
}
c = strtol(HEX_BUF, NULL, 16);
break;
}
}
buf[cnt++] = c;
if (cnt >= size) {
buf = pic_realloc(pic, buf, size *= 2);
}
}
buf[cnt] = '\0';
sym = pic_intern_cstr(pic, buf);
pic_free(pic, buf);
return pic_sym_value(sym);
}
static pic_value
read_blob(pic_state *pic, struct pic_port *port, const char *str)
{
int nbits, n, c;
size_t len, i;
char *dat, buf[256];
pic_blob *blob;
UNUSED(str);
nbits = 0;
while (isdigit(c = next(port))) {
nbits = 10 * nbits + c - '0';
}
if (nbits != 8) {
read_error(pic, "unsupported bytevector bit width");
}
if (c != '(') {
read_error(pic, "expected '(' character");
}
len = 0;
dat = NULL;
c = next(port);
while ((c = skip(port, c)) != ')') {
read_uinteger(pic, port, c, buf);
n = atoi(buf);
if (n < 0 || (1 << nbits) <= n) {
read_error(pic, "invalid element in bytevector literal");
}
len += 1;
dat = pic_realloc(pic, dat, len);
dat[len - 1] = n;
c = next(port);
}
blob = pic_blob_new(pic, len);
for (i = 0; i < len; ++i) {
blob->data[i] = dat[i];
}
pic_free(pic, dat);
return pic_obj_value(blob);
}
static pic_value
read_pair(pic_state *pic, struct pic_port *port, const char *str)
{
const int tCLOSE = (str[0] == '(') ? ')' : ']';
pic_value car, cdr;
int c;
retry:
c = skip(port, ' ');
if (c == tCLOSE) {
return pic_nil_value();
}
if (c == '.' && isdelim(peek(port))) {
cdr = read(pic, port, next(port));
closing:
if ((c = skip(port, ' ')) != tCLOSE) {
if (pic_undef_p(read_nullable(pic, port, c))) {
goto closing;
}
read_error(pic, "unmatched parenthesis");
}
return cdr;
}
else {
car = read_nullable(pic, port, c);
if (pic_undef_p(car)) {
goto retry;
}
cdr = read_pair(pic, port, str);
return pic_cons(pic, car, cdr);
}
}
static pic_value
read_vector(pic_state *pic, struct pic_port *port, const char *str)
{
pic_value list;
list = read(pic, port, str[1]);
return pic_obj_value(pic_vec_new_from_list(pic, list));
}
static pic_value
read_label_set(pic_state *pic, struct pic_port *port, int i)
{
pic_value val;
int c;
switch ((c = skip(port, ' '))) {
case '(': case '[':
{
pic_value tmp;
val = pic_cons(pic, pic_none_value(), pic_none_value());
xh_put_int(&pic->reader->labels, i, &val);
tmp = read(pic, port, c);
pic_pair_ptr(val)->car = pic_car(pic, tmp);
pic_pair_ptr(val)->cdr = pic_cdr(pic, tmp);
return val;
}
case '#':
{
bool vect;
if (peek(port) == '(') {
vect = true;
} else {
vect = false;
}
if (vect) {
pic_vec *tmp;
val = pic_obj_value(pic_vec_new(pic, 0));
xh_put_int(&pic->reader->labels, i, &val);
tmp = pic_vec_ptr(read(pic, port, c));
SWAP(pic_value *, tmp->data, pic_vec_ptr(val)->data);
SWAP(size_t, tmp->len, pic_vec_ptr(val)->len);
return val;
}
FALLTHROUGH;
}
default:
{
val = read(pic, port, c);
xh_put_int(&pic->reader->labels, i, &val);
return val;
}
}
}
static pic_value
read_label_ref(pic_state *pic, struct pic_port *port, int i)
{
xh_entry *e;
UNUSED(port);
e = xh_get_int(&pic->reader->labels, i);
if (! e) {
read_error(pic, "label of given index not defined");
}
return xh_val(e, pic_value);
}
static pic_value
read_label(pic_state *pic, struct pic_port *port, const char *str)
{
int i, c;
i = 0;
c = str[1]; /* initial index letter */
do {
i = i * 10 + c;
} while (isdigit(c = next(port)));
if (c == '=') {
return read_label_set(pic, port, i);
}
if (c == '#') {
return read_label_ref(pic, port, i);
}
read_error(pic, "broken label expression");
}
static pic_value
read_unmatch(pic_state *pic, struct pic_port *port, const char *str)
{
UNUSED(port);
UNUSED(str);
read_error(pic, "unmatched parenthesis");
}
static pic_value
read_nullable(pic_state *pic, struct pic_port *port, int c)
{
struct pic_trie *trie = pic->reader->trie;
char buf[128];
size_t i = 0;
pic_str *str;
c = skip(port, c);
if (c == EOF) {
read_error(pic, "unexpected EOF");
}
if (trie->table[c] == NULL) {
read_error(pic, "invalid character at the seeker head");
}
buf[i++] = c;
while (i < sizeof buf) {
trie = trie->table[c];
if ((c = peek(port)) == EOF) {
break;
}
if (trie->table[c] == NULL) {
break;
}
buf[i++] = next(port);
}
if (i == sizeof buf) {
read_error(pic, "too long dispatch string");
}
if (trie->proc == NULL) {
read_error(pic, "no reader registered for current string");
}
str = pic_str_new(pic, buf, i);
return pic_apply2(pic, trie->proc, pic_obj_value(port), pic_obj_value(str));
}
static pic_value
read(pic_state *pic, struct pic_port *port, int c)
{
pic_value val;
retry:
val = read_nullable(pic, port, c);
if (pic_undef_p(val)) {
c = next(port);
goto retry;
}
return val;
}
struct pic_trie *
pic_trie_new(pic_state *pic)
{
struct pic_trie *trie;
trie = pic_alloc(pic, sizeof(struct pic_trie));
trie->proc = NULL;
memset(trie->table, 0, sizeof trie->table);
return trie;
}
void
pic_trie_delete(pic_state *pic, struct pic_trie *trie)
{
size_t i;
for (i = 0; i < sizeof trie->table / sizeof(struct pic_trie *); ++i) {
if (trie->table[i] != NULL) {
pic_trie_delete(pic, trie->table[i]);
}
}
pic_free(pic, trie);
}
void
pic_define_reader(pic_state *pic, const char *str, pic_func_t reader)
{
struct pic_trie *trie = pic->reader->trie;
int c;
while ((c = *str++)) {
if (trie->table[c] == NULL) {
trie->table[c] = pic_trie_new(pic);
}
trie = trie->table[c];
}
trie->proc = pic_proc_new(pic, reader, "reader");
}
#define DEFINE_READER(name) \
static pic_value \
pic_##name(pic_state *pic) \
{ \
struct pic_port *port; \
const char *str; \
\
pic_get_args(pic, "pz", &port, &str); \
\
return name(pic, port, str); \
}
DEFINE_READER(read_unmatch)
DEFINE_READER(read_comment)
DEFINE_READER(read_quote)
DEFINE_READER(read_quasiquote)
DEFINE_READER(read_unquote)
DEFINE_READER(read_unquote_splicing)
DEFINE_READER(read_string)
DEFINE_READER(read_pipe)
DEFINE_READER(read_plus)
DEFINE_READER(read_minus)
DEFINE_READER(read_pair)
DEFINE_READER(read_directive)
DEFINE_READER(read_block_comment)
DEFINE_READER(read_datum_comment)
DEFINE_READER(read_true)
DEFINE_READER(read_false)
DEFINE_READER(read_char)
DEFINE_READER(read_vector)
DEFINE_READER(read_blob)
DEFINE_READER(read_eval)
DEFINE_READER(read_symbol)
DEFINE_READER(read_number)
DEFINE_READER(read_label)
void
pic_init_reader(pic_state *pic)
{
static const char INIT[] = "!$%&*./:<=>?@^_~";
char buf[3] = { 0 };
size_t i;
pic_define_reader(pic, ")", pic_read_unmatch);
pic_define_reader(pic, ";", pic_read_comment);
pic_define_reader(pic, "'", pic_read_quote);
pic_define_reader(pic, "`", pic_read_quasiquote);
pic_define_reader(pic, ",", pic_read_unquote);
pic_define_reader(pic, ",@", pic_read_unquote_splicing);
pic_define_reader(pic, "\"", pic_read_string);
pic_define_reader(pic, "|", pic_read_pipe);
pic_define_reader(pic, "+", pic_read_plus);
pic_define_reader(pic, "-", pic_read_minus);
pic_define_reader(pic, "(", pic_read_pair);
pic_define_reader(pic, "[", pic_read_pair);
pic_define_reader(pic, "#!", pic_read_directive);
pic_define_reader(pic, "#|", pic_read_block_comment);
pic_define_reader(pic, "#;", pic_read_datum_comment);
pic_define_reader(pic, "#t", pic_read_true);
pic_define_reader(pic, "#true", pic_read_true);
pic_define_reader(pic, "#f", pic_read_false);
pic_define_reader(pic, "#false", pic_read_false);
pic_define_reader(pic, "#\\", pic_read_char);
pic_define_reader(pic, "#(", pic_read_vector);
pic_define_reader(pic, "#u", pic_read_blob);
pic_define_reader(pic, "#.", pic_read_eval);
/* read number */
for (buf[0] = '0'; buf[0] <= '9'; ++buf[0]) {
pic_define_reader(pic, buf, pic_read_number);
}
/* read symbol */
for (buf[0] = 'a'; buf[0] <= 'z'; ++buf[0]) {
pic_define_reader(pic, buf, pic_read_symbol);
}
for (buf[0] = 'A'; buf[0] <= 'Z'; ++buf[0]) {
pic_define_reader(pic, buf, pic_read_symbol);
}
for (i = 0; i < sizeof INIT; ++i) {
buf[0] = INIT[i];
pic_define_reader(pic, buf, pic_read_symbol);
}
/* read label */
buf[0] = '#';
for (buf[1] = '0'; buf[1] <= '9'; ++buf[1]) {
pic_define_reader(pic, buf, pic_read_label);
}
}
pic_value
pic_read(pic_state *pic, struct pic_port *port)
{
pic_value val;
int c = next(port);
retry:
c = skip(port, c);
if (c == EOF) {
return pic_eof_object();
}
val = read_nullable(pic, port, c);
if (pic_undef_p(val)) {
c = next(port);
goto retry;
}
return val;
}
pic_value
pic_read_cstr(pic_state *pic, const char *str)
{
struct pic_port *port;
port = pic_open_input_string(pic, str);
return pic_read(pic, port);
}
static pic_value
pic_read_read(pic_state *pic)
{
struct pic_port *port = pic_stdin(pic);
pic_get_args(pic, "|p", &port);
return pic_read(pic, port);
}
void
pic_init_read(pic_state *pic)
{
2014-08-31 22:37:52 -04:00
pic_defun(pic, "read", pic_read_read);
2014-08-25 00:38:09 -04:00
}