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chibi-scheme/sexp.c
Alex Shinn 105c317700 initial import
2009-02-18 03:14:31 +09:00

1457 lines
37 KiB
C
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
/* simple tagging
* ends in 00: pointer
* 01: fixnum
* 011: symbol
* 111: immediate symbol
* 0110: char
* 1110: other immediate object (NULL, TRUE, FALSE)
*/
#define SEXP_FIXNUM_BITS 2
#define SEXP_IMMEDIATE_BITS 3
#define SEXP_EXTENDED_BITS 4
#define SEXP_FIXNUM_MASK 3
#define SEXP_IMMEDIATE_MASK 7
#define SEXP_EXTENDED_MASK 15
#define SEXP_POINTER_TAG 0
#define SEXP_FIXNUM_TAG 1
#define SEXP_LSYMBOL_TAG 3
#define SEXP_ISYMBOL_TAG 7
#define SEXP_CHAR_TAG 6
enum sexp_types {
SEXP_FIXNUM,
SEXP_CHAR,
SEXP_BOOLEAN,
SEXP_PAIR,
SEXP_SYMBOL,
SEXP_STRING,
SEXP_VECTOR,
SEXP_PROCEDURE,
SEXP_ENV,
SEXP_BYTECODE,
SEXP_CORE,
SEXP_OPCODE,
};
typedef struct sexp_struct {
char tag;
void *data1;
void *data2;
} *sexp;
#include "sexp-hufftabs.c"
static int initialized_p = 0;
/* static sexp the_dot_symbol; */
static sexp the_quote_symbol;
static sexp the_quasiquote_symbol;
static sexp the_unquote_symbol;
static sexp the_unquote_splicing_symbol;
static sexp the_lambda_symbol;
static sexp the_begin_symbol;
static sexp the_define_symbol;
static sexp the_set_x_symbol;
static sexp the_if_symbol;
#define MAKE_IMMEDIATE(n) ((sexp) ((n<<4) + 14))
#define SEXP_NULL MAKE_IMMEDIATE(0)
#define SEXP_FALSE MAKE_IMMEDIATE(1)
#define SEXP_TRUE MAKE_IMMEDIATE(2)
#define SEXP_EOF MAKE_IMMEDIATE(3)
#define SEXP_UNDEF MAKE_IMMEDIATE(4)
#define SEXP_ERROR MAKE_IMMEDIATE(5)
#define SEXP_CLOSE MAKE_IMMEDIATE(6) /* internal use */
#define SEXP_RAWDOT MAKE_IMMEDIATE(7) /* internal use */
#define SEXP_NULLP(x) ((x) == SEXP_NULL)
#define SEXP_POINTERP(x) (((unsigned long)(x) & SEXP_FIXNUM_MASK) == SEXP_POINTER_TAG)
#define SEXP_INTEGERP(x) (((unsigned long)(x) & SEXP_FIXNUM_MASK) == SEXP_FIXNUM_TAG)
#define SEXP_ISYMBOLP(x) (((unsigned long)(x) & SEXP_IMMEDIATE_MASK) == SEXP_ISYMBOL_TAG)
#define SEXP_CHARP(x) (((unsigned long)(x) & SEXP_EXTENDED_MASK) == SEXP_CHAR_TAG)
#define SEXP_BOOLEANP(x) (((x) == SEXP_TRUE) || ((x) == SEXP_FALSE))
#define SEXP_PAIRP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_PAIR)
#define SEXP_STRINGP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_STRING)
#define SEXP_LSYMBOLP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_SYMBOL)
#define SEXP_VECTORP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_VECTOR)
#define SEXP_PROCEDUREP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_PROCEDURE)
#define SEXP_ENVP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_ENV)
#define SEXP_BYTECODEP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag ==SEXP_BYTECODE)
#define SEXP_COREP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_CORE)
#define SEXP_OPCODEP(x) (SEXP_POINTERP(x) && ((sexp)(x))->tag == SEXP_OPCODE)
#define SEXP_SYMBOLP(x) (SEXP_ISYMBOLP(x) || SEXP_LSYMBOLP(x))
/* #define SEXP_DOTP(x) (SEXP_SYMBOLP(x) && (strncmp(string_data(x), ".", 2) == 0)) */
/* #define SEXP_DOTP(x) (x==the_dot_symbol) */
#define SEXP_DOTP(x) (((unsigned long)(x))==((0x5D00<<SEXP_IMMEDIATE_BITS)+SEXP_ISYMBOL_TAG))
#define SEXP_ALLOC(size) (malloc(size))
#define SEXP_FREE free
#define SEXP_NEW() ((sexp) SEXP_ALLOC(sizeof(struct sexp_struct)))
#define make_integer(n) ((sexp) (((long) n<<SEXP_FIXNUM_BITS) + SEXP_FIXNUM_TAG))
#define unbox_integer(n) ((long) n>>SEXP_FIXNUM_BITS)
#define make_character(n) ((sexp) (((long) n<<SEXP_EXTENDED_BITS) + SEXP_CHAR_TAG))
#define unbox_character(n) ((long) n>>SEXP_EXTENDED_BITS)
#define vector_length(x) ((unsigned long) x->data1)
#define vector_data(x) ((sexp*) x->data2)
#define procedure_code(x) ((bytecode) ((sexp)x)->data1)
#define procedure_vars(x) ((sexp) ((sexp)x)->data2)
#define string_length(x) ((unsigned long) x->data1)
#define string_data(x) ((char*) x->data2)
#define symbol_pointer(x) ((sexp) (((unsigned long)x)-SEXP_LSYMBOL_TAG))
#define symbol_length(x) ((unsigned long) (symbol_pointer(x)->data1))
#define symbol_data(x) ((char*) (symbol_pointer(x)->data2))
#define sexp_add(a, b) ((sexp)(((unsigned long)a)+((unsigned long)b)-SEXP_FIXNUM_TAG))
#define sexp_sub(a, b) ((sexp)(((unsigned long)a)-((unsigned long)b)+SEXP_FIXNUM_TAG))
#define sexp_mul(a, b) ((sexp)((((((unsigned long)a)-SEXP_FIXNUM_TAG)*(((unsigned long)b)>>SEXP_FIXNUM_BITS))+SEXP_FIXNUM_TAG)))
#define sexp_div(a, b) ((sexp)(((((unsigned long)a)>>SEXP_FIXNUM_BITS)/(((unsigned long)b)>>SEXP_FIXNUM_BITS))<<SEXP_FIXNUM_BITS)+SEXP_FIXNUM_TAG)
#define sexp_mod(a, b) ((sexp)(((((unsigned long)a)>>SEXP_FIXNUM_BITS)%(((unsigned long)b)>>SEXP_FIXNUM_BITS))<<SEXP_FIXNUM_BITS)+SEXP_FIXNUM_TAG)
sexp cons(sexp head, sexp tail) {
sexp pair = SEXP_NEW();
if (! pair) return SEXP_ERROR;
pair->tag = SEXP_PAIR;
pair->data1 = (void*) head;
pair->data2 = (void*) tail;
return pair;
}
#define list2(a, b) cons(a, cons(b, SEXP_NULL))
#define list3(a, b, c) cons(a, cons(b, cons(c, SEXP_NULL)))
#define list4(a, b, c, d) cons(a, cons(b, cons(c, cons(d, SEXP_NULL))))
#define SEXP_CAR(x) (((sexp)x)->data1)
#define SEXP_CDR(x) (((sexp)x)->data2)
#define SEXP_CAAR(x) (SEXP_CAR(SEXP_CAR(x)))
#define SEXP_CADR(x) (SEXP_CAR(SEXP_CDR(x)))
#define SEXP_CDAR(x) (SEXP_CDR(SEXP_CAR(x)))
#define SEXP_CDDR(x) (SEXP_CDR(SEXP_CDR(x)))
#define SEXP_CADDR(x) (SEXP_CAR(SEXP_CDDR(x)))
#define SEXP_CDDDR(x) (SEXP_CDR(SEXP_CDDR(x)))
#define SEXP_CADDDR(x) (SEXP_CADR(SEXP_CDDR(x)))
#define SEXP_CDDDDR(x) (SEXP_CDDR(SEXP_CDDR(x)))
sexp read_sexp (FILE *in);
/* separators: space, tab, newline, ; () [] , ' " */
/* 9 10 11 12 13 32 34 39 40 41 44 59 91 93 */
/* 0 1 2 3 4 23 25 30 31 32 35 50 82 84 */
/* 0000000 */
/* 0000001 */
/* 0000010 */
/* 0000011 */
/* 0000100 */
/* 0010111 */
/* 0011001 */
/* 0011110 */
/* 0011111 */
/* 0100000 */
/* 0100011 */
/* 0110010 */
/* 1010010 */
/* 1010100 */
static char separators[] = {
/* 1 2 3 4 5 6 7 8 9 a b c d e f */
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, /* x0_ */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* x1_ */
1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, /* x2_ */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, /* x3_ */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* x4_ */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, /* x5_ */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* x6_ */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* x7_ */
};
static int is_separator (int c) {
/* return (!((c-9)&(~3))) | (~(c^4)); */
return 0<c && c<128 && separators[c];
}
sexp car(sexp obj) {
return (SEXP_PAIRP(obj)) ? SEXP_CAR(obj) : SEXP_ERROR;
}
sexp cdr(sexp obj) {
return (SEXP_PAIRP(obj)) ? SEXP_CDR(obj) : SEXP_ERROR;
}
sexp set_car(sexp obj, sexp val) {
if (SEXP_PAIRP(obj)) {
return SEXP_CAR(obj) = val;
} else {
return SEXP_ERROR;
}
}
int listp (sexp obj) {
while (SEXP_PAIRP(obj))
obj = SEXP_CDR(obj);
return (obj == SEXP_NULL);
}
int list_index (sexp ls, sexp elt) {
int i=0;
while (SEXP_PAIRP(ls)) {
if (SEXP_CAR(ls) == elt)
return i;
ls = SEXP_CDR(ls);
i++;
}
return -1;
}
sexp set_cdr(sexp obj, sexp val) {
if (SEXP_PAIRP(obj)) {
return SEXP_CDR(obj) = val;
} else {
return SEXP_ERROR;
}
}
sexp reverse(sexp ls) {
sexp res = SEXP_NULL;
for ( ; SEXP_PAIRP(ls); ls=SEXP_CDR(ls))
res = cons(SEXP_CAR(ls), res);
return res;
}
sexp nreverse(sexp ls) {
sexp a;
sexp b;
sexp tmp;
if (ls == SEXP_NULL) {
return ls;
} else if (! SEXP_PAIRP(ls)) {
return SEXP_ERROR;
} else {
b = ls;
a=cdr(ls);
set_cdr(b, SEXP_NULL);
for ( ; SEXP_PAIRP(a); ) {
tmp = cdr(a);
set_cdr(a, b);
b = a;
a = tmp;
}
return b;
}
}
sexp list(int count, ...) {
sexp res = SEXP_NULL;
int i;
va_list ap;
va_start(ap, count);
for (i=0; i<count; i++) {
res = cons(va_arg(ap, sexp), res);
}
va_end(ap);
return nreverse(res);
}
unsigned long length(sexp ls) {
sexp x;
unsigned long res;
for (res=0, x=ls; SEXP_PAIRP(x); res++, x=cdr(x))
;
return res;
}
sexp make_string(char *str) {
sexp s = SEXP_NEW();
if (! s) return SEXP_ERROR;
unsigned long len = strlen(str);
char *mystr = SEXP_ALLOC(len+1);
if (! mystr) { SEXP_FREE(s); return SEXP_ERROR; }
memcpy(mystr, str, len+1);
s->tag = SEXP_STRING;
s->data1 = (void*) len;
s->data2 = (void*) mystr;
return s;
}
struct huff_entry {
unsigned char len;
unsigned short bits;
};
static struct huff_entry huff_table[] = {
#include "sexp-huff.c"
};
/* http://planetmath.org/encyclopedia/GoodHashTablePrimes.html */
static sexp* symbol_table = NULL;
static unsigned long symbol_table_primes[] = {
97, 389, 1543, 6151, 12289, 24593, 49157, 98317, 196613, 393241,
786433, 1572869, 3145739, 6291469, 12582917, 25165843, 50331653,
100663319, 201326611, 402653189, 805306457, 1610612741};
static int symbol_table_prime_index = 0;
static int symbol_table_count = 0;
#define FNV_PRIME 16777619
#define FNV_OFFSET_BASIS 2166136261uL
int string_hash(char *str, int acc) {
while (*str) {acc *= FNV_PRIME; acc ^= *str++;}
return acc;
}
sexp intern(char *str) {
struct huff_entry he;
unsigned long len, res=FNV_OFFSET_BASIS, space=3, newbits, i, d, cell;
char c, *mystr, *p=str;
sexp sym, *newtable;
res = 0;
for (p=str; c=*p; p++) {
he = huff_table[c];
newbits = he.len;
if ((space+newbits) > (sizeof(sexp)*8)) {
goto normal_intern;
}
res |= (((unsigned long) he.bits) << space);
space += newbits;
}
/* fprintf(stderr, "immediate symbol: %x\n", res); */
return (sexp) (res + SEXP_ISYMBOL_TAG);
normal_intern:
/* fprintf(stderr, "normal intern\n"); */
res = string_hash(p, res);
d = symbol_table_primes[symbol_table_prime_index];
cell = res % d;
for (i=0; i<d; i++) {
if (! symbol_table[cell]) {
break;
} else if (strncmp(str,
symbol_data(symbol_table[cell]),
symbol_length(symbol_table[cell])) == 0) {
return symbol_table[cell];
}
cell = (cell * res + 1) % d;
}
symbol_table_count++;
resize:
if (symbol_table_count*5 > d*4) {
fprintf(stderr, "resizing symbol table\n");
newtable = malloc(symbol_table_primes[symbol_table_prime_index++]
* sizeof(sexp));
free(symbol_table);
symbol_table = newtable;
}
new_entry:
sym = SEXP_NEW();
if (! sym) return SEXP_ERROR;
len = strlen(str);
mystr = SEXP_ALLOC(len+1);
if (! mystr) { SEXP_FREE(sym); return SEXP_ERROR; }
memcpy(mystr, str, len+1);
sym->tag = SEXP_SYMBOL;
sym->data1 = (void*) len;
sym->data2 = (void*) mystr;
symbol_table[cell] = (sexp) (((unsigned long)sym) + 3);
return symbol_table[cell];
}
sexp make_vector(unsigned long len, sexp dflt) {
int i;
sexp v = SEXP_NEW();
if (v == NULL) return SEXP_ERROR;
sexp *x = (void*) SEXP_ALLOC(len*sizeof(sexp));
if (x == NULL) return SEXP_ERROR;
for (i=0; i<len; i++) {
x[i] = dflt;
}
v->tag = SEXP_VECTOR;
v->data1 = (void*) len;
v->data2 = (void*) x;
return v;
}
sexp list_to_vector(sexp ls) {
sexp vec = make_vector(length(ls), SEXP_FALSE);
if (vec == SEXP_ERROR) return vec;
sexp x;
sexp *elts = vector_data(vec);
int i;
for (i=0, x=ls; SEXP_PAIRP(x); i++, x=cdr(x)) {
elts[i] = car(x);
}
return vec;
}
sexp vector(int count, ...) {
sexp vec = make_vector(count, SEXP_FALSE);
if (vec == SEXP_ERROR) return vec;
sexp *elts = vector_data(vec);
va_list ap;
int i;
va_start(ap, count);
for (i=0; i<count; i++) {
elts[i] = va_arg(ap, sexp);
}
va_end(ap);
return vec;
}
void write_sexp (FILE *out, sexp obj) {
unsigned long len, i, c, res;
sexp x;
if (! obj) {
fprintf(out, "#<null>");
} else if (SEXP_POINTERP(obj)) {
switch (obj->tag) {
case SEXP_PAIR:
fprintf(out, "(");
write_sexp(out, car(obj));
for (x=cdr(obj); SEXP_PAIRP(x); x=cdr(x)) {
fprintf(out, " ");
write_sexp(out, car(x));
}
if (! SEXP_NULLP(x)) {
fprintf(out, " . ");
write_sexp(out, x);
}
fprintf(out, ")");
break;
case SEXP_VECTOR:
len = vector_length(obj);
sexp *elts = vector_data(obj);
if (len == 0) {
fprintf(out, "#()");
} else {
fprintf(out, "#(");
write_sexp(out, elts[0]);
for (i=1; i<len; i++) {
fprintf(out, " ");
write_sexp(out, elts[i]);
}
fprintf(out, ")");
}
break;
case SEXP_PROCEDURE:
fprintf(out, "#<procedure>");
break;
case SEXP_STRING:
fprintf(out, "\"");
/* FALLTHROUGH */
case SEXP_SYMBOL:
fprintf(out, "%s", string_data(obj));
if (obj->tag == SEXP_STRING) {
fprintf(out, "\"");
}
break;
}
} else if (SEXP_INTEGERP(obj)) {
fprintf(out, "%d", unbox_integer(obj));
} else if (SEXP_CHARP(obj)) {
if (33 <= unbox_character(obj) < 127) {
fprintf(out, "#\\%c", unbox_character(obj));
} else {
fprintf(out, "#\\x%02d", unbox_character(obj));
}
} else if (SEXP_SYMBOLP(obj)) {
if (((unsigned long)obj&7)==7) {
c = ((unsigned long)obj)>>3;
while (c) {
#include "sexp-unhuff.c"
putc(res, out);
}
} else {
fprintf(out, "%s", symbol_data(obj));
}
} else {
switch ((unsigned long) obj) {
case (int) SEXP_NULL:
fprintf(out, "()");
break;
case (int) SEXP_TRUE:
fprintf(out, "#t");
break;
case (int) SEXP_FALSE:
fprintf(out, "#f");
break;
case (int) SEXP_EOF:
fprintf(out, "#<eof>");
break;
case (int) SEXP_UNDEF:
fprintf(out, "#<undef>");
break;
default:
fprintf(out, "#<error>");
}
}
}
void* free_sexp (sexp obj) {
int len, i;
sexp *elts;
if (SEXP_POINTERP(obj)) {
switch (obj->tag) {
case SEXP_PAIR:
free_sexp(car(obj));
free_sexp(cdr(obj));
break;
case SEXP_VECTOR:
len = vector_length(obj);
elts = vector_data(obj);
for (i=0; i<len; i++) {
free_sexp(elts[i]);
}
SEXP_FREE(elts);
break;
case SEXP_STRING:
case SEXP_SYMBOL:
free(string_data(obj));
break;
}
SEXP_FREE(obj);
}
}
char* read_string(FILE *in) {
char *buf, *tmp, *res;
char c;
int len;
buf = SEXP_ALLOC(128);
tmp = buf;
for (c=fgetc(in); (c != EOF) && (c != '"'); c=fgetc(in)) {
if (c == '\\') {
c=fgetc(in);
switch (c) {
case 'n':
c = '\n';
case 't':
c = '\t';
}
*tmp++ = c;
} else {
*tmp++ = c;
}
}
*tmp++ = '\0';
len = tmp - buf;
res = SEXP_ALLOC(len);
memcpy(res, buf, len);
SEXP_FREE(buf);
return res;
}
char* read_symbol(FILE *in, int init) {
char *buf, *tmp, *res;
char c;
int len;
buf = SEXP_ALLOC(128);
tmp = buf;
if (init != EOF)
*tmp++ = init;
while (1) {
c=fgetc(in);
if (c == EOF || is_separator(c)) {
ungetc(c, in);
break;
}
*tmp++ = c;
}
*tmp++ = '\0';
len = tmp - buf;
res = SEXP_ALLOC(len);
memcpy(res, buf, len);
SEXP_FREE(buf);
return res;
}
int read_number(FILE *in) {
int res = 0;
int negativep = 0;
char c;
c = fgetc(in);
if (c == '-') {
negativep = 1;
} else if (isdigit(c)) {
res = c - '0';
}
for (c=fgetc(in); isdigit(c); c=fgetc(in)) {
res = res * 10 + (c - '0');
}
ungetc(c, in);
return negativep ? -res : res;
}
sexp read_sexp_raw (FILE *in) {
sexp res, tmp, tmp2;
char *str;
int c1, c2;
scan_loop:
switch (c1 = fgetc(in)) {
case EOF:
res = SEXP_EOF;
break;
case ';':
while ((c1 = fgetc(in)) != EOF)
if (c1 == '\n')
break;
/* fallthrough */
case ' ':
case '\t':
case '\n':
goto scan_loop;
break;
case '\'':
res = read_sexp(in);
res = list2(the_quote_symbol, res);
break;
case '`':
res = read_sexp(in);
res = list2(the_quasiquote_symbol, res);
break;
case ',':
if ((c1 = fgetc(in)) == '@') {
res = read_sexp(in);
res = list2(the_unquote_splicing_symbol, res);
} else {
ungetc(c1, in);
res = read_sexp(in);
res = list2(the_unquote_symbol, res);
}
break;
case '"':
str = read_string(in);
res = make_string(str);
free(str);
break;
case '(':
res = SEXP_NULL;
tmp = read_sexp_raw(in);
while ((tmp != SEXP_ERROR) && (tmp != SEXP_EOF) && (tmp != SEXP_CLOSE)) {
if (tmp == SEXP_RAWDOT) {
/* dotted list */
free_sexp(tmp);
tmp = read_sexp_raw(in);
if (read_sexp(in) != SEXP_CLOSE) {
fprintf(stderr, "sexp: multiple tokens in dotted tail\n");
res = SEXP_ERROR;
} else {
tmp2 = res;
res = nreverse(res);
set_cdr(tmp2, tmp);
return res;
}
} else {
res = cons(tmp, res);
tmp = read_sexp_raw(in);
}
}
if (tmp != SEXP_CLOSE) {
free_sexp(res);
res = SEXP_ERROR;
}
res = nreverse(res);
break;
case '#':
switch (c1=fgetc(in)) {
/* case 'b': */
/* case 'd': */
/* case 'o': */
/* case 'x': */
/* case 'e': */
/* case 'i': */
case 'f':
case 't':
c2 = fgetc(in);
if (c2 == EOF || is_separator(c2)) {
res = (c1 == 't' ? SEXP_TRUE : SEXP_FALSE);
} else {
fprintf(stderr, "sexp: invalid syntax #%c%c\n", c1, c2);
res = SEXP_ERROR;
}
ungetc(c2, in);
break;
case '(':
ungetc(c1, in);
res = read_sexp(in);
if (! listp(res)) {
if (res != SEXP_ERROR) {
fprintf(stderr, "sexp: dotted list not allowed in vector syntax\n");
free_sexp(res);
res = SEXP_ERROR;
}
} else {
res = list_to_vector(res);
}
break;
default:
fprintf(stderr, "sexp: invalid syntax #%c\n", c1);
res = SEXP_ERROR;
break;
}
break;
case '.':
c1 = fgetc(in);
if (c1 == EOF || is_separator(c1)) {
res = SEXP_RAWDOT;
} else if (isdigit(c1)) {
ungetc(c1,in );
/* res = read_float_tail(in); */
res = SEXP_ERROR;
} else {
ungetc(c1, in);
str = read_symbol(in, '.');
res = intern(str);
free(str);
}
break;
case ')':
res = SEXP_CLOSE;
break;
case '+':
case '-':
fprintf(stderr, "plus/minus: %c\n", c1);
c2 = fgetc(in);
if (c2 == '.' || isdigit(c2)) {
ungetc(c2, in);
res = make_integer(read_number(in) * ((c1 == '-') ? -1 : 1));
} else {
fprintf(stderr, "... symbol: %c\n", c2);
ungetc(c2, in);
str = read_symbol(in, c1);
res = intern(str);
free(str);
}
break;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
ungetc(c1, in);
res = make_integer(read_number(in));
break;
default:
str = read_symbol(in, c1);
res = intern(str);
free(str);
break;
}
return res;
}
sexp read_sexp (FILE *in) {
sexp res = read_sexp_raw(in);
if ((res == SEXP_CLOSE) || (res == SEXP_RAWDOT)) {
res = SEXP_ERROR;
}
}
void sexp_init() {
if (! initialized_p) {
initialized_p = 1;
symbol_table = malloc(symbol_table_primes[0]*sizeof(sexp));
/* the_dot_symbol = intern("."); */
the_quote_symbol = intern("quote");
the_quasiquote_symbol = intern("quasiquote");
the_unquote_symbol = intern("unquote");
the_unquote_splicing_symbol = intern("unquote-splicing");
the_lambda_symbol = intern("lambda");
the_begin_symbol = intern("begin");
the_define_symbol = intern("define");
the_set_x_symbol = intern("set!");
the_if_symbol = intern("if");
}
}
/* ******************************************************************** */
#ifdef HAVE_ERR_H
#include <err.h>
#else
#define errx(code, msg, ...) (fprintf(stderr,msg"\n",__VA_ARGS__), exit(code))
#endif
#define INIT_BCODE_SIZE 128
#define INIT_STACK_SIZE 1024
typedef struct bytecode {
char tag;
unsigned int len;
unsigned char data[];
} *bytecode;
/* env binding: #(id chain offset flags) */
/* chain is the index into the closure parent list (0 for current lambda) */
/* macros/constants have a value instead of chain */
typedef struct env {
char tag;
struct env *parent;
sexp bindings;
} *env;
enum core_form_names {
CORE_DEFINE,
CORE_SET,
CORE_LAMBDA,
CORE_IF,
CORE_BEGIN,
CORE_QUOTE,
CORE_DEFINE_SYNTAX,
CORE_LET_SYNTAX,
CORE_LETREC_SYNTAX,
};
typedef struct core_form {
char tag;
char* name;
char code;
} *core_form;
static struct core_form core_forms[] = {
{SEXP_CORE, "define", CORE_DEFINE},
{SEXP_CORE, "set!", CORE_SET},
{SEXP_CORE, "lambda", CORE_LAMBDA},
{SEXP_CORE, "if", CORE_IF},
{SEXP_CORE, "begin", CORE_BEGIN},
{SEXP_CORE, "quote", CORE_QUOTE},
{SEXP_CORE, "define-syntax", CORE_DEFINE_SYNTAX},
{SEXP_CORE, "let-syntax", CORE_LET_SYNTAX},
{SEXP_CORE, "letrec-syntax", CORE_LETREC_SYNTAX},
};
enum opcode_classes {
OPC_GENERIC,
OPC_TYPE_PREDICATE,
OPC_PREDICATE,
OPC_ARITHMETIC,
OPC_ARITHMETIC_INV,
OPC_ARITHMETIC_CMP,
OPC_CONSTRUCTOR,
};
/* #define OP_UNSAFE(op) ((op)+128) */
enum opcode_names {
OP_NOOP,
OP_STACK_REF,
OP_STACK_SET,
OP_GLOBAL_REF,
OP_GLOBAL_SET,
OP_CLOSURE_REF,
OP_CLOSURE_SET,
OP_PUSH,
OP_DUP,
OP_DROP,
OP_SWAP,
OP_CAR,
OP_CDR,
OP_CONS,
OP_ADD,
OP_SUB,
OP_MUL,
OP_DIV,
OP_MOD,
OP_NEG,
OP_INV,
OP_LT,
OP_CALL,
OP_JUMP_UNLESS,
OP_JUMP,
OP_RET,
OP_DONE,
};
typedef struct opcode {
char tag;
char op_class;
char op_name;
char num_args;
char var_args_p;
char arg1_type;
char arg2_type;
char* name;
sexp proc;
} *opcode;
static struct opcode opcodes[] = {
{SEXP_OPCODE, OPC_TYPE_PREDICATE, OP_CAR, 1, 0, SEXP_PAIR, 0, "car", NULL},
{SEXP_OPCODE, OPC_TYPE_PREDICATE, OP_CDR, 1, 0, SEXP_PAIR, 0, "cdr", NULL},
{SEXP_OPCODE, OPC_ARITHMETIC, OP_ADD, 0, 1, SEXP_FIXNUM, 0, "+", NULL},
{SEXP_OPCODE, OPC_ARITHMETIC_INV, OP_SUB, 0, 1, SEXP_FIXNUM, 0, "-", NULL},
{SEXP_OPCODE, OPC_ARITHMETIC, OP_MUL, 0, 1, SEXP_FIXNUM, 0, "*", NULL},
{SEXP_OPCODE, OPC_ARITHMETIC_INV, OP_DIV, 0, 1, SEXP_FIXNUM, 0, "/", NULL},
{SEXP_OPCODE, OPC_ARITHMETIC, OP_MOD, 2, 0, SEXP_FIXNUM, SEXP_FIXNUM, "%", NULL},
{SEXP_OPCODE, OPC_ARITHMETIC_CMP, OP_LT, 0, 1, SEXP_FIXNUM, 0, "<", NULL},
};
sexp env_cell(env e, sexp key) {
sexp ls, res=NULL;
do {
for (ls=e->bindings; SEXP_PAIRP(ls); ls=SEXP_CDR(ls)) {
if (SEXP_CAAR(ls) == key) {
res = SEXP_CAR(ls);
break;
}
}
e = e->parent;
} while (e && ! res);
return res;
}
sexp make_procedure(sexp bc, sexp vars) {
sexp proc = SEXP_NEW();
if (! proc) return SEXP_ERROR;
proc->tag = SEXP_PROCEDURE;
proc->data1 = (void*) bc;
proc->data2 = (void*) vars;
return proc;
}
void env_define(env e, sexp key, sexp value) {
sexp cell = env_cell(e, key);
if (cell) {
SEXP_CDR(cell) = value;
} else {
e->bindings = cons(cons(key, value), e->bindings);
}
}
env make_standard_env() {
int i;
env e = (env) malloc(sizeof(struct env));
e->tag = SEXP_ENV;
e->parent = NULL;
e->bindings = SEXP_NULL;
for (i=0; i<(sizeof(core_forms)/sizeof(struct core_form)); i++) {
env_define(e, intern(core_forms[i].name), (sexp)(&core_forms[i]));
}
for (i=0; i<(sizeof(opcodes)/sizeof(struct opcode)); i++) {
env_define(e, intern(opcodes[i].name), (sexp)(&opcodes[i]));
}
return e;
}
/* ******************************************************************** */
/* char *buffncpy(char *buf, unsigned int n, unsigned int len) { */
/* char *res; */
/* if (n==len) { */
/* res = buf; */
/* } else { */
/* res = (char*) malloc(n); */
/* strncpy(res, buf, n); */
/* free(buf); */
/* } */
/* return res; */
/* } */
/* char *buffngrow(char *buf, unsigned int newlen) { */
/* char *tmp = (char*) malloc(newlen); */
/* strncpy(tmp, buf, newlen/2); */
/* free(buf); */
/* return tmp; */
/* } */
void print_bytecode (bytecode bc) {
int i;
fprintf(stderr, "bytecode @ %p, data @ %p, length = %d\n", bc, bc->data, bc->len);
for (i=0; i+8 < bc->len; i+=8) {
fprintf(stderr, "%02x: %02x %02x %02x %02x %02x %02x %02x %02x\n", i,
bc->data[i], bc->data[i+1], bc->data[i+2], bc->data[i+3],
bc->data[i+4], bc->data[i+5], bc->data[i+6], bc->data[i+7]);
}
if (i != bc->len) {
fprintf(stderr, "%02x:", i);
for ( ; i < bc->len; i++) {
fprintf(stderr, " %02x", bc->data[i]);
}
fprintf(stderr, "\n");
}
}
void print_stack (sexp *stack, int top) {
int i;
for (i=0; i<top; i++) {
fprintf(stderr, " %02d: ", i);
fflush(stderr);
write_sexp(stderr, stack[i]);
fprintf(stderr, "\n");
}
}
void shrink_bcode(bytecode *bc, unsigned int i) {
bytecode tmp;
if ((*bc)->len != i) {
fprintf(stderr, "shrinking to %d\n", i);
tmp = (bytecode) malloc(sizeof(struct bytecode) + i);
tmp->tag = SEXP_BYTECODE;
tmp->len = i;
memcpy(tmp->data, (*bc)->data, i);
SEXP_FREE(*bc);
*bc = tmp;
}
}
void emit(bytecode *bc, unsigned int *i, char c) {
bytecode tmp;
if ((*bc)->len < (*i)+1) {
fprintf(stderr, "expanding (%d < %d)\n", (*bc)->len, (*i)+1);
tmp = (bytecode) malloc(sizeof(unsigned int) + (*bc)->len*2);
tmp->len = (*bc)->len*2;
memcpy(tmp->data, (*bc)->data, (*bc)->len);
SEXP_FREE(*bc);
*bc = tmp;
}
(*bc)->data[(*i)++] = c;
}
void emit_word(bytecode *bc, unsigned int *i, unsigned long val) {
bytecode tmp;
if ((*bc)->len < (*i)+4) {
tmp = (bytecode) malloc(sizeof(unsigned int) + (*bc)->len*2);
tmp->len = (*bc)->len*2;
memcpy(tmp->data, (*bc)->data, (*bc)->len);
SEXP_FREE(*bc);
*bc = tmp;
}
*((unsigned long*)(&((*bc)->data[*i]))) = val;
*i += sizeof(unsigned long);
}
bytecode compile(sexp params, sexp obj, env e, int done_p);
void analyze_app (sexp obj, bytecode *bc, unsigned int *i,
env e, sexp params, unsigned int *d);
void analyze_lambda (sexp name, sexp formals, sexp body,
bytecode *bc, unsigned int *i, env e,
sexp params, unsigned int *d);
void analyze(sexp obj, bytecode *bc, unsigned int *i, env e, sexp params, unsigned int *d) {
int tmp1, tmp2;
env e2 = e;
sexp o1, o2, cell;
if (SEXP_PAIRP(obj)) {
/* fprintf(stderr, ":: pair\n"); */
if (SEXP_SYMBOLP(SEXP_CAR(obj))) {
fprintf(stderr, ":: symbol application\n");
o1 = env_cell(e, SEXP_CAR(obj));
/* fprintf(stderr, ":: => %p\n", o1); */
if (! o1)
errx(1, "unknown operator: %s", SEXP_CAR(obj));
o1 = SEXP_CDR(o1);
/* fprintf(stderr, ":: => %p\n", o1); */
if (SEXP_COREP(o1)) {
/* core form */
fprintf(stderr, ":: core form\n");
switch (((core_form)o1)->code) {
case CORE_LAMBDA:
fprintf(stderr, ":: lambda\n");
analyze_lambda(SEXP_FALSE, SEXP_CADR(obj), SEXP_CADDR(obj),
bc, i, e, params, d);
break;
case CORE_DEFINE:
case CORE_SET:
fprintf(stderr, "compiling global set: %p\n", SEXP_CADR(obj));
if ((((core_form)o1)->code == CORE_DEFINE)
&& SEXP_PAIRP(SEXP_CADR(obj))) {
analyze_lambda(SEXP_CAR(SEXP_CADR(obj)),
SEXP_CDR(SEXP_CADR(obj)),
SEXP_CADDR(obj),
bc, i, e, params, d);
} else {
analyze(SEXP_CADDR(obj), bc, i, e, params, d);
}
emit(bc, i, OP_GLOBAL_SET);
emit_word(bc, i, (unsigned long) (SEXP_PAIRP(SEXP_CADR(obj))
? SEXP_CAR(SEXP_CADR(obj))
: SEXP_CADR(obj)));
emit(bc, i, OP_PUSH);
(*d)++;
emit_word(bc, i, (unsigned long) SEXP_UNDEF);
break;
case CORE_BEGIN:
for (o2 = SEXP_CDR(obj); SEXP_PAIRP(o2); o2 = SEXP_CDR(o2)) {
analyze(SEXP_CAR(o2), bc, i, e, params, d);
}
break;
case CORE_IF:
fprintf(stderr, "test clause: %d\n", *i);
analyze(SEXP_CADR(obj), bc, i, e, params, d);
emit(bc, i, OP_JUMP_UNLESS); /* jumps if test fails */
tmp1 = *i;
emit(bc, i, 0);
fprintf(stderr, "pass clause: %d\n", *i);
analyze(SEXP_CADDR(obj), bc, i, e, params, d);
emit(bc, i, OP_JUMP);
tmp2 = *i;
emit(bc, i, 0);
((signed char*) (*bc)->data)[tmp1] = (*i)-tmp1-1; /* patch */
fprintf(stderr, "fail clause: %d\n", *i);
if (SEXP_PAIRP(SEXP_CDDDR(obj))) {
analyze(SEXP_CADDDR(obj), bc, i, e, params, d);
} else {
emit(bc, i, OP_PUSH);
(*d)++;
emit_word(bc, i, (unsigned long) SEXP_UNDEF);
}
((signed char*) (*bc)->data)[tmp2] = (*i)-tmp2-1; /* patch */
break;
case CORE_QUOTE:
emit(bc, i, OP_PUSH);
(*d)++;
emit_word(bc, i, (unsigned long)SEXP_CADR(obj));
break;
default:
errx(1, "unknown core form: %s", ((core_form)o1)->code);
}
} else if (SEXP_OPCODEP(o1)) {
fprintf(stderr, ":: opcode\n");
/* direct opcode */
/* verify arity */
switch (((opcode)o1)->op_class) {
case OPC_TYPE_PREDICATE:
case OPC_PREDICATE:
case OPC_ARITHMETIC:
case OPC_ARITHMETIC_CMP:
/* fprintf(stderr, ":: class: %d\n", ((opcode)o1)->op_class); */
for (o2 = reverse(SEXP_CDR(obj)); SEXP_PAIRP(o2); o2 = SEXP_CDR(o2)) {
/* fprintf(stderr, ":: arg: %d\n", SEXP_CAR(o2)); */
analyze(SEXP_CAR(o2), bc, i, e, params, d);
}
fprintf(stderr, ":: name: %d\n", ((opcode)o1)->op_name);
emit(bc, i, ((opcode)o1)->op_name);
(*d) -= length(SEXP_CDDR(obj));
break;
default:
errx(1, "unknown opcode class: %d", ((opcode)o1)->op_class);
}
} else {
/* function call */
analyze_app(obj, bc, i, e, params, d);
}
} else if (SEXP_PAIRP(SEXP_CAR(obj))) {
o2 = env_cell(e, SEXP_CAAR(obj));
if (o2
&& SEXP_COREP(SEXP_CDR(o2))
&& (((core_form)SEXP_CDR(o2))->code == CORE_LAMBDA)) {
/* let */
} else {
/* computed application */
analyze_app(obj, bc, i, e, params, d);
}
} else {
errx(1, "invalid operator: %s", SEXP_CAR(obj));
}
} else if (SEXP_SYMBOLP(obj)) {
/* variable reference */
/* cell = env_cell(e, obj); */
fprintf(stderr, "symbol lookup, param length: %d\n", length(params));
if ((tmp1 = list_index(params, obj)) >= 0) {
fprintf(stderr, "compiling local ref: %p => %d (d = %d)\n", obj, tmp1, *d);
emit(bc, i, OP_STACK_REF);
emit_word(bc, i, tmp1 + *d + 3);
(*d)++;
} else {
fprintf(stderr, "compiling global ref: %p\n", obj);
emit(bc, i, OP_GLOBAL_REF);
emit_word(bc, i, (unsigned long) obj);
(*d)++;
}
} else {
fprintf(stderr, "push: %d\n", (unsigned long)obj);
emit(bc, i, OP_PUSH);
emit_word(bc, i, (unsigned long)obj);
(*d)++;
}
}
void analyze_app (sexp obj, bytecode *bc, unsigned int *i,
env e, sexp params, unsigned int *d) {
sexp o1;
unsigned long len = length(SEXP_CDR(obj));
/* push the arguments onto the stack */
for (o1 = reverse(SEXP_CDR(obj)); SEXP_PAIRP(o1); o1 = SEXP_CDR(o1)) {
analyze(SEXP_CAR(o1), bc, i, e, params, d);
}
/* push the operator onto the stack */
analyze(SEXP_CAR(obj), bc, i, e, params, d);
/* make the call */
emit(bc, i, OP_CALL);
emit_word(bc, i, (unsigned long) make_integer(len));
}
void analyze_lambda (sexp name, sexp formals, sexp body,
bytecode *bc, unsigned int *i, env e,
sexp params, unsigned int *d) {
sexp obj = (sexp) compile(formals, body, e, 0);
emit(bc, i, OP_PUSH);
(*d)++;
obj = make_procedure(obj, SEXP_NULL);
emit_word(bc, i, (unsigned long) obj);
}
sexp vm(bytecode bc, env e, sexp* stack, unsigned int top) {
unsigned char *ip=bc->data;
sexp cp, tmp;
int i;
loop:
/* fprintf(stderr, "opcode: %d, ip: %d\n", *ip, ip); */
/* print_bytecode(bc); */
switch (*ip++) {
case OP_NOOP:
fprintf(stderr, "noop\n");
break;
case OP_GLOBAL_REF:
fprintf(stderr, "global ref: ip: %p => %p: ", ip, ((sexp*)ip)[0]);
fflush(stderr);
write_sexp(stderr, ((sexp*)ip)[0]);
fprintf(stderr, "\n");
tmp = env_cell(e, ((sexp*)ip)[0]);
stack[top++]=SEXP_CDR(tmp);
ip += sizeof(sexp);
break;
case OP_GLOBAL_SET:
fprintf(stderr, "global set: %p: ", ((sexp*)ip)[0]);
fflush(stderr);
write_sexp(stderr, ((sexp*)ip)[0]);
fprintf(stderr, "\n");
env_define(e, ((sexp*)ip)[0], stack[--top]);
ip += sizeof(sexp);
break;
case OP_STACK_REF:
fprintf(stderr, "stack ref: ip=%p, %d - %d => ",
ip, top, (unsigned long) ((sexp*)ip)[0]);
fflush(stderr);
write_sexp(stderr, stack[top - (unsigned int) ((sexp*)ip)[0]]);
fprintf(stderr, "\n");
stack[top] = stack[top - (unsigned int) ((sexp*)ip)[0]];
ip += sizeof(sexp);
top++;
break;
case OP_CLOSURE_REF:
/* stack[top++]=cp[*ip++]; */
break;
case OP_CLOSURE_SET:
/* cp[*ip++]=stack[top--]; */
break;
case OP_PUSH:
/* fprintf(stderr, " (push)\n"); */
stack[top++]=((sexp*)ip)[0];
ip += sizeof(sexp);
break;
case OP_DUP:
stack[top]=stack[top-1];
top++;
break;
case OP_DROP:
top--;
break;
case OP_SWAP:
tmp = stack[top-2];
stack[top-2]=stack[top-1];
stack[top-1]=tmp;
break;
case OP_CAR:
stack[top-1]=car(stack[top-1]);
break;
case OP_CDR:
stack[top-1]=cdr(stack[top-1]);
break;
case OP_CONS:
stack[top-2]=cons(stack[top-2], stack[top-1]);
top--;
break;
case OP_ADD:
stack[top-2]=sexp_add(stack[top-2],stack[top-1]);
top--;
break;
case OP_SUB:
stack[top-2]=sexp_sub(stack[top-2],stack[top-1]);
top--;
break;
case OP_MUL:
stack[top-2]=sexp_mul(stack[top-2],stack[top-1]);
top--;
break;
case OP_DIV:
stack[top-2]=sexp_div(stack[top-2],stack[top-1]);
top--;
break;
case OP_MOD:
stack[top-2]=sexp_mod(stack[top-2],stack[top-1]);
top--;
break;
case OP_LT:
stack[top-2]=((stack[top-2] < stack[top-1]) ? SEXP_TRUE : SEXP_FALSE);
top--;
break;
case OP_CALL:
fprintf(stderr, "CALL\n");
i = (unsigned long) ((sexp*)ip)[0];
tmp = stack[top-1];
if (! SEXP_PROCEDUREP(tmp))
errx(2, "non-procedure application: %p", tmp);
stack[top-1] = (sexp) i;
stack[top] = (sexp) (ip+4);
top++;
bc = procedure_code(tmp);
print_bytecode(bc);
ip = bc->data;
fprintf(stderr, "... jumping to procedure at %p\n", ip);
/* print_stack(stack, top); */
break;
case OP_JUMP_UNLESS:
fprintf(stderr, "JUMP UNLESS, stack top is %d\n", stack[top-1]);
if (stack[--top] == SEXP_FALSE) {
fprintf(stderr, "test passed, jumping to + %d => %d\n", ((signed char*)ip)[0], ip + ((signed char*)ip)[0]);
ip += ((signed char*)ip)[0];
} else {
fprintf(stderr, "test failed, not jumping\n");
ip++;
}
break;
case OP_JUMP:
fprintf(stderr, "jumping to + %d => %d\n", ((signed char*)ip)[0], ip + ((signed char*)ip)[0]);
ip += ((signed char*)ip)[0];
break;
case OP_RET:
fprintf(stderr, "returning @ %d: ", top-1);
fflush(stderr);
write_sexp(stderr, stack[top-1]);
fprintf(stderr, "\n");
/* print_stack(stack, top); */
/* top-1 */
/* stack: args ... n ip result */
ip = (unsigned char*) stack[top-2];
i = unbox_integer(stack[top-3]);
stack[top-i-3] = stack[top-1];
top = top-i-2;
break;
case OP_DONE:
fprintf(stderr, "finally returning @ %d: ", top-1);
fflush(stderr);
write_sexp(stderr, stack[top-1]);
fprintf(stderr, "\n");
goto end_loop;
default:
fprintf(stderr, "unknown opcode: %d\n", *(ip-1));
stack[top] = SEXP_ERROR;
goto end_loop;
}
goto loop;
end_loop:
return stack[top-1];
}
bytecode compile(sexp params, sexp obj, env e, int done_p) {
bytecode bc = (bytecode) malloc(sizeof(struct bytecode)+INIT_BCODE_SIZE);
unsigned int i = 0, d = 0;
bc->tag = SEXP_BYTECODE;
bc->len = INIT_BCODE_SIZE;
fprintf(stderr, "analyzing\n");
analyze(obj, &bc, &i, e, params, &d);
emit(&bc, &i, done_p ? OP_DONE : OP_RET);
/* fprintf(stderr, "shrinking\n"); */
shrink_bcode(&bc, i);
fprintf(stderr, "done compiling:\n");
print_bytecode(bc);
return bc;
}
sexp eval_in_stack(sexp obj, env e, sexp* stack, unsigned int top) {
bytecode bc = compile(SEXP_NULL, obj, e, 1);
fprintf(stderr, "evaling\n");
return vm(bc, e, stack, top);
}
sexp eval(sexp obj, env e) {
sexp* stack = (sexp*) malloc(sizeof(sexp) * INIT_STACK_SIZE);
sexp res = eval_in_stack(obj, e, stack, 0);
free(stack);
return res;
}
int main (int argc, char **argv) {
sexp obj, res, *stack;
env e;
sexp_init();
e = make_standard_env();
stack = (sexp*) malloc(sizeof(sexp) * INIT_STACK_SIZE);
/* repl */
fprintf(stdout, "> ");
fflush(stdout);
while ((obj = read_sexp(stdin)) != SEXP_EOF) {
write_sexp(stdout, obj);
fprintf(stdout, "\n => ");
res = eval_in_stack(obj, e, stack, 0);
/* fprintf(stderr, " (=> %d)\n", res); */
write_sexp(stdout, res);
fprintf(stdout, "\n> ");
fflush(stdout);
}
fprintf(stdout, "\n");
return 0;
}
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