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chibi-scheme/eval.c
Alex Shinn dfc38557b9 initial macro support
2009-03-11 15:48:18 +09:00

1230 lines
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/* eval.c -- evaluator library implementation */
/* Copyright (c) 2009 Alex Shinn. All rights reserved. */
/* BSD-style license: http://synthcode.com/license.txt */
#include "eval.h"
/************************************************************************/
static int scheme_initialized_p = 0;
static sexp cur_input_port, cur_output_port, cur_error_port;
static sexp exception_handler_cell;
static sexp continuation_resumer;
#if USE_DEBUG
#include "debug.c"
#else
#define print_stack(...)
#define print_bytecode(...)
#define disasm(...)
#endif
/********************** environment utilities ***************************/
static sexp env_cell(env e, sexp key) {
sexp ls;
do {
for (ls=e->bindings; SEXP_PAIRP(ls); ls=SEXP_CDR(ls))
if (SEXP_CAAR(ls) == key)
return SEXP_CAR(ls);
e = e->parent;
} while (e);
return NULL;
}
static int env_global_p (env e, sexp id) {
while (e->parent) {
if (sexp_assq(id, e->bindings) != SEXP_FALSE)
return 0;
else
e = e->parent;
}
return 1;
}
static void env_define(env e, sexp key, sexp value) {
sexp cell = env_cell(e, key);
if (cell) {
SEXP_CDR(cell) = value;
} else {
e->bindings = sexp_cons(sexp_cons(key, value), e->bindings);
}
}
static env extend_env_closure (env e, sexp fv, int offset) {
int i;
env e2 = (env) SEXP_ALLOC(sizeof(struct env));
e2->tag = SEXP_ENV;
e2->parent = e;
e2->bindings = SEXP_NULL;
for (i=offset; SEXP_PAIRP(fv); fv = SEXP_CDR(fv), i--)
e2->bindings = sexp_cons(sexp_cons(SEXP_CAR(fv), sexp_make_integer(i)),
e2->bindings);
return e2;
}
static int core_code (env e, sexp sym) {
sexp cell = env_cell(e, sym);
if (! cell || ! SEXP_COREP(SEXP_CDR(cell))) return 0;
return (((core_form)SEXP_CDR(cell))->code);
}
static sexp sexp_reverse_flatten_dot (sexp ls) {
sexp res;
for (res=SEXP_NULL; SEXP_PAIRP(ls); ls=SEXP_CDR(ls))
res = sexp_cons(SEXP_CAR(ls), res);
return (SEXP_NULLP(ls) ? res : sexp_cons(ls, res));
}
static sexp sexp_flatten_dot (sexp ls) {
return sexp_nreverse(sexp_reverse_flatten_dot(ls));
}
/************************* bytecode utilities ***************************/
static void shrink_bcode(bytecode *bc, unsigned int i) {
bytecode tmp;
if ((*bc)->len != i) {
/* fprintf(stderr, "shrinking to %d\n", i); */
tmp = (bytecode) SEXP_ALLOC(sizeof(struct bytecode) + i);
tmp->tag = SEXP_BYTECODE;
tmp->len = i;
memcpy(tmp->data, (*bc)->data, i);
SEXP_FREE(*bc);
*bc = tmp;
}
}
static 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) SEXP_ALLOC(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;
}
static void emit_word(bytecode *bc, unsigned int *i, sexp_uint_t val) {
bytecode tmp;
if ((*bc)->len < (*i)+4) {
tmp = (bytecode) SEXP_ALLOC(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);
}
#define emit_push(bc,i,obj) (emit(bc,i,OP_PUSH), emit_word(bc,i,(sexp_uint_t)obj))
static sexp sexp_make_procedure(char flags, unsigned short num_args,
sexp bc, sexp vars) {
procedure proc = SEXP_ALLOC(sizeof(struct procedure));
proc->tag = SEXP_PROCEDURE;
proc->flags = flags;
proc->num_args = num_args;
proc->bc = (bytecode) bc;
proc->vars = vars;
return (sexp) proc;
}
static sexp sexp_make_macro (procedure p, env e) {
macro mac = SEXP_ALLOC(sizeof(struct macro));
mac->tag = SEXP_MACRO;
mac->e = e;
mac->proc = p;
return (sexp) mac;
}
/************************* the compiler ***************************/
sexp sexp_expand_macro (macro mac, sexp form, env e) {
sexp res, *stack = SEXP_ALLOC(sizeof(sexp)*INIT_STACK_SIZE);
bytecode bc;
unsigned int i;
fprintf(stderr, "expanding: ");
sexp_write(form, cur_error_port);
fprintf(stderr, "\n => ");
bc = (bytecode) SEXP_ALLOC(sizeof(struct bytecode)+32);
bc->tag = SEXP_BYTECODE;
bc->len = 32;
emit_push(&bc, &i, mac->e);
emit_push(&bc, &i, e);
emit_push(&bc, &i, form);
emit_push(&bc, &i, mac->proc);
emit(&bc, &i, OP_CALL);
emit_word(&bc, &i, (sexp_uint_t) sexp_make_integer(3));
emit(&bc, &i, OP_DONE);
res = vm(bc, e, stack, 0);
sexp_write(res, cur_error_port);
fprintf(stderr, "\n");
SEXP_FREE(bc);
SEXP_FREE(stack);
return res;
}
void analyze(sexp obj, bytecode *bc, unsigned int *i, env e,
sexp params, sexp fv, sexp sv, unsigned int *d, int tailp) {
int tmp1, tmp2, tmp3;
env e2;
sexp o1, o2, cell;
loop:
if (SEXP_PAIRP(obj)) {
if (SEXP_SYMBOLP(SEXP_CAR(obj))) {
o1 = env_cell(e, SEXP_CAR(obj));
if (! o1) {
analyze_app(obj, bc, i, e, params, fv, sv, d, tailp);
return;
}
o1 = SEXP_CDR(o1);
if (SEXP_COREP(o1)) {
switch (((core_form)o1)->code) {
case CORE_LAMBDA:
analyze_lambda(SEXP_FALSE, SEXP_CADR(obj), SEXP_CDDR(obj),
bc, i, e, params, fv, sv, d, tailp);
break;
case CORE_DEFINE_SYNTAX:
env_define(e, SEXP_CADR(obj),
sexp_make_macro((procedure) eval(SEXP_CADDR(obj), e), e));
break;
case CORE_DEFINE:
if ((((core_form)o1)->code == CORE_DEFINE)
&& SEXP_PAIRP(SEXP_CADR(obj))) {
o2 = SEXP_CAR(SEXP_CADR(obj));
analyze_lambda(SEXP_CAR(SEXP_CADR(obj)),
SEXP_CDR(SEXP_CADR(obj)),
SEXP_CDDR(obj),
bc, i, e, params, fv, sv, d, 0);
} else {
o2 = SEXP_CADR(obj);
analyze(SEXP_CADDR(obj), bc, i, e, params, fv, sv, d, 0);
}
if (! e->parent) {
emit(bc, i, OP_GLOBAL_SET);
emit_word(bc, i, (sexp_uint_t) o2);
emit_push(bc, i, SEXP_UNDEF);
} else {
o1 = env_cell(e, o2);
if (! o1)
errx(1, "define in bad position: %p", o2);
emit(bc, i, OP_STACK_SET);
emit_word(bc, i, sexp_unbox_integer(SEXP_CDR(o1)));
}
(*d)++;
break;
case CORE_SET:
analyze(SEXP_CADDR(obj), bc, i, e, params, fv, sv, d, 0);
analyze_var_ref(SEXP_CADR(obj), bc, i, e, params, fv, SEXP_NULL, d);
emit(bc, i, OP_SET_CAR);
break;
case CORE_BEGIN:
for (o2 = SEXP_CDR(obj); SEXP_PAIRP(o2); o2 = SEXP_CDR(o2)) {
if (SEXP_PAIRP(SEXP_CDR(o2))) {
analyze(SEXP_CAR(o2), bc, i, e, params, fv, sv, d, 0);
emit(bc, i, OP_DROP);
} else
analyze(SEXP_CAR(o2), bc, i, e, params, fv, sv, d, tailp);
}
break;
case CORE_IF:
analyze(SEXP_CADR(obj), bc, i, e, params, fv, sv, d, 0);
emit(bc, i, OP_JUMP_UNLESS); /* jumps if test fails */
(*d)--;
tmp1 = *i;
emit(bc, i, 0);
analyze(SEXP_CADDR(obj), bc, i, e, params, fv, sv, d, tailp);
emit(bc, i, OP_JUMP);
(*d)--;
tmp2 = *i;
emit(bc, i, 0);
((signed char*) (*bc)->data)[tmp1] = (*i)-tmp1; /* patch */
if (SEXP_PAIRP(SEXP_CDDDR(obj))) {
analyze(SEXP_CADDDR(obj), bc, i, e, params, fv, sv, d, tailp);
} else {
emit_push(bc, i, SEXP_UNDEF);
(*d)++;
}
((signed char*) (*bc)->data)[tmp2] = (*i)-tmp2; /* patch */
break;
case CORE_QUOTE:
emit_push(bc, i, SEXP_CADR(obj));
(*d)++;
break;
default:
errx(1, "unknown core form: %s", ((core_form)o1)->code);
}
} else if (SEXP_OPCODEP(o1)) {
/* verify arity */
switch (((opcode)o1)->op_class) {
case OPC_TYPE_PREDICATE:
case OPC_PREDICATE:
case OPC_ARITHMETIC:
case OPC_ARITHMETIC_INV:
case OPC_ARITHMETIC_CMP:
case OPC_CONSTRUCTOR:
case OPC_ACCESSOR:
case OPC_GENERIC:
tmp1 = sexp_length(SEXP_CDR(obj));
if (tmp1 == 0) {
errx(1, "opcode with no arguments: %s", ((opcode)o1)->name);
} else if (tmp1 == 1) {
if (((opcode)o1)->op_class == OPC_ARITHMETIC_INV) {
analyze(SEXP_CADR(obj), bc, i, e, params, fv, sv, d, 0);
emit(bc, i, ((opcode)o1)->op_inverse);
} else {
analyze(SEXP_CADR(obj), bc, i, e, params, fv, sv, d, 0);
if (((opcode)o1)->op_class != OPC_ARITHMETIC) {
emit(bc, i, ((opcode)o1)->op_name);
(*d)--;
}
}
} else {
for (o2 = sexp_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, fv, sv, d, 0);
}
emit(bc, i, ((opcode)o1)->op_name);
(*d) -= (tmp1-1);
if (((opcode)o1)->op_class == OPC_ARITHMETIC) {
for (tmp1-=2; tmp1>0; tmp1--)
emit(bc, i, ((opcode)o1)->op_name);
}
}
break;
case OPC_IO:
tmp1 = sexp_length(SEXP_CDR(obj));
if (tmp1 == ((opcode)o1)->num_args && ((opcode)o1)->var_args_p) {
emit(bc, i, OP_PARAMETER);
emit_word(bc, i, (sexp_uint_t) ((opcode)o1)->data);
(*d)++;
}
for (o2 = sexp_reverse(SEXP_CDR(obj)); SEXP_PAIRP(o2);
o2 = SEXP_CDR(o2))
analyze(SEXP_CAR(o2), bc, i, e, params, fv, sv, d, 0);
emit(bc, i, ((opcode)o1)->op_name);
(*d) -= (tmp1-1);
break;
case OPC_PARAMETER:
emit(bc, i, ((opcode)o1)->op_name);
emit_word(bc, i, (sexp_uint_t) ((opcode)o1)->data);
break;
case OPC_FOREIGN:
for (o2 = sexp_reverse(SEXP_CDR(obj)); SEXP_PAIRP(o2);
o2 = SEXP_CDR(o2)) {
analyze(SEXP_CAR(o2), bc, i, e, params, fv, sv, d, 0);
}
emit_push(bc, i, ((opcode)o1)->data);
emit(bc, i, ((opcode)o1)->op_name);
(*d) -= sexp_length(SEXP_CDR(obj));
break;
default:
errx(1, "unknown opcode class: %d", ((opcode)o1)->op_class);
}
} else if (SEXP_MACROP(o1)) {
obj = sexp_expand_macro((macro) o1, obj, e);
goto loop;
} else {
/* general procedure call */
analyze_app(obj, bc, i, e, params, fv, sv, d, tailp);
}
} 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)
&& sexp_listp(SEXP_CADR(SEXP_CAR(obj)))) {
/* let */
tmp1 = sexp_length(SEXP_CADR(SEXP_CAR(obj)));
e2 = extend_env_closure(e, SEXP_CADR(SEXP_CAR(obj)), (*d));
for (o2=sexp_reverse(SEXP_CDR(obj)); SEXP_PAIRP(o2); o2=SEXP_CDR(o2))
analyze(SEXP_CAR(o2), bc, i, e, params, fv, sv, d, 0);
params = sexp_append(SEXP_CADR(SEXP_CAR(obj)), params);
for (o2=SEXP_CDDR(SEXP_CAR(obj)); SEXP_PAIRP(o2); o2=SEXP_CDR(o2)) {
if (SEXP_PAIRP(SEXP_CDR(o2))) {
analyze(SEXP_CAR(o2), bc, i, e2, params, fv, sv, d, 0);
emit(bc, i, OP_DROP);
} else {
analyze(SEXP_CAR(o2), bc, i, e2, params, fv, sv, d, tailp);
}
}
emit(bc, i, OP_STACK_SET);
emit_word(bc, i, tmp1+1);
(*d) -= tmp1;
for (tmp1; tmp1>0; tmp1--)
emit(bc, i, OP_DROP);
} else {
/* computed application */
analyze_app(obj, bc, i, e, params, fv, sv, d, tailp);
}
} else {
errx(1, "invalid operator: %s", SEXP_CAR(obj));
}
} else if (SEXP_SYMBOLP(obj)) {
analyze_var_ref(obj, bc, i, e, params, fv, sv, d);
} else { /* literal */
emit_push(bc, i, obj);
(*d)++;
}
}
void analyze_var_ref (sexp obj, bytecode *bc, unsigned int *i, env e,
sexp params, sexp fv, sexp sv, unsigned int *d) {
int tmp;
sexp o1;
/* fprintf(stderr, "symbol lookup, param length: %d sv: ", length(params)); */
/* sexp_write(sv, stderr); */
/* fprintf(stderr, "\n"); */
if ((tmp = sexp_list_index(params, obj)) >= 0) {
/* fprintf(stderr, "compiling local ref: %p => %d (d = %d)\n", obj, tmp, *d); */
o1 = env_cell(e, obj);
emit(bc, i, OP_STACK_REF);
emit_word(bc, i, *d - sexp_unbox_integer(SEXP_CDR(o1)));
} else if ((tmp = sexp_list_index(fv, obj)) >= 0) {
/* fprintf(stderr, "compiling closure ref: %p => %d\n", obj, tmp); */
emit(bc, i, OP_CLOSURE_REF);
emit_word(bc, i, (sexp_uint_t) sexp_make_integer(tmp));
} else {
/* fprintf(stderr, "compiling global ref: %p\n", obj); */
emit(bc, i, OP_GLOBAL_REF);
emit_word(bc, i, (sexp_uint_t) obj);
}
(*d)++;
if (sexp_list_index(sv, obj) >= 0) {
/* fprintf(stderr, "mutable variable, fetching CAR\n"); */
emit(bc, i, OP_CAR);
}
}
void analyze_app (sexp obj, bytecode *bc, unsigned int *i, env e,
sexp params, sexp fv, sexp sv, unsigned int *d, int tailp) {
sexp o1;
unsigned long len = sexp_length(SEXP_CDR(obj));
/* push the arguments onto the stack */
for (o1 = sexp_reverse(SEXP_CDR(obj)); SEXP_PAIRP(o1); o1 = SEXP_CDR(o1)) {
analyze(SEXP_CAR(o1), bc, i, e, params, fv, sv, d, 0);
}
/* push the operator onto the stack */
analyze(SEXP_CAR(obj), bc, i, e, params, fv, sv, d, 0);
/* maybe overwrite the current frame */
if (tailp) {
emit(bc, i, OP_TAIL_CALL);
emit_word(bc, i, (sexp_uint_t) sexp_make_integer(sexp_length(params)+(*d)));
emit_word(bc, i, (sexp_uint_t) sexp_make_integer(len));
} else {
/* normal call */
emit(bc, i, OP_CALL);
emit_word(bc, i, (sexp_uint_t) sexp_make_integer(len));
}
}
sexp free_vars (env e, sexp formals, sexp obj, sexp fv) {
sexp o1;
if (SEXP_SYMBOLP(obj)) {
if (env_global_p(e, obj)
|| (sexp_list_index(formals, obj) >= 0)
|| (sexp_list_index(fv, obj) >= 0))
return fv;
else
return sexp_cons(obj, fv);
} else if (SEXP_PAIRP(obj)) {
if (SEXP_SYMBOLP(SEXP_CAR(obj))) {
if ((o1 = env_cell(e, SEXP_CAR(obj)))
&& SEXP_COREP(o1)
&& (((core_form)SEXP_CDR(o1))->code == CORE_LAMBDA)) {
return free_vars(e, SEXP_CADR(obj), SEXP_CADDR(obj), fv);
}
}
while (SEXP_PAIRP(obj)) {
fv = free_vars(e, formals, SEXP_CAR(obj), fv);
obj = SEXP_CDR(obj);
}
return fv;
} else {
return fv;
}
}
sexp set_vars (env e, sexp formals, sexp obj, sexp sv) {
sexp tmp;
if (SEXP_NULLP(formals))
return sv;
if (SEXP_PAIRP(obj)) {
if (SEXP_SYMBOLP(SEXP_CAR(obj))) {
if ((tmp = env_cell(e, SEXP_CAR(obj))) && SEXP_COREP(SEXP_CDR(tmp))) {
if (((core_form)SEXP_CDR(tmp))->code == CORE_LAMBDA) {
formals = sexp_lset_diff(formals, SEXP_CADR(obj));
return set_vars(e, formals, SEXP_CADDR(obj), sv);
} else if (((core_form)SEXP_CDR(tmp))->code == CORE_SET
&& (sexp_list_index(formals, SEXP_CADR(obj)) >= 0)
&& ! (sexp_list_index(sv, SEXP_CADR(obj)) >= 0)) {
sv = sexp_cons(SEXP_CADR(obj), sv);
return set_vars(e, formals, SEXP_CADDR(obj), sv);
}
}
}
while (SEXP_PAIRP(obj)) {
sv = set_vars(e, formals, SEXP_CAR(obj), sv);
obj = SEXP_CDR(obj);
}
}
return sv;
}
void analyze_lambda (sexp name, sexp formals, sexp body,
bytecode *bc, unsigned int *i, env e,
sexp params, sexp fv, sexp sv, unsigned int *d,
int tailp) {
sexp obj, ls, flat_formals, fv2;
env e2;
int k;
flat_formals = sexp_flatten_dot(formals);
fv2 = free_vars(e, flat_formals, body, SEXP_NULL);
e2 = extend_env_closure(e, flat_formals, -4);
/* fprintf(stderr, "%d free-vars\n", sexp_length(fv2)); */
/* sexp_write(fv2, cur_error_port); */
/* fprintf(stderr, "\n"); */
/* compile the body with respect to the new params */
obj = (sexp) compile(flat_formals, body, e2, fv2, sv, 0);
/* push the closed vars */
emit_push(bc, i, SEXP_UNDEF);
emit_push(bc, i, sexp_make_integer(sexp_length(fv2)));
emit(bc, i, OP_MAKE_VECTOR);
(*d)++;
for (ls=fv2, k=0; SEXP_PAIRP(ls); ls=SEXP_CDR(ls), k++) {
analyze_var_ref(SEXP_CAR(ls), bc, i, e, params, fv, SEXP_NULL, d);
emit_push(bc, i, sexp_make_integer(k));
emit(bc, i, OP_STACK_REF);
emit_word(bc, i, 3);
emit(bc, i, OP_VECTOR_SET);
emit(bc, i, OP_DROP);
(*d)--;
}
/* push the additional procedure info and make the closure */
emit_push(bc, i, obj);
emit_push(bc, i, sexp_make_integer(sexp_length(formals)));
emit_push(bc, i, sexp_make_integer(sexp_listp(formals) ? 0 : 1));
emit(bc, i, OP_MAKE_PROCEDURE);
}
bytecode compile(sexp params, sexp obj, env e, sexp fv, sexp sv, int done_p) {
unsigned int i = 0, j, d = 0, core, define_ok=1;
bytecode bc = (bytecode) SEXP_ALLOC(sizeof(struct bytecode)+INIT_BCODE_SIZE);
sexp sv2 = set_vars(e, params, obj, SEXP_NULL), internals=SEXP_NULL, ls;
bc->tag = SEXP_BYTECODE;
bc->len = INIT_BCODE_SIZE;
/* box mutable vars */
for (ls=params; SEXP_PAIRP(ls); ls=SEXP_CDR(ls)) {
if ((j = sexp_list_index(sv2, SEXP_CAR(ls)) >= 0)) {
emit_push(&bc, &i, SEXP_NULL);
emit(&bc, &i, OP_STACK_REF);
emit_word(&bc, &i, j+4);
emit(&bc, &i, OP_CONS);
emit(&bc, &i, OP_STACK_SET);
emit_word(&bc, &i, j+4);
emit(&bc, &i, OP_DROP);
}
}
sv = sexp_append(sv2, sv);
/* determine internal defines */
if (e->parent) {
for (ls=SEXP_NULL; SEXP_PAIRP(obj); obj=SEXP_CDR(obj)) {
core = SEXP_PAIRP(SEXP_CAR(obj)) && SEXP_SYMBOLP(SEXP_CAAR(obj))
&& core_code(e, SEXP_CAAR(obj));
if (core == CORE_BEGIN) {
obj = sexp_cons(SEXP_CAR(obj),
sexp_append(SEXP_CDAR(obj), SEXP_CDR(obj)));
} else {
if (core == CORE_DEFINE) {
if (! define_ok)
errx(1, "definition in non-definition context: %p", obj);
internals = sexp_cons(SEXP_PAIRP(SEXP_CADAR(obj))
? SEXP_CAR(SEXP_CADAR(obj)) : SEXP_CADAR(obj),
internals);
} else {
define_ok = 0;
}
ls = sexp_cons(SEXP_CAR(obj), ls);
}
}
obj = sexp_reverse(ls);
/* sexp_write_string("internals: ", cur_error_port); */
/* sexp_write(internals, cur_error_port); */
/* sexp_write_string("\n", cur_error_port); */
j = sexp_length(internals);
if (SEXP_PAIRP(internals)) {
e = extend_env_closure(e, internals, 2);
params = sexp_append(internals, params);
for (ls=internals; SEXP_PAIRP(ls); ls=SEXP_CDR(ls))
emit_push(&bc, &i, (sexp_uint_t) SEXP_UNDEF);
d+=j;
}
}
/* analyze body sequence */
for ( ; SEXP_PAIRP(obj); obj=SEXP_CDR(obj)) {
if (SEXP_PAIRP(SEXP_CDR(obj))) {
analyze(SEXP_CAR(obj), &bc, &i, e, params, fv, sv, &d, 0);
emit(&bc, &i, OP_DROP);
} else {
analyze(SEXP_CAR(obj), &bc, &i, e, params, fv, sv, &d,
! done_p && ! SEXP_PAIRP(internals));
}
}
if (SEXP_PAIRP(internals)) {
emit(&bc, &i, OP_STACK_SET);
emit_word(&bc, &i, j+1);
for (j; j>0; j--)
emit(&bc, &i, OP_DROP);
}
emit(&bc, &i, done_p ? OP_DONE : OP_RET);
shrink_bcode(&bc, i);
print_bytecode(bc);
disasm(bc);
return bc;
}
/*********************** the virtual machine **************************/
sexp sexp_save_stack(sexp *stack, unsigned int to) {
sexp res, *data;
int i;
res = sexp_make_vector(to, SEXP_UNDEF);
data = sexp_vector_data(res);
for (i=0; i<to; i++)
data[i] = stack[i];
return res;
}
unsigned int sexp_restore_stack(sexp saved, sexp *current) {
int len = sexp_vector_length(saved), i;
sexp *from = sexp_vector_data(saved);
for (i=0; i<len; i++)
current[i] = from[i];
return len;
}
#define sexp_raise(exn) {stack[top++]=(exn); goto call_error_handler;}
sexp vm(bytecode bc, env e, sexp* stack, unsigned int top) {
unsigned char *ip=bc->data;
sexp cp=SEXP_UNDEF, tmp1, tmp2;
int i, j, k;
loop:
/* fprintf(stderr, "OP: %s (%d)\n", (*ip<=71) ? reverse_opcode_names[*ip] : "<unknown>", *ip); */
switch (*ip++) {
case OP_NOOP:
fprintf(stderr, "noop\n");
break;
case OP_GLOBAL_REF:
tmp1 = env_cell(e, ((sexp*)ip)[0]);
if (! tmp1)
sexp_raise(sexp_intern("undefined-variable"));
stack[top++]=SEXP_CDR(tmp1);
ip += sizeof(sexp);
break;
case OP_GLOBAL_SET:
env_define(e, ((sexp*)ip)[0], stack[--top]);
ip += sizeof(sexp);
break;
case OP_STACK_REF:
/* fprintf(stderr, "stack-ref: %d => ", (sexp_sint_t) ((sexp*)ip)[0]); */
/* sexp_write(stack[top - (sexp_sint_t) ((sexp*)ip)[0]], cur_error_port); */
/* fprintf(stderr, "\n"); */
stack[top] = stack[top - (sexp_sint_t) ((sexp*)ip)[0]];
ip += sizeof(sexp);
top++;
break;
case OP_STACK_SET:
/* print_stack(stack, top); */
/* fprintf(stderr, "stack-set: %d => ", (sexp_sint_t) ((sexp*)ip)[0]); */
/* sexp_write(stack[top-1], cur_error_port); */
/* fprintf(stderr, "\n"); */
stack[top - (sexp_sint_t) ((sexp*)ip)[0]] = stack[top-1];
stack[top-1] = SEXP_UNDEF;
/* print_stack(stack, top); */
ip += sizeof(sexp);
break;
case OP_CLOSURE_REF:
/* fprintf(stderr, "closure-ref: %d => ", sexp_unbox_integer(((sexp*)ip)[0])); */
/* sexp_write(sexp_vector_ref(cp, ((sexp*)ip)[0]), cur_error_port); */
/* fprintf(stderr, "\n"); */
stack[top++]=sexp_vector_ref(cp, ((sexp*)ip)[0]);
ip += sizeof(sexp);
break;
case OP_VECTOR_REF:
stack[top-2]=sexp_vector_ref(stack[top-1], stack[top-2]);
top--;
break;
case OP_VECTOR_SET:
sexp_vector_set(stack[top-1], stack[top-2], stack[top-3]);
stack[top-3]=SEXP_UNDEF;
/* fprintf(stderr, "vector-set: %d => ", sexp_unbox_integer(stack[top-2])); */
/* sexp_write(stack[top-1], cur_error_port); */
/* fprintf(stderr, "\n"); */
top-=2;
break;
case OP_STRING_REF:
stack[top-2]=sexp_string_ref(stack[top-1], stack[top-2]);
top--;
break;
case OP_STRING_SET:
sexp_string_set(stack[top-1], stack[top-2], stack[top-3]);
stack[top-3]=SEXP_UNDEF;
top-=2;
break;
case OP_MAKE_PROCEDURE:
stack[top-4]=sexp_make_procedure((int) stack[top-1], (int) stack[top-2], stack[top-3], stack[top-4]);
top-=3;
break;
case OP_MAKE_VECTOR:
stack[top-2]=sexp_make_vector(sexp_unbox_integer(stack[top-1]), stack[top-2]);
top--;
break;
case OP_PUSH:
/* fprintf(stderr, "pushing: "); */
/* sexp_write(((sexp*)ip)[0], cur_error_port); */
/* fprintf(stderr, "\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:
tmp1 = stack[top-2];
stack[top-2]=stack[top-1];
stack[top-1]=tmp1;
break;
case OP_PARAMETER:
stack[top] = *(sexp*)((sexp*)ip)[0];
top++;
ip += sizeof(sexp);
break;
case OP_PAIRP:
stack[top-1]=SEXP_PAIRP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_NULLP:
stack[top-1]=SEXP_NULLP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_CHARP:
stack[top-1]=SEXP_CHARP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_INTEGERP:
stack[top-1]=SEXP_INTEGERP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_SYMBOLP:
stack[top-1]=SEXP_SYMBOLP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_STRINGP:
stack[top-1]=SEXP_STRINGP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_VECTORP:
stack[top-1]=SEXP_VECTORP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_PROCEDUREP:
stack[top-1]=SEXP_PROCEDUREP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_IPORTP:
stack[top-1]=SEXP_IPORTP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_OPORTP:
stack[top-1]=SEXP_OPORTP(stack[top-1]) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_EOFP:
stack[top-1]=(stack[top-1] == SEXP_EOF) ? SEXP_TRUE : SEXP_FALSE; break;
case OP_CAR:
if (! SEXP_PAIRP(stack[top-1])) sexp_raise(sexp_intern("not-a-pair"));
stack[top-1]=SEXP_CAR(stack[top-1]); break;
case OP_CDR:
if (! SEXP_PAIRP(stack[top-1])) sexp_raise(sexp_intern("not-a-pair"));
stack[top-1]=SEXP_CDR(stack[top-1]); break;
case OP_SET_CAR:
if (! SEXP_PAIRP(stack[top-1])) sexp_raise(sexp_intern("not-a-pair"));
SEXP_CAR(stack[top-1]) = stack[top-2];
stack[top-2]=SEXP_UNDEF;
top--;
break;
case OP_SET_CDR:
if (! SEXP_PAIRP(stack[top-1])) sexp_raise(sexp_intern("not-a-pair"));
SEXP_CDR(stack[top-1]) = stack[top-2];
stack[top-2]=SEXP_UNDEF;
top--;
break;
case OP_CONS:
stack[top-2]=sexp_cons(stack[top-1], stack[top-2]);
top--;
break;
case OP_ADD:
stack[top-2]=sexp_add(stack[top-1],stack[top-2]);
top--;
break;
case OP_SUB:
stack[top-2]=sexp_sub(stack[top-1],stack[top-2]);
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_LE:
stack[top-2]=((stack[top-2] <= stack[top-1]) ? SEXP_TRUE : SEXP_FALSE);
top--;
break;
case OP_GT:
stack[top-2]=((stack[top-2] > stack[top-1]) ? SEXP_TRUE : SEXP_FALSE);
top--;
break;
case OP_GE:
stack[top-2]=((stack[top-2] >= stack[top-1]) ? SEXP_TRUE : SEXP_FALSE);
top--;
break;
case OP_EQ:
case OP_EQN:
stack[top-2]=((stack[top-1] == stack[top-2]) ? SEXP_TRUE : SEXP_FALSE);
top--;
break;
case OP_TAIL_CALL:
j = sexp_unbox_integer(((sexp*)ip)[0]); /* current depth */
ip += sizeof(sexp);
i = sexp_unbox_integer(((sexp*)ip)[0]); /* number of params */
tmp1 = stack[top-1]; /* procedure to call */
/* fprintf(stderr, "tail call: depth=%d, i=%d, top=%d\n", j, i, top); */
/* print_stack(stack, top); */
/* save frame info */
stack[top] = stack[top-i-j];
stack[top+1] = stack[top-i-j+1];
/* copy new args into place */
for (k=top-i-1; k<top-1; k++)
stack[k-j-i] = stack[k];
/* restore frame info */
stack[top-j-i] = stack[top];
stack[top-j-i+1] = stack[top+1];
top -= (j-i-1);
stack[top-1] = tmp1;
/* print_stack(stack, top); */
/* exit(0); */
/* sexp_debug("call proc: ", tmp1); */
/* sexp_debug("bc: ", sexp_procedure_code(tmp1)); */
/* fprintf(stderr, "data: %p\n", sexp_procedure_code(tmp1)->data); */
bc = sexp_procedure_code(tmp1);
ip = bc->data;
cp = sexp_procedure_vars(tmp1);
break;
case OP_CALL:
if (top >= INIT_STACK_SIZE)
errx(1, "out of stack space: %d", top);
/* fprintf(stderr, "CALL\n"); */
/* print_stack(stack, top); */
i = sexp_unbox_integer(((sexp*)ip)[0]);
tmp1 = stack[top-1];
if (! SEXP_PROCEDUREP(tmp1)) {
fprintf(stderr, "error: non-procedure app\n");
sexp_raise(sexp_intern("non-procedure-application"));
}
j = i - sexp_unbox_integer(sexp_procedure_num_args(tmp1));
if (j < 0)
sexp_raise(sexp_intern("not-enough-args"));
if (j > 0) {
if (sexp_procedure_variadic_p(tmp1)) {
stack[top-i-1] = sexp_cons(stack[top-i-1], SEXP_NULL);
for (k=top-i; k<top-(i-j)-1; k++)
stack[top-i-1] = sexp_cons(stack[k], stack[top-i-1]);
for ( ; k<top; k++)
stack[k-j+1] = stack[k];
top -= (j-1);
i-=(j-1);
} else {
fprintf(stderr, "got: %d, expected: %d\n", i, sexp_procedure_num_args(tmp1));
sexp_raise(sexp_intern("too-many-args"));
}
} else if (sexp_procedure_variadic_p(tmp1)) {
/* shift stack, set extra arg to null */
for (k=top; k>=top-i; k--)
stack[k] = stack[k-1];
stack[top-i-1] = SEXP_NULL;
top++;
i++;
}
stack[top-1] = sexp_make_integer(i);
stack[top] = sexp_make_integer(ip+4);
stack[top+1] = cp;
top+=2;
/* sexp_debug("call proc: ", tmp1); */
/* sexp_debug("bc: ", sexp_procedure_code(tmp1)); */
/* fprintf(stderr, "data: %p\n", sexp_procedure_code(tmp1)->data); */
bc = sexp_procedure_code(tmp1);
/* print_bytecode(bc); */
/* disasm(bc); */
ip = bc->data;
cp = sexp_procedure_vars(tmp1);
/* fprintf(stderr, "... calling procedure at %p\ncp: ", ip); */
/* /\* sexp_write(cp, stderr); *\/ */
/* fprintf(stderr, "\n"); */
/* fprintf(stderr, "stack at %d\n", top); */
/* print_stack(stack, top); */
break;
case OP_APPLY1:
tmp1 = stack[top-1];
if (! SEXP_PROCEDUREP(tmp1))
errx(2, "non-procedure application: %p", tmp1);
tmp2 = stack[top-2];
i = sexp_length(tmp2);
top += (i-2);
for ( ; SEXP_PAIRP(tmp2); tmp2=SEXP_CDR(tmp2), top--)
stack[top-1] = SEXP_CAR(tmp2);
top += i+3;
stack[top-3] = sexp_make_integer(i);
stack[top-2] = sexp_make_integer(ip);
stack[top-1] = cp;
bc = sexp_procedure_code(tmp1);
ip = bc->data;
cp = sexp_procedure_vars(tmp1);
break;
case OP_CALLCC:
tmp1 = stack[top-1];
if (! SEXP_PROCEDUREP(tmp1))
errx(2, "non-procedure application: %p", tmp1);
stack[top] = sexp_make_integer(1);
stack[top+1] = sexp_make_integer(ip);
stack[top+2] = cp;
tmp2 = sexp_save_stack(stack, top+3);
/* fprintf(stderr, "saved: ", top); */
/* sexp_write(tmp2, cur_error_port); */
/* fprintf(stderr, "\n", top); */
stack[top-1] = sexp_make_procedure(0, (int) sexp_make_integer(1),
continuation_resumer,
sexp_vector(1, tmp2));
top+=3;
bc = sexp_procedure_code(tmp1);
ip = bc->data;
cp = sexp_procedure_vars(tmp1);
break;
case OP_RESUMECC:
/* fprintf(stderr, "resuming continuation (%d)\n", top); */
/* print_stack(stack, top); */
/* sexp_write(sexp_vector_ref(cp, 0), cur_error_port); */
/* fprintf(stderr, "\n"); */
tmp1 = stack[top-4];
top = sexp_restore_stack(sexp_vector_ref(cp, 0), stack);
/* fprintf(stderr, "... restored stack (%d):\n", top); */
/* print_stack(stack, top); */
cp = stack[top-1];
ip = (unsigned char*) sexp_unbox_integer(stack[top-2]);
i = sexp_unbox_integer(stack[top-3]);
top -= 3;
stack[top-1] = tmp1;
break;
case OP_ERROR:
call_error_handler:
fprintf(stderr, "in error handler\n");
sexp_write_string("ERROR: ", cur_error_port);
sexp_write(stack[top-1], cur_error_port);
sexp_write_string("\n", cur_error_port);
tmp1 = SEXP_CDR(exception_handler_cell);
stack[top-1] = SEXP_UNDEF;
stack[top] = (sexp) 1;
stack[top+1] = sexp_make_integer(ip+4);
stack[top+2] = cp;
top+=3;
bc = sexp_procedure_code(tmp1);
ip = bc->data;
cp = sexp_procedure_vars(tmp1);
break;
case OP_FCALL0:
stack[top-1]=((sexp_proc0)stack[top-1])();
break;
case OP_FCALL1:
stack[top-2]=((sexp_proc1)stack[top-1])(stack[top-2]);
top--;
break;
case OP_FCALL2:
stack[top-3]=((sexp_proc2)stack[top-1])(stack[top-2],stack[top-3]);
top-=2;
break;
case OP_FCALL3:
stack[top-4]=((sexp_proc3)stack[top-1])(stack[top-2],stack[top-3],stack[top-4]);
top-=3;
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 failed, jumping to + %d => %p\n", ((signed char*)ip)[0], ip + ((signed char*)ip)[0]); */
ip += ((signed char*)ip)[0];
} else {
/* fprintf(stderr, "test passed, not jumping\n"); */
ip++;
}
break;
case OP_JUMP:
/* fprintf(stderr, "jumping to + %d => %p\n", ((signed char*)ip)[0], ip + ((signed char*)ip)[0]); */
ip += ((signed char*)ip)[0];
break;
case OP_DISPLAY:
if (SEXP_STRINGP(stack[top-1])) {
sexp_write_string(sexp_string_data(stack[top-1]), stack[top-2]);
break;
}
case OP_WRITE:
sexp_write(stack[top-1], stack[top-2]);
stack[top-2] = SEXP_UNDEF;
top--;
break;
case OP_WRITE_CHAR:
sexp_write_char(sexp_unbox_character(stack[top-1]), stack[top-2]);
break;
case OP_NEWLINE:
sexp_write_char('\n', stack[top-1]);
stack[top-1] = SEXP_UNDEF;
break;
case OP_FLUSH_OUTPUT:
sexp_flush(stack[top-1]);
stack[top-1] = SEXP_UNDEF;
break;
case OP_READ:
stack[top-1] = sexp_read(stack[top-1]);
if (stack[top-1] == SEXP_ERROR) sexp_raise(sexp_intern("read-error"));
break;
case OP_READ_CHAR:
i = sexp_read_char(stack[top-1]);
stack[top-1] = (i == EOF) ? SEXP_EOF : sexp_make_character(i);
break;
case OP_RET:
/* fprintf(stderr, "returning @ %d: ", top-1); */
/* fflush(stderr); */
/* sexp_write(stack[top-1], cur_error_port); */
/* fprintf(stderr, "...\n"); */
/* print_stack(stack, top); */
if (top<4)
goto end_loop;
cp = stack[top-2];
ip = (unsigned char*) sexp_unbox_integer(stack[top-3]);
i = sexp_unbox_integer(stack[top-4]);
stack[top-i-4] = stack[top-1];
top = top-i-3;
/* fprintf(stderr, "... done returning\n"); */
break;
case OP_DONE:
fprintf(stderr, "finally returning @ %d: ", top-1);
fflush(stderr);
sexp_write(stack[top-1], cur_error_port);
fprintf(stderr, "\n");
goto end_loop;
default:
fprintf(stderr, "unknown opcode: %d\n", *(ip-1));
stack[top] = SEXP_ERROR;
goto end_loop;
}
/* print_stack(stack, top); */
goto loop;
end_loop:
return stack[top-1];
}
/*********************** standard environment *************************/
static const struct core_form core_forms[] = {
{SEXP_CORE, CORE_DEFINE, "define"},
{SEXP_CORE, CORE_SET, "set!"},
{SEXP_CORE, CORE_LAMBDA, "lambda"},
{SEXP_CORE, CORE_IF, "if"},
{SEXP_CORE, CORE_BEGIN, "begin"},
{SEXP_CORE, CORE_QUOTE, "quote"},
{SEXP_CORE, CORE_DEFINE_SYNTAX, "define-syntax"},
{SEXP_CORE, CORE_LET_SYNTAX, "let-syntax"},
{SEXP_CORE, CORE_LETREC_SYNTAX, "letrec-syntax"},
};
static const struct opcode opcodes[] = {
#define _OP(c,o,n,m,t,u,i,s) {SEXP_OPCODE, c, o, n, m, t, u, i, s, NULL, NULL}
#define _FN(o,n,t,u,s,f) {SEXP_OPCODE, OPC_FOREIGN, o, n, 0, t,u, 0, s, (sexp)f, NULL}
#define _FN0(s, f) _FN(OP_FCALL0, 0, 0, 0, s, f)
#define _FN1(t, s, f) _FN(OP_FCALL1, 1, t, 0, s, f)
#define _FN2(t, u, s, f) _FN(OP_FCALL2, 2, t, u, s, f)
#define _PARAM(n,a,t) {SEXP_OPCODE, OPC_PARAMETER, OP_PARAMETER, 0, 1, t, 0, 0, n, a, NULL}
_OP(OPC_ACCESSOR, OP_CAR, 1, 0, SEXP_PAIR, 0, 0, "car"),
_OP(OPC_ACCESSOR, OP_SET_CAR, 2, 0, SEXP_PAIR, 0, 0, "set-car!"),
_OP(OPC_ACCESSOR, OP_CDR, 1, 0, SEXP_PAIR, 0, 0, "cdr"),
_OP(OPC_ACCESSOR, OP_SET_CDR, 2, 0, SEXP_PAIR, 0, 0, "set-cdr!"),
_OP(OPC_ACCESSOR, OP_VECTOR_REF,2,0, SEXP_VECTOR, SEXP_FIXNUM, 0,"vector-ref"),
_OP(OPC_ACCESSOR, OP_VECTOR_SET,3,0, SEXP_VECTOR, SEXP_FIXNUM, 0,"vector-set!"),
_OP(OPC_ACCESSOR, OP_STRING_REF,2,0, SEXP_STRING, SEXP_FIXNUM, 0,"string-ref"),
_OP(OPC_ACCESSOR, OP_STRING_SET,3,0, SEXP_STRING, SEXP_FIXNUM, 0,"string-set!"),
_OP(OPC_ARITHMETIC, OP_ADD, 0, 1, SEXP_FIXNUM, 0, 0, "+"),
_OP(OPC_ARITHMETIC, OP_MUL, 0, 1, SEXP_FIXNUM, 0, 0, "*"),
_OP(OPC_ARITHMETIC_INV, OP_SUB, 0, 1, SEXP_FIXNUM, 0, OP_NEG, "-"),
_OP(OPC_ARITHMETIC_INV, OP_DIV, 0, 1, SEXP_FIXNUM, 0, OP_INV, "/"),
_OP(OPC_ARITHMETIC, OP_MOD, 2, 0, SEXP_FIXNUM, SEXP_FIXNUM, 0, "%"),
_OP(OPC_ARITHMETIC_CMP, OP_LT, 0, 1, SEXP_FIXNUM, 0, 0, "<"),
_OP(OPC_ARITHMETIC_CMP, OP_LE, 0, 1, SEXP_FIXNUM, 0, 0, "<="),
_OP(OPC_ARITHMETIC_CMP, OP_GT, 0, 1, SEXP_FIXNUM, 0, 0, ">"),
_OP(OPC_ARITHMETIC_CMP, OP_GE, 0, 1, SEXP_FIXNUM, 0, 0, ">="),
_OP(OPC_ARITHMETIC_CMP, OP_EQN, 0, 1, SEXP_FIXNUM, 0, 0, "="),
_OP(OPC_PREDICATE, OP_EQ, 2, 0, 0, 0, 0, "eq?"),
_OP(OPC_CONSTRUCTOR, OP_CONS, 2, 0, 0, 0, 0, "cons"),
_OP(OPC_CONSTRUCTOR, OP_MAKE_VECTOR, 2, 0, SEXP_FIXNUM, 0, 0, "make-vector"),
_OP(OPC_CONSTRUCTOR, OP_MAKE_PROCEDURE, 4, 0, 0, 0, 0, "make-procedure"),
_OP(OPC_TYPE_PREDICATE, OP_PAIRP, 1, 0, 0, 0, 0, "pair?"),
_OP(OPC_TYPE_PREDICATE, OP_NULLP, 1, 0, 0, 0, 0, "null?"),
_OP(OPC_TYPE_PREDICATE, OP_STRINGP, 1, 0, 0, 0, 0, "string?"),
_OP(OPC_TYPE_PREDICATE, OP_SYMBOLP, 1, 0, 0, 0, 0, "symbol?"),
_OP(OPC_TYPE_PREDICATE, OP_CHARP, 1, 0, 0, 0, 0, "char?"),
_OP(OPC_TYPE_PREDICATE, OP_VECTORP, 1, 0, 0, 0, 0, "vector?"),
_OP(OPC_TYPE_PREDICATE, OP_PROCEDUREP, 1, 0, 0, 0, 0, "procedure?"),
_OP(OPC_TYPE_PREDICATE, OP_IPORTP, 1, 0, 0, 0, 0, "input-port?"),
_OP(OPC_TYPE_PREDICATE, OP_OPORTP, 1, 0, 0, 0, 0, "output-port?"),
_OP(OPC_TYPE_PREDICATE, OP_EOFP, 1, 0, 0, 0, 0, "eof-object?"),
_OP(OPC_GENERIC, OP_APPLY1, 2, 0, SEXP_PROCEDURE, SEXP_PAIR, 0, "apply1"),
_OP(OPC_GENERIC, OP_CALLCC, 1, SEXP_PROCEDURE, 0, 0, 0, "call-with-current-continuation"),
_OP(OPC_GENERIC, OP_ERROR, 1, SEXP_STRING, 0, 0, 0, "error"),
{SEXP_OPCODE, OPC_IO, OP_WRITE, 1, 1, 0, SEXP_OPORT, 0, "write", (sexp)&cur_output_port, NULL},
{SEXP_OPCODE, OPC_IO, OP_DISPLAY, 1, 1, 0, SEXP_OPORT, 0, "display", (sexp)&cur_output_port, NULL},
{SEXP_OPCODE, OPC_IO, OP_WRITE_CHAR, 1, 1, 0, SEXP_OPORT, 0, "write-char", (sexp)&cur_output_port, NULL},
{SEXP_OPCODE, OPC_IO, OP_NEWLINE, 0, 1, 0, SEXP_OPORT, 0, "newline", (sexp)&cur_output_port, NULL},
{SEXP_OPCODE, OPC_IO, OP_FLUSH_OUTPUT, 0, 1, 0, SEXP_OPORT, 0, "flush-output", (sexp)&cur_output_port, NULL},
{SEXP_OPCODE, OPC_IO, OP_READ, 0, 1, 0, SEXP_IPORT, 0, "read", (sexp)&cur_input_port, NULL},
{SEXP_OPCODE, OPC_IO, OP_READ_CHAR, 0, 1, 0, SEXP_IPORT, 0, "read-char", (sexp)&cur_input_port, NULL},
_FN1(SEXP_PAIR, "reverse", sexp_reverse),
_FN1(SEXP_PAIR, "list->vector", sexp_list_to_vector),
_FN2(0, SEXP_PAIR, "memq", sexp_memq),
_FN2(0, SEXP_PAIR, "assq", sexp_assq),
_FN2(SEXP_PAIR, SEXP_PAIR, "diffq", sexp_lset_diff),
_PARAM("current-input-port", (sexp)&cur_input_port, SEXP_IPORT),
_PARAM("current-output-port", (sexp)&cur_output_port, SEXP_OPORT),
_PARAM("current-error-port", (sexp)&cur_error_port, SEXP_OPORT),
#undef _OP
#undef _FN
#undef _FN0
#undef _FN1
#undef _FN2
#undef _PARAM
};
env make_standard_env() {
int i;
env e = (env) SEXP_ALLOC(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, sexp_intern(core_forms[i].name), (sexp)(&core_forms[i]));
}
for (i=0; i<(sizeof(opcodes)/sizeof(struct opcode)); i++) {
env_define(e, sexp_intern(opcodes[i].name), (sexp)(&opcodes[i]));
}
return e;
}
/************************** eval interface ****************************/
sexp eval_in_stack(sexp obj, env e, sexp* stack, unsigned int top) {
bytecode bc;
bc = compile(SEXP_NULL, sexp_cons(obj, SEXP_NULL), e, SEXP_NULL, SEXP_NULL, 1);
return vm(bc, e, stack, top);
}
sexp eval(sexp obj, env e) {
sexp* stack = (sexp*) SEXP_ALLOC(sizeof(sexp) * INIT_STACK_SIZE);
sexp res = eval_in_stack(obj, e, stack, 0);
SEXP_FREE(stack);
return res;
}
void scheme_init() {
bytecode bc;
unsigned int i=0;
if (! scheme_initialized_p) {
scheme_initialized_p = 1;
sexp_init();
cur_input_port = sexp_make_input_port(stdin);
cur_output_port = sexp_make_output_port(stdout);
cur_error_port = sexp_make_output_port(stderr);
bc = (bytecode) SEXP_ALLOC(sizeof(struct bytecode)+16);
bc->tag = SEXP_BYTECODE;
bc->len = 16;
emit(&bc, &i, OP_RESUMECC);
continuation_resumer = (sexp) bc;
}
}
void repl (env e, sexp *stack) {
sexp obj, res;
while (1) {
sexp_write_string("> ", cur_output_port);
sexp_flush(cur_output_port);
obj = sexp_read(cur_input_port);
if (obj == SEXP_EOF)
break;
res = eval_in_stack(obj, e, stack, 0);
if (res != SEXP_UNDEF) {
sexp_write(res, cur_output_port);
sexp_write_char('\n', cur_output_port);
}
}
}
int main (int argc, char **argv) {
sexp obj, res, in, out, *stack, err_handler, err_handler_sym;
env e;
bytecode bc;
unsigned int i, quit=0;
scheme_init();
stack = (sexp*) SEXP_ALLOC(sizeof(sexp) * INIT_STACK_SIZE);
e = make_standard_env();
bc = (bytecode) SEXP_ALLOC(sizeof(struct bytecode)+16);
bc->tag = SEXP_BYTECODE;
bc->len = 16;
i = 0;
emit_push(&bc, &i, (sexp_uint_t) SEXP_UNDEF);
emit(&bc, &i, OP_DONE);
err_handler = sexp_make_procedure(0, 0, (sexp)bc, sexp_make_vector(0, SEXP_UNDEF));
err_handler_sym = sexp_intern("*error-handler*");
env_define(e, err_handler_sym, err_handler);
exception_handler_cell = env_cell(e, err_handler_sym);
fprintf(stderr, "current-input-port: %d => %d\n", &cur_input_port, cur_input_port);
/* parse options */
for (i=1; i < argc && argv[i][0] == '-'; i++) {
switch (argv[i][1]) {
case 'e':
case 'p':
obj = sexp_read_from_string(argv[i+1]);
res = eval_in_stack(obj, e, stack, 0);
if (argv[i][1] == 'p') {
sexp_write(res, cur_output_port);
sexp_write_char('\n', cur_output_port);
}
quit=1;
i++;
break;
default:
errx(1, "unknown option: %s", argv[i]);
}
}
if (! quit) repl(e, stack);
return 0;
}
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