expr replace_visitor::visit_let(expr const & e) {
lean_assert(is_let(e));
expr new_t = visit(let_type(e));
expr new_v = visit(let_value(e));
expr new_b = visit(let_body(e));
return update_let(e, new_t, new_v, new_b);
}
expr dsimplify_core_fn::visit_let(expr const & e) {
if (m_cfg.m_zeta) {
return visit(instantiate(let_body(e), let_value(e)));
} else {
type_context::tmp_locals locals(m_ctx);
expr b = e;
bool modified = false;
while (is_let(b)) {
expr t = instantiate_rev(let_type(b), locals.size(), locals.data());
expr v = instantiate_rev(let_value(b), locals.size(), locals.data());
expr new_t = visit(t);
expr new_v = visit(v);
if (!is_eqp(t, new_t) || !is_eqp(v, new_v)) modified = true;
locals.push_let(let_name(b), new_t, new_v);
b = let_body(b);
}
b = instantiate_rev(b, locals.size(), locals.data());
expr new_b = visit(b);
if (!is_eqp(b, new_b)) modified = true;
if (modified)
return locals.mk_lambda(new_b);
else
return e;
}
}
expr compiler_step_visitor::visit_lambda_let(expr const & e) {
type_context::tmp_locals locals(m_ctx);
expr t = e;
while (true) {
/* Types are ignored in compilation steps. So, we do not invoke visit for d. */
if (is_lambda(t)) {
expr d = instantiate_rev(binding_domain(t), locals.size(), locals.data());
locals.push_local(binding_name(t), d, binding_info(t));
t = binding_body(t);
} else if (is_let(t)) {
expr d = instantiate_rev(let_type(t), locals.size(), locals.data());
expr v = visit(instantiate_rev(let_value(t), locals.size(), locals.data()));
locals.push_let(let_name(t), d, v);
t = let_body(t);
} else {
break;
}
}
t = instantiate_rev(t, locals.size(), locals.data());
t = visit(t);
return copy_tag(e, locals.mk_lambda(t));
}
data_t *eval(const data_t *exp, data_t *env) {
if(eval_plz_die) {
eval_plz_die = 0;
ExitThread(0);
}
if(is_self_evaluating(exp))
return (data_t*)exp;
if(is_variable(exp))
return lookup_variable_value(exp, env);
if(is_quoted_expression(exp))
return get_text_of_quotation(exp);
if(is_assignment(exp))
return eval_assignment(exp, env);
if(is_definition(exp))
return eval_definition(exp, env);
if(is_if(exp))
return eval_if(exp, env);
if(is_lambda(exp))
return make_procedure(get_lambda_parameters(exp), get_lambda_body(exp), env);
if(is_begin(exp))
return eval_sequence(get_begin_actions(exp), env);
if(is_cond(exp))
return eval(cond_to_if(exp), env);
if(is_letrec(exp))
return eval(letrec_to_let(exp), env);
if(is_let_star(exp))
return eval(let_star_to_nested_lets(exp), env);
if(is_let(exp))
return eval(let_to_combination(exp), env);
if(is_application(exp))
return apply(
eval(get_operator(exp), env),
get_list_of_values(get_operands(exp), env));
printf("Unknown expression type -- EVAL '");
return make_symbol("error");
}
object *eval(object *exp, object *env) {
object *procedure;
object *arguments;
object *result;
bool tailcall = false;
do {
if (is_self_evaluating(exp))
return exp;
if (is_variable(exp))
return lookup_variable_value(exp, env);
if (is_quoted(exp))
return text_of_quotation(exp);
if (is_assignment(exp))
return eval_assignment(exp, env);
if (is_definition(exp))
return eval_definition(exp, env);
if (is_if(exp)) {
exp = is_true(eval(if_predicate(exp), env)) ? if_consequent(exp) : if_alternative(exp);
tailcall = true;
continue;
}
if (is_lambda(exp))
return make_compound_proc(lambda_parameters(exp), lambda_body(exp), env);
if (is_begin(exp)) {
exp = begin_actions(exp);
while (!is_last_exp(exp)) {
eval(first_exp(exp), env);
exp = rest_exps(exp);
}
exp = first_exp(exp);
tailcall = true;
continue;
}
if (is_cond(exp)) {
exp = cond_to_if(exp);
tailcall = true;
continue;
}
if (is_let(exp)) {
exp = let_to_application(exp);
tailcall = true;
continue;
}
if (is_and(exp)) {
exp = and_tests(exp);
if (is_empty(exp))
return make_boolean(true);
while (!is_last_exp(exp)) {
result = eval(first_exp(exp), env);
if (is_false(result))
return result;
exp = rest_exps(exp);
}
exp = first_exp(exp);
tailcall = true;
continue;
}
if (is_or(exp)) {
exp = or_tests(exp);
if (is_empty(exp)) {
return make_boolean(false);
}
while (!is_last_exp(exp)) {
result = eval(first_exp(exp), env);
if (is_true(result))
return result;
exp = rest_exps(exp);
}
exp = first_exp(exp);
tailcall = true;
continue;
}
if (is_application(exp)) {
procedure = eval(operator(exp), env);
arguments = list_of_values(operands(exp), env);
if (is_primitive_proc(procedure) && procedure->data.primitive_proc.fn == eval_proc) {
exp = eval_expression(arguments);
env = eval_environment(arguments);
tailcall = true;
continue;
}
if (is_primitive_proc(procedure) && procedure->data.primitive_proc.fn == apply_proc) {
procedure = apply_operator(arguments);
arguments = apply_operands(arguments);
}
if (is_primitive_proc(procedure))
return (procedure->data.primitive_proc.fn)(arguments);
if (is_compound_proc(procedure)) {
env = extend_environment(procedure->data.compound_proc.parameters, arguments, procedure->data.compound_proc.env);
exp = make_begin(procedure->data.compound_proc.body);
tailcall = true;
continue;
}
return make_error(342, "unknown procedure type");
} // is_application()
} while (tailcall);
fprintf(stderr, "cannot eval unknown expression type\n");
exit(EXIT_FAILURE);
}
Term AtomicTo1(Term t, Term ind)
{
List rl;
Term ret;
Term t1;
Atom ttype;
if(is_compound(t) && CompoundName(t)==A_ALG1)
{
List l;
ttype=A_ALG1;
rl=CopyTerm(CompoundArg2(t));
for(l=rl;l;l=ListTail(l))
SetCompoundArg(ListFirst(l),2,0);
goto cnt;
}
if(is_compound(t) && CompoundName(t)==A_FBRACET)
{
t=alg1_mk_wild(t,&rl,&ind);
ttype=OPR_WILD;
goto cnt;
}
/*
if(is_compound(t) && CompoundName(t)==A_CC)
{
t=cc_particle(t,&rl);
ttype=OPR_FIELD;
goto cnt;
}
*/
if(is_let(t,&rl))
{
ttype=OPR_LET;
goto cnt;
}
if(is_parameter(t) || (is_compound(t) && (CompoundName(t)==A_COS ||
CompoundName(t)==A_SIN)) )
{
rl=NewList();
ttype=OPR_PARAMETER;
goto cnt;
}
if(is_particle(t,&rl))
{
ttype=OPR_FIELD;
goto cnt;
}
if(is_special(t,&rl))
{
ttype=OPR_SPECIAL;
goto cnt;
}
ErrorInfo(301);
printf(" \'%s\' undefined object.\n",AtomValue(t));
FreeAtomic(ind);
longjmp(alg1_jmp_buf,1);
cnt:
ret=MakeCompound(A_MTERM,4);
SetCompoundArg(ret,1,NewInteger(1));
SetCompoundArg(ret,2,NewInteger(1));
t1=0;
if(!is_empty_list(rl))
{
Term ttt;
int skipped;
rl=CopyTerm(rl);
if(is_empty_list(ind))
{
SetCompoundArg(ret,3,AppendFirst(NewList(),MakeCompound2(ttype,rl,t)));
return AppendFirst(NewList(),ret);
}
skipped=must_skip(ListLength(ind),rl);
if(skipped==-1)
{
ErrorInfo(302);
printf(" can not set indices ");
WriteTerm(ind);
printf(" to \'%s\'.\n",AtomValue(t));
FreeAtomic(ind); FreeAtomic(rl);
longjmp(alg1_jmp_buf,1);
}
t1=rl;
ttt=ind;
while(!is_empty_list(rl))
{
if(skipped!=0 && should_skip(skipped,CompoundArg1(ListFirst(rl))))
{ rl=ListTail(rl); continue; }
SetCompoundArg(ListFirst(rl),2,ListFirst(ttt));
rl=ListTail(rl);
ttt=ListTail(ttt);
}
FreeAtomic(ind);
}
if(ttype==OPR_PARAMETER && is_compound(t))
{
Term mmm=MakeCompound(ttype,CompoundArity(t)+2);
SetCompoundArg(mmm,1,t1);
SetCompoundArg(mmm,2,CompoundName(t));
SetCompoundArg(mmm,3,CompoundArg1(t));
if(CompoundArity(t)==2)
{
Term m=ExprTo1(ConsumeCompoundArg(t,2));
m=CompoundArg1(m);
if(ListLength(m)!=1)
{
ErrorInfo(0);
puts("bad expression in sin/cos.");
longjmp(alg1_jmp_buf,1);
}
m=ListFirst(m);
SetCompoundArg(mmm,4,m);
}
SetCompoundArg(ret,3,AppendFirst(NewList(),mmm));
}
else
SetCompoundArg(ret,3,AppendFirst(NewList(),MakeCompound2(ttype,t1,t)));
return AppendFirst(NewList(),ret);
}
object *bs_eval(object *exp, object *env)
{
tailcall:
if (is_empty_list(exp)) {
error("unable to evaluate empty list");
} else if (is_self_evaluating(exp)) {
return exp;
} else if (is_variable(exp)) {
return lookup_variable_value(exp, env);
} else if (is_quoted(exp)) {
return quoted_expression(exp);
} else if (is_assignment(exp)) {
return eval_assignment(exp, env);
} else if (is_definition(exp)) {
return eval_definition(exp, env);
} else if (is_if(exp)) {
if (is_true(bs_eval(if_predicate(exp), env))) {
exp = if_consequent(exp);
} else {
exp = if_alternate(exp);
}
goto tailcall;
} else if (is_lambda(exp)) {
return make_compound_proc(lambda_parameters(exp),
lambda_body(exp),
env);
} else if (is_begin(exp)) {
exp = begin_actions(exp);
if (is_empty_list(exp)) {
error("empty begin block");
}
while (!is_empty_list(cdr(exp))) {
bs_eval(car(exp), env);
exp = cdr(exp);
}
exp = car(exp);
goto tailcall;
} else if (is_cond(exp)) {
exp = cond_to_if(exp);
goto tailcall;
} else if (is_let(exp)) {
exp = let_to_application(exp);
goto tailcall;
} else if (is_and(exp)) {
exp = and_tests(exp);
if (is_empty_list(exp)) {
return get_boolean(1);
}
object *result;
while (!is_empty_list(cdr(exp))) {
result = bs_eval(car(exp), env);
if (is_false(result)) {
return result;
}
exp = cdr(exp);
}
exp = car(exp);
goto tailcall;
} else if (is_or(exp)) {
exp = or_tests(exp);
if (is_empty_list(exp)) {
return get_boolean(0);
}
object *result;
while (!is_empty_list(cdr(exp))) {
result = bs_eval(car(exp), env);
if (is_true(result)) {
return result;
}
exp = cdr(exp);
}
exp = car(exp);
goto tailcall;
} else if (is_application(exp)) {
object *procedure = bs_eval(application_operator(exp), env);
object *parameters = eval_parameters(application_operands(exp), env);
// handle eval specially for tailcall requirement.
if (is_primitive_proc(procedure) &&
procedure->value.primitive_proc == eval_proc) {
exp = eval_expression(parameters);
env = eval_environment(parameters);
goto tailcall;
}
// handle apply specially for tailcall requirement.
if (is_primitive_proc(procedure) &&
procedure->value.primitive_proc == apply_proc) {
procedure = apply_operator(parameters);
parameters = apply_operands(parameters);
}
if (is_primitive_proc(procedure)) {
return (procedure->value.primitive_proc)(parameters);
} else if (is_compound_proc(procedure)) {
env = extend_environment(
procedure->value.compound_proc.parameters,
parameters,
procedure->value.compound_proc.env);
exp = make_begin(procedure->value.compound_proc.body);
goto tailcall;
} else {
error("unable to apply unknown procedure type");
}
} else {
error("unable to evaluate expression");
}
}
static pSlipObject slip_eval(pSlip gd, pSlipObject exp, pSlipEnvironment env)
{
pSlipObject proc;
pSlipObject args;
tailcall:
if (is_self_evaluating(exp) == S_TRUE)
{
return exp;
}
else if (is_variable(exp) == S_TRUE)
{
return lookup_variable_value(gd, exp, env);
}
else if (is_quoted(gd, exp) == S_TRUE)
{
return text_of_quotation(exp);
}
else if (is_assignment(gd, exp) == S_TRUE)
{
return eval_assignment(gd, exp, env);
}
else if (is_definition(gd, exp) == S_TRUE)
{
return eval_definition(gd, exp, env);
}
else if (is_if(gd, exp) == S_TRUE)
{
exp = is_true(gd, slip_eval(gd, if_predicate(exp), env)) == S_TRUE ? if_consequent(exp) : if_alternative(gd, exp);
goto tailcall;
}
else if (is_lambda(gd, exp) == S_TRUE)
{
return s_NewCompoundProc(gd, lambda_parameters(exp), lambda_body(exp), env);
}
else if (is_begin(gd, exp) == S_TRUE)
{
exp = begin_actions(exp);
while (!is_last_exp(gd, exp))
{
slip_eval(gd, first_exp(exp), env);
exp = rest_exps(exp);
}
exp = first_exp(exp);
goto tailcall;
}
else if (is_cond(gd, exp) == S_TRUE)
{
exp = cond_to_if(gd, exp);
goto tailcall;
}
else if (is_let(gd, exp) == S_TRUE)
{
exp = let_to_application(gd, exp);
goto tailcall;
}
else if (is_application(exp) == S_TRUE)
{
proc = slip_eval(gd, slip_operator(exp), env);
if (proc == NULL)
return gd->singleton_False;
if (proc->type == eType_PRIMITIVE_PROC || proc->type == eType_COMPOUND_PROC)
{
args = list_of_values(gd, operands(exp), env);
if (args == NULL)
return gd->singleton_False;
if (sIsObject_PrimitiveProc(proc) == S_TRUE)
{
return proc->data.prim_proc.func(gd, args);
}
else if (sIsObject_CompoundProc(proc) == S_TRUE)
{
env = setup_environment(gd, proc->data.comp_proc.env, proc->data.comp_proc.params, args);
exp = make_begin(gd, proc->data.comp_proc.code);
goto tailcall;
}
else
{
throw_error(gd, "unknown procedure type\n");
return gd->singleton_False;
}
}
else
return proc;
}
else
{
throw_error(gd, "cannot eval unknown expression type\n");
return NULL;
}
throw_error(gd, "what??\n");
return NULL;
}
///////////////////////////////////////////////////////////////////
//eval
//requires two arguments:exp & tail_context
///////////////////////////////////////////////////////////////////
cellpoint eval(void)
{
if (is_true(is_self_evaluating(args_ref(1)))){
reg = args_ref(1);
}else if (is_true(is_variable(args_ref(1)))){
reg = args_ref(1);
args_push(current_env);
args_push(reg);
reg = lookup_var_val();
}else if (is_true(is_quoted(args_ref(1)))){
args_push(args_ref(1));
reg = quotation_text();
}else if (is_true(is_assignment(args_ref(1)))){
args_push(args_ref(1));
reg = eval_assignment();
}else if (is_true(is_definition(args_ref(1)))){
args_push(args_ref(1));
reg = eval_definition();
}else if (is_true(is_if(args_ref(1)))){
//eval if expression with the second argument (tail_context)
reg = args_ref(1);
args_push(args_ref(2));
args_push(reg);
reg = eval_if();
}else if (is_true(is_lambda(args_ref(1)))){
args_push(args_ref(1));
reg = eval_lambda();
}else if (is_true(is_begin(args_ref(1)))){
args_push(args_ref(1));
reg = begin_actions();
//eval the actions of begin exp with the second argument (tail_context)
args_push(args_ref(2));
args_push(reg);
reg = eval_sequence();
}else if (is_true(is_cond(args_ref(1)))){
args_push(args_ref(1));
reg = cond_2_if();
//eval the exp with the second argument (tail_context)
args_push(args_ref(2));
args_push(reg);
reg = eval();
}else if (is_true(is_and(args_ref(1)))){
reg = args_ref(1);
args_push(args_ref(2));
args_push(reg);
reg = eval_and();
}else if (is_true(is_or(args_ref(1)))){
reg = args_ref(1);
args_push(args_ref(2));
args_push(reg);
reg = eval_or();
}else if (is_true(is_let(args_ref(1)))){
//convert let to combination
args_push(args_ref(1));
reg = let_2_combination();
//evals the combination
args_push(args_ref(2));
args_push(reg);
reg = eval();
}else if (is_true(is_letstar(args_ref(1)))){
//convert let* to nested lets
args_push(args_ref(1));
reg = letstar_2_nested_lets();
//evals the nested lets
args_push(args_ref(2));
args_push(reg);
reg = eval();
}else if (is_true(is_application(args_ref(1)))){
//computes operator
args_push(args_ref(1));
reg = operator();
args_push(a_false);
args_push(reg);
reg = eval();
stack_push(&vars_stack, reg);
//computes operands
args_push(args_ref(1));
reg = operands();
args_push(reg);
reg = list_of_values();
//calls apply with the second argument (tail_context)
args_push(args_ref(2));
args_push(reg);
args_push(stack_pop(&vars_stack));
reg = apply();
}else {
printf("Unknown expression type -- EVAL\n");
error_handler();
}
args_pop(2);
return reg;
}
