lean4-htt/src/library/tactic/eval.cpp

75 lines
2.9 KiB
C++

/*
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include "util/fresh_name.h"
#include "kernel/type_checker.h"
#include "kernel/kernel_exception.h"
#include "kernel/error_msgs.h"
#include "library/vm/vm.h"
#include "library/vm/vm_expr.h"
#include "library/compiler/vm_compiler.h"
#include "library/tactic/tactic_state.h"
namespace lean {
static vm_obj eval(expr const & A, expr a, tactic_state const & s) {
LEAN_TACTIC_TRY;
metavar_context mctx = s.mctx();
a = mctx.instantiate_mvars(a);
if (has_local(a) || !closed(a))
return tactic::mk_exception("invalid eval_expr, expression must be closed", s);
if (is_constant(a)) {
type_context ctx = mk_type_context_for(s);
if (!ctx.is_def_eq(A, ctx.infer(a)))
return tactic::mk_exception("invalid eval_expr, type mismatch", s);
vm_obj r = get_vm_state().get_constant(const_name(a));
return tactic::mk_success(r, s);
} else {
vm_state & S = get_vm_state();
environment aux_env = S.env();
name eval_aux_name = mk_tagged_fresh_name("_eval_expr");
try {
auto cd = check(aux_env, mk_definition(aux_env, eval_aux_name, {}, A, a, true, false));
aux_env = aux_env.add(cd);
} catch (definition_type_mismatch_exception & ex) {
expr given_type = ex.get_given_type();
return tactic::mk_exception([=]() {
io_state_stream ios = tout();
formatter fmt = ios.get_formatter();
format expected_fmt, given_fmt;
std::tie(expected_fmt, given_fmt) = pp_until_different(fmt, A, given_type);
return format("type error at eval_expr, argument has type '") + given_fmt +
compose(line(), format("but is expected to have type")) +
expected_fmt;
}, s);
} catch (kernel_exception & ex) {
/* We use nested_exception_without_pos to make sure old position information nested in 'a' is not used
in type error messages. */
return tactic::mk_exception(nested_exception_without_pos("eval_expr failed", ex), s);
}
try {
aux_env = vm_compile(aux_env, aux_env.get(eval_aux_name));
} catch (exception & ex) {
return tactic::mk_exception(nested_exception_without_pos("eval_expr failed to compile given expression into bytecode", ex), s);
}
S.update_env(aux_env);
vm_obj r = S.get_constant(eval_aux_name);
return tactic::mk_success(r, s);
}
LEAN_TACTIC_CATCH(s);
}
static vm_obj tactic_eval_expr(vm_obj const &, vm_obj const & A, vm_obj const & a, vm_obj const & s) {
return eval(to_expr(A), to_expr(a), tactic::to_state(s));
}
void initialize_eval() {
DECLARE_VM_BUILTIN(name({"tactic", "eval_expr"}), tactic_eval_expr);
}
void finalize_eval() {
}
}