feat(frontends/lean/elaborator): add "noncomputable theory" command, display "noncomputable" when printing definitions

When the command "noncomputable theory" is used, Lean will not sign an
error when a noncomputable definition is not marked as noncomputable
This commit is contained in:
Leonardo de Moura 2015-07-29 17:54:35 -07:00
parent 384ccf2b6c
commit be61fb0566
12 changed files with 86 additions and 34 deletions

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@ -3,4 +3,4 @@ Copyright (c) 2014 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Robert Y. Lewis
-/
import .basic .order
import .basic .order .division .complete

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@ -678,4 +678,6 @@ section migrate_algebra
divide → divide, max → max, min → min
end migrate_algebra
infix / := divide
end real

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@ -10,7 +10,7 @@
(defconst lean-keywords
'("import" "prelude" "tactic_hint" "protected" "private" "noncomputable" "definition" "renaming"
"hiding" "exposing" "parameter" "parameters" "begin" "begin+" "proof" "qed" "conjecture" "constant" "constants"
"hypothesis" "lemma" "corollary" "variable" "variables" "premise" "premises"
"hypothesis" "lemma" "corollary" "variable" "variables" "premise" "premises" "theory"
"print" "theorem" "example" "abbreviation" "abstract"
"open" "as" "export" "override" "axiom" "axioms" "inductive" "with" "structure" "record" "universe" "universes"
"alias" "help" "environment" "options" "precedence" "reserve"

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@ -25,6 +25,7 @@ Author: Leonardo de Moura
#include "library/reducible.h"
#include "library/normalize.h"
#include "library/print.h"
#include "library/noncomputable.h"
#include "library/class.h"
#include "library/flycheck.h"
#include "library/abbreviation.h"
@ -313,6 +314,8 @@ static void print_recursor_info(parser & p) {
bool print_constant(parser & p, char const * kind, declaration const & d, bool is_def = false) {
io_state_stream out = p.regular_stream();
if (d.is_definition() && is_marked_noncomputable(p.env(), d.get_name()))
out << "noncomputable ";
if (is_protected(p.env(), d.get_name()))
out << "protected ";
out << kind << " " << d.get_name();

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@ -866,6 +866,7 @@ class definition_cmd_fn {
void register_decl(name const & n, name const & real_n, expr const & type) {
if (m_kind != Example) {
if (!m_p.ignore_noncomputable()) {
if (!m_is_noncomputable && is_marked_noncomputable(m_env, real_n)) {
auto reason = get_noncomputable_reason(m_env, real_n);
lean_assert(reason);
@ -880,6 +881,7 @@ class definition_cmd_fn {
if (m_is_noncomputable && !is_marked_noncomputable(m_env, real_n)) {
throw exception(sstream() << "definition '" << n << "' was incorrectly marked as noncomputable");
}
}
// TODO(Leo): register aux_decls
if (!m_is_private)
m_p.add_decl_index(real_n, m_pos, m_p.get_cmd_token(), type);
@ -1176,6 +1178,11 @@ static environment protected_definition_cmd(parser & p) {
}
}
static environment noncomputable_cmd(parser & p) {
if (p.curr_is_token_or_id(get_theory_tk())) {
p.next();
p.set_ignore_noncomputable();
return p.env();
} else {
bool is_private = false;
bool is_protected = false;
if (p.curr_is_token(get_private_tk())) {
@ -1199,6 +1206,7 @@ static environment noncomputable_cmd(parser & p) {
}
return definition_cmd_core(p, kind, is_private, is_protected, true);
}
}
static environment include_cmd_core(parser & p, bool include) {
if (!p.curr_is_identifier())

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@ -126,6 +126,7 @@ parser::parser(environment const & env, io_state const & ios,
m_snapshot_vector(sv), m_info_manager(im), m_cache(nullptr), m_index(nullptr) {
m_local_decls_size_at_beg_cmd = 0;
m_in_backtick = false;
m_ignore_noncomputable = false;
m_profile = ios.get_options().get_bool("profile", false);
init_stop_at(ios.get_options());
if (num_threads > 1 && m_profile)
@ -1942,7 +1943,7 @@ void parser::add_delayed_theorem(certified_declaration const & cd) {
void parser::replace_theorem(certified_declaration const & thm) {
m_env = m_env.replace(thm);
name const & thm_name = thm.get_declaration().get_name();
if (!check_computable(m_env, thm_name)) {
if (!m_ignore_noncomputable && !check_computable(m_env, thm_name)) {
throw exception(sstream() << "declaration '" << thm_name
<< "' was marked as a theorem, but it is a noncomputable definition");
}

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@ -151,6 +151,10 @@ class parser {
bool m_stop_at; // if true, then parser stops execution after the given line and column is reached
unsigned m_stop_at_line;
// If the following flag is true we do not raise error messages
// noncomputable definitions not tagged as noncomputable.
bool m_ignore_noncomputable;
void display_warning_pos(unsigned line, unsigned pos);
void display_error_pos(unsigned line, unsigned pos);
void display_error_pos(pos_info p);
@ -264,6 +268,9 @@ public:
info_manager * im = nullptr, keep_theorem_mode tmode = keep_theorem_mode::All);
~parser();
bool ignore_noncomputable() const { return m_ignore_noncomputable; }
void set_ignore_noncomputable() { m_ignore_noncomputable = true; }
unsigned curr_expr_lbp() const { return curr_lbp_core(false); }
unsigned curr_tactic_lbp() const { return curr_lbp_core(true); }

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@ -153,6 +153,7 @@ static name const * g_metaclasses_tk = nullptr;
static name const * g_inductive_tk = nullptr;
static name const * g_this_tk = nullptr;
static name const * g_noncomputable_tk = nullptr;
static name const * g_theory_tk = nullptr;
void initialize_tokens() {
g_period_tk = new name{"."};
g_placeholder_tk = new name{"_"};
@ -304,6 +305,7 @@ void initialize_tokens() {
g_inductive_tk = new name{"inductive"};
g_this_tk = new name{"this"};
g_noncomputable_tk = new name{"noncomputable"};
g_theory_tk = new name{"theory"};
}
void finalize_tokens() {
delete g_period_tk;
@ -456,6 +458,7 @@ void finalize_tokens() {
delete g_inductive_tk;
delete g_this_tk;
delete g_noncomputable_tk;
delete g_theory_tk;
}
name const & get_period_tk() { return *g_period_tk; }
name const & get_placeholder_tk() { return *g_placeholder_tk; }
@ -607,4 +610,5 @@ name const & get_metaclasses_tk() { return *g_metaclasses_tk; }
name const & get_inductive_tk() { return *g_inductive_tk; }
name const & get_this_tk() { return *g_this_tk; }
name const & get_noncomputable_tk() { return *g_noncomputable_tk; }
name const & get_theory_tk() { return *g_theory_tk; }
}

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@ -155,4 +155,5 @@ name const & get_metaclasses_tk();
name const & get_inductive_tk();
name const & get_this_tk();
name const & get_noncomputable_tk();
name const & get_theory_tk();
}

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@ -148,3 +148,4 @@ metaclasses metaclasses
inductive inductive
this this
noncomputable noncomputable
theory theory

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@ -0,0 +1,20 @@
import data.real
open real
definition f (a b : real) := (a + a) / b -- ERROR f is noncomputable
noncomputable definition f (a b : real) := (a + a) / b -- ERROR f is noncomputable
noncomputable theory
definition g (a b : real) := (a + a) / b
definition h (a b : real) := (a - a) / b
definition f₂ (a b : real) := (a * a) / b
definition r (a : nat) := a
print g -- g is still marked as noncomputable
print r

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@ -0,0 +1,5 @@
noncomp_theory.lean:4:0: error: definition 'f' is noncomputable, it depends on 'real.divide'
noncomputable definition g : :=
λ (a : ), divide (a + a)
definition r : :=
λ (a : ), a