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fix(kernel/normalizer): do not apply substitutions in the normalizer

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It is incorrect to apply substitutions during normalization.
The problem is that we do not have support for tracking justifications in the normalizer. So, substitutions were being silently applied during normalization. Thus, the correctness of the conflict resolution in the elaboration was being affected.

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2013-10-29 02:11:06 -07:00
parent 7944db2f18
commit 2c6d4d2225
6 changed files with 78 additions and 73 deletions
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35
src/kernel/normalizer.cpp
View file

@ -71,8 +71,6 @@ class normalizer::imp {
environment const & m_env;
context m_ctx;
metavar_env const * m_menv;
unsigned m_menv_timestamp;
cache m_cache;
unsigned m_max_depth;
unsigned m_depth;
@ -193,11 +191,7 @@ class normalizer::imp {
svalue r;
switch (a.kind()) {
case expr_kind::MetaVar:
if (m_menv && m_menv->is_assigned(a)) {
r = normalize(m_menv->get_subst(a), s, k);
} else {
r = svalue(updt_metavar(a, s, k));
}
r = svalue(updt_metavar(a, s, k));
break;
case expr_kind::Var:
r = lookup(s, var_idx(a));
@ -295,38 +289,21 @@ class normalizer::imp {
}
}
void set_menv(metavar_env const * menv) {
if (m_menv == menv) {
// Check whether m_menv has been updated since the last time the normalizer has been invoked
if (m_menv && m_menv->get_timestamp() > m_menv_timestamp) {
m_menv_timestamp = m_menv->get_timestamp();
m_cache.clear();
}
} else {
m_menv = menv;
m_cache.clear();
m_menv_timestamp = m_menv ? m_menv->get_timestamp() : 0;
}
}
public:
imp(environment const & env, unsigned max_depth):
m_env(env) {
m_interrupted = false;
m_max_depth = max_depth;
m_depth = 0;
m_menv = nullptr;
m_menv_timestamp = 0;
}
expr operator()(expr const & e, context const & ctx, metavar_env const * menv) {
expr operator()(expr const & e, context const & ctx) {
set_ctx(ctx);
set_menv(menv);
unsigned k = m_ctx.size();
return reify(normalize(e, value_stack(), k), k);
}
void clear() { m_ctx = context(); m_cache.clear(); m_menv = nullptr; m_menv_timestamp = 0; }
void clear() { m_ctx = context(); m_cache.clear(); }
void set_interrupt(bool flag) { m_interrupted = flag; }
};
@ -334,12 +311,12 @@ normalizer::normalizer(environment const & env, unsigned max_depth):m_ptr(new im
normalizer::normalizer(environment const & env):normalizer(env, std::numeric_limits<unsigned>::max()) {}
normalizer::normalizer(environment const & env, options const & opts):normalizer(env, get_normalizer_max_depth(opts)) {}
normalizer::~normalizer() {}
expr normalizer::operator()(expr const & e, context const & ctx, metavar_env const * menv) { return (*m_ptr)(e, ctx, menv); }
expr normalizer::operator()(expr const & e, context const & ctx) { return (*m_ptr)(e, ctx); }
void normalizer::clear() { m_ptr->clear(); }
void normalizer::set_interrupt(bool flag) { m_ptr->set_interrupt(flag); }
expr normalize(expr const & e, environment const & env, context const & ctx, metavar_env const * menv) {
return normalizer(env)(e, ctx, menv);
expr normalize(expr const & e, environment const & env, context const & ctx) {
return normalizer(env)(e, ctx);
}
}

5
src/kernel/normalizer.h
View file

@ -13,7 +13,6 @@ Author: Leonardo de Moura
namespace lean {
class environment;
class options;
class metavar_env;
/** \brief Functional object for normalizing expressions */
class normalizer {
class imp;
@ -24,7 +23,7 @@ public:
normalizer(environment const & env, options const & opts);
~normalizer();
expr operator()(expr const & e, context const & ctx = context(), metavar_env const * menv = nullptr);
expr operator()(expr const & e, context const & ctx = context());
void clear();
@ -33,5 +32,5 @@ public:
void reset_interrupt() { set_interrupt(false); }
};
/** \brief Normalize \c e using the environment \c env and context \c ctx */
expr normalize(expr const & e, environment const & env, context const & ctx = context(), metavar_env const * menv = nullptr);
expr normalize(expr const & e, environment const & env, context const & ctx = context());
}

2
src/kernel/type_checker.cpp
View file

@ -32,7 +32,7 @@ class type_checker::imp {
volatile bool m_interrupted;
expr normalize(expr const & e, context const & ctx) {
return m_normalizer(e, ctx, m_menv);
return m_normalizer(e, ctx);
}
expr lookup(context const & c, unsigned i) {

2
src/library/elaborator/elaborator.cpp
View file

@ -504,7 +504,7 @@ class elaborator::imp {
}
expr normalize(context const & ctx, expr const & a) {
return m_normalizer(a, ctx, &(m_state.m_menv));
return m_normalizer(a, ctx);
}
void process_app(context const & ctx, expr & a) {

2
src/library/type_inferer.cpp
View file

@ -32,7 +32,7 @@ class type_inferer::imp {
volatile bool m_interrupted;
expr normalize(expr const & e, context const & ctx) {
return m_normalizer(e, ctx, m_menv);
return m_normalizer(e, ctx);
}
expr check_type(expr const & e, expr const & s, context const & ctx) {

105
tests/lean/elab1.lean.expected.out
View file

@ -138,9 +138,9 @@ A : Type, B : Type, a : ?M3::0, b : ?M3::1, C : Type ⊢ ?M3::0[lift:0:3] ≺ C
Error (line: 20, pos: 28) unexpected metavariable occurrence
Failed to solve
⊢ b ≈ a
Destruct/Decompose
⊢ b = b ≺ a = ?M3::3
Normalize
Substitution
⊢ b ≈ ?M3::2
Destruct/Decompose
⊢ b = b ≺ ?M3::2 = ?M3::3
(line: 22: pos: 22) Type of argument 6 must be convertible to the expected type in the application of
Trans::explicit
@ -151,6 +151,19 @@ Failed to solve
?M3::3
Refl a
Refl b
Assignment
⊢ a ≈ ?M3::2
Destruct/Decompose
⊢ a = a ≺ ?M3::1 = ?M3::2
(line: 22: pos: 22) Type of argument 5 must be convertible to the expected type in the application of
Trans::explicit
with arguments:
?M3::0
?M3::1
?M3::2
?M3::3
Refl a
Refl b
Failed to solve
⊢ (?M3::0 ≈ Type) ⊕ (?M3::0 ≈ Type 1) ⊕ (?M3::0 ≈ Type 2) ⊕ (?M3::0 ≈ Type M) ⊕ (?M3::0 ≈ Type U)
Destruct/Decompose
@ -560,51 +573,67 @@ a : Bool, b : Bool, H : ?M3::2, H_na : ?M3::7 ⊢ a ≺ if Bool (if Bool a b ⊤
a : Bool, b : Bool, H : ?M3::2, H_na : ?M3::7 ⊢ a ≈ ?M3::8
Destruct/Decompose
a : Bool, b : Bool, H : ?M3::2, H_na : ?M3::7 ⊢ if Bool a b ⊤ ≈ if Bool ?M3::8 ?M3::9 ⊤
Destruct/Decompose
a : Bool,
b : Bool,
H : ?M3::2,
H_na : ?M3::7 ⊢
if Bool (if Bool a b ⊤) a ⊤ ≺ if Bool (if Bool ?M3::8 ?M3::9 ⊤) ?M3::11 ⊤
Normalize
a : Bool,
b : Bool,
H : ?M3::2,
H_na : ?M3::7 ⊢
(a ⇒ b) ⇒ a ≺ if Bool ?M3::10 ?M3::11 ⊤
Substitution
Normalize
a : Bool, b : Bool, H : ?M3::2, H_na : ?M3::7 ⊢ if Bool a b ⊤ ≈ ?M3::8 ⇒ ?M3::9
Substitution
a : Bool, b : Bool, H : ?M3::2, H_na : ?M3::7 ⊢ if Bool a b ⊤ ≈ ?M3::10
Destruct/Decompose
a : Bool,
b : Bool,
H : ?M3::2,
H_na : ?M3::7 ⊢
?M3::2[lift:0:2] ≺ if Bool ?M3::10 ?M3::11 ⊤
if Bool (if Bool a b ⊤) a ⊤ ≺ if Bool ?M3::10 ?M3::11 ⊤
Normalize
a : Bool,
b : Bool,
H : ?M3::2,
H_na : ?M3::7 ⊢
?M3::2[lift:0:2] ≺ ?M3::10 ⇒ ?M3::11
(line: 29: pos: 48) Type of argument 3 must be convertible to the expected type in the application of
MT::explicit
(a ⇒ b) ⇒ a ≺ if Bool ?M3::10 ?M3::11 ⊤
Substitution
a : Bool,
b : Bool,
H : ?M3::2,
H_na : ?M3::7 ⊢
?M3::2[lift:0:2] ≺ if Bool ?M3::10 ?M3::11 ⊤
Normalize
a : Bool,
b : Bool,
H : ?M3::2,
H_na : ?M3::7 ⊢
?M3::2[lift:0:2] ≺ ?M3::10 ⇒ ?M3::11
(line: 29: pos: 48) Type of argument 3 must be convertible to the expected type in the application of
MT::explicit
with arguments:
?M3::10
?M3::11
H
H_na
Assignment
a : Bool, b : Bool ⊢ ?M3::2 ≈ ?M3::0
Destruct/Decompose
a : Bool,
b : Bool ⊢
Π H : ?M3::2, ?M3::5 ≺ Π _ : ?M3::0, ?M3::1[lift:0:1]
(line: 27: pos: 4) Type of argument 3 must be convertible to the expected type in the application of
Discharge::explicit
with arguments:
?M3::0
?M3::1
λ H : ?M3::2,
DisjCases
(EM a)
(λ H_a : ?M3::6, H)
(λ H_na : ?M3::7, NotImp1 (MT H H_na))
Assignment
a : Bool, b : Bool, H : ?M3::2, H_na : ?M3::7 ⊢ ?M3::10 ≈ ?M3::8 ⇒ ?M3::9
Destruct/Decompose
a : Bool, b : Bool, H : ?M3::2, H_na : ?M3::7 ⊢ ¬ ?M3::10 ≺ ¬ (?M3::8 ⇒ ?M3::9)
(line: 29: pos: 40) Type of argument 3 must be convertible to the expected type in the application of
NotImp1::explicit
with arguments:
?M3::10
?M3::11
H
H_na
Assignment
a : Bool, b : Bool ⊢ ?M3::2 ≈ ?M3::0
Destruct/Decompose
a : Bool, b : Bool ⊢ Π H : ?M3::2, ?M3::5 ≺ Π _ : ?M3::0, ?M3::1[lift:0:1]
(line: 27: pos: 4) Type of argument 3 must be convertible to the expected type in the application of
Discharge::explicit
with arguments:
?M3::0
?M3::1
λ H : ?M3::2,
DisjCases
(EM a)
(λ H_a : ?M3::6, H)
(λ H_na : ?M3::7, NotImp1 (MT H H_na))
?M3::8
?M3::9
MT H H_na
Assignment
a : Bool, b : Bool, H : ?M3::2 ⊢ if Bool (if Bool a b ⊤) a ⊤ ≺ ?M3::5
Normalize