perf(frontends/lean/elaborator): improve performance of pi_abstract_context

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2014-07-12 17:49:14 +01:00
parent 03bbec08e5
commit cb93d194ed

View file

@ -136,6 +136,8 @@ class elaborator {
expr_map<expr> m_cache; // (pointer equality) cache for Type and Constants (this is a trick to make sure we get the
// same universe metavariable for different occurrences of the same Type/Constant
context m_ctx; // current local context: a list of local constants
buffer<expr> m_ctx_buffer; // m_ctx as a buffer
buffer<expr> m_ctx_domain_buffer; // m_ctx_domain_buffer[i] == abstract_locals(m_ctx_buffer[i], i, m_ctx_buffer.begin())
pos_info_provider * m_pos_provider; // optional expression position information used when reporting errors.
justification m_accumulated; // accumulate justification of eagerly used substitutions
constraint_vect m_constraints; // constraints that must be solved for the elaborated term to be type correct.
@ -147,6 +149,35 @@ class elaborator {
bool m_check_unassigned; // if true if display error messages if elaborated term still contains metavariables
bool m_use_local_instances; // if true class-instance resolution will use the local context
// Set m_ctx to ctx, and make sure m_ctx_buffer and m_ctx_domain_buffer reflect the contents of the new ctx
void set_ctx(context const & ctx) {
m_ctx = ctx;
m_ctx_buffer.clear();
m_ctx_domain_buffer.clear();
to_buffer(ctx, m_ctx_buffer);
std::reverse(m_ctx_buffer.begin(), m_ctx_buffer.end());
for (unsigned i = 0; i < m_ctx_buffer.size(); i++) {
m_ctx_domain_buffer.push_back(abstract_locals(m_ctx_buffer[i], i, m_ctx_buffer.data()));
}
}
// "Scoped update": add an local constant l to the m_ctx (and m_ctx_buffer, m_ctx_domain_buffer).
// "Undoes" the changes in the end of the scope where this object was defined.
struct update_ctx {
elaborator & m_main;
update_ctx(elaborator & main, expr const & l):m_main(main) {
lean_assert(is_local(l));
m_main.m_ctx = cons(l, m_main.m_ctx);
m_main.m_ctx_domain_buffer.push_back(abstract_locals(l, m_main.m_ctx_buffer.size(), m_main.m_ctx_buffer.data()));
m_main.m_ctx_buffer.push_back(l);
}
~update_ctx() {
m_main.m_ctx = tail(m_main.m_ctx);
m_main.m_ctx_domain_buffer.pop_back();
m_main.m_ctx_buffer.pop_back();
}
};
/** \brief Auxiliary object for creating backtracking points.
\remark A scope can only be created when m_constraints and m_subst are empty,
and m_accumulated is none.
@ -158,12 +189,12 @@ class elaborator {
lean_assert(m_main.m_constraints.empty());
lean_assert(m_main.m_accumulated.is_none());
m_old_ctx = m_main.m_ctx;
m_main.m_ctx = ctx;
m_main.set_ctx(ctx);
m_main.m_tc->push();
m_main.m_subst = s;
}
~scope() {
m_main.m_ctx = m_old_ctx;
m_main.set_ctx(m_old_ctx);
m_main.m_tc->pop();
m_main.m_constraints.clear();
m_main.m_accumulated = justification();
@ -372,19 +403,24 @@ public:
return e;
}
expr mk_app(expr const & f, expr const & a, tag g) {
return save_tag(::lean::mk_app(f, a), g);
}
/** \brief Given <tt>e[l_1, ..., l_n]</tt> and assuming \c m_ctx is
<tt>[l_n : A_n[l_1, ..., l_{n-1}], ..., l_1 : A_1 ]</tt>,
then the result is
<tt>(Pi (x_1 : A_1) ... (x_n : A_n[x_1, ..., x_{n-1}]), e[x_1, ... x_n])</tt>.
*/
expr pi_abstract_context(expr e, tag g) {
for (auto const & p : m_ctx)
e = save_tag(Pi(p, e), g);
return e;
e = abstract_locals(e, m_ctx_buffer.size(), m_ctx_buffer.data());
unsigned i = m_ctx_domain_buffer.size();
while (i > 0) {
--i;
expr const & l = m_ctx_domain_buffer[i];
e = save_tag(mk_pi(local_pp_name(l), mlocal_type(l), e, local_info(l)), g);
}
expr mk_app(expr const & f, expr const & a, tag g) {
return save_tag(::lean::mk_app(f, a), g);
return e;
}
/** \brief Assuming \c m_ctx is
@ -392,15 +428,9 @@ public:
return <tt>(f l_1 ... l_n)</tt>.
*/
expr apply_context(expr const & f, tag g) {
buffer<expr> args;
for (auto const & p : m_ctx)
args.push_back(p);
expr r = f;
unsigned i = args.size();
while (i > 0) {
--i;
r = mk_app(r, args[i], g);
}
for (unsigned i = 0; i < m_ctx_buffer.size(); i++)
r = mk_app(r, m_ctx_buffer[i], g);
return r;
}
@ -780,7 +810,7 @@ public:
expr l = mk_local(binding_name(e), d, binding_info(e));
expr b = instantiate(binding_body(e), l);
if (binding_info(e).is_contextual()) {
flet<context> set(m_ctx, cons(l, m_ctx));
update_ctx add(*this, l);
b = ensure_type(visit_expecting_type(b));
} else {
b = ensure_type(visit_expecting_type(b));
@ -794,7 +824,7 @@ public:
expr l = mk_local(binding_name(e), d, binding_info(e));
expr b = instantiate(binding_body(e), l);
if (binding_info(e).is_contextual()) {
flet<context> set(m_ctx, cons(l, m_ctx));
update_ctx add(*this, l);
b = visit(b);
} else {
b = visit(b);