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refactor(kernel/free_vars): replace max_free_var with relaxed free_var_range

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Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
This commit is contained in:
Leonardo de Moura 2014-01-12 17:06:57 -08:00
parent 582569b793
commit 5d9a95addd
2 changed files with 13 additions and 27 deletions
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33
src/kernel/free_vars.cpp
View file

@ -5,6 +5,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura Author: Leonardo de Moura
*/ */
#include <algorithm> #include <algorithm>
#include <limits>
#include "kernel/free_vars.h" #include "kernel/free_vars.h"
#include "kernel/expr_sets.h" #include "kernel/expr_sets.h"
#include "kernel/replace_fn.h" #include "kernel/replace_fn.h"
@ -113,7 +114,7 @@ bool has_free_vars(expr const & e) {
*/ */
class free_var_range_fn { class free_var_range_fn {
expr_map<unsigned> m_cached; expr_map<unsigned> m_cached;
metavar_env const & m_menv; optional<metavar_env> const & m_menv;
static unsigned dec(unsigned s) { return (s == 0) ? 0 : s - 1; } static unsigned dec(unsigned s) { return (s == 0) ? 0 : s - 1; }
@ -129,7 +130,9 @@ class free_var_range_fn {
*/ */
unsigned process_metavar(expr const & m) { unsigned process_metavar(expr const & m) {
lean_assert(is_metavar(m)); lean_assert(is_metavar(m));
context ctx = m_menv->get_context(metavar_name(m)); if (!m_menv)
return std::numeric_limits<unsigned>::max(); // metavariable environment is not available, assume the worst.
context ctx = (*m_menv)->get_context(metavar_name(m));
unsigned R = ctx.size(); unsigned R = ctx.size();
if (has_local_context(m)) { if (has_local_context(m)) {
local_context lctx = metavar_lctx(m); local_context lctx = metavar_lctx(m);
@ -218,12 +221,16 @@ class free_var_range_fn {
return result; return result;
} }
public: public:
free_var_range_fn(metavar_env const & menv):m_menv(menv) {} free_var_range_fn(optional<metavar_env> const & menv):m_menv(menv) {}
unsigned operator()(expr const & e) { return apply(e); } unsigned operator()(expr const & e) { return apply(e); }
}; };
unsigned free_var_range(expr const & e, metavar_env const & menv) { unsigned free_var_range(expr const & e, metavar_env const & menv) {
return free_var_range_fn(menv)(e); return free_var_range_fn(some_menv(menv))(e);
}
unsigned free_var_range(expr const & e) {
return free_var_range_fn(none_menv())(e);
} }
/** /**
@ -322,7 +329,7 @@ public:
m_high(high) { m_high(high) {
lean_assert(low < high); lean_assert(low < high);
if (menv) if (menv)
m_range_fn.reset(new free_var_range_fn(*menv)); m_range_fn.reset(new free_var_range_fn(menv));
} }
bool operator()(expr const & e) { return apply(e, 0); } bool operator()(expr const & e) { return apply(e, 0); }
}; };
@ -398,20 +405,4 @@ context_entry lift_free_vars(context_entry const & e, unsigned s, unsigned d, me
else else
return context_entry(e.get_name(), none_expr(), lift_free_vars(*body, s, d, menv)); return context_entry(e.get_name(), none_expr(), lift_free_vars(*body, s, d, menv));
} }
optional<unsigned> max_free_var(expr const & e) {
optional<unsigned> r;
for_each(e, [&](expr const & v, unsigned offset) {
if (is_var(v)) {
unsigned vidx = var_idx(v);
if (vidx >= offset) {
vidx -= offset;
if (!r || vidx > *r)
r = vidx;
}
}
return true;
});
return r;
}
} }

7
src/kernel/free_vars.h
View file

@ -36,6 +36,7 @@ class metavar_env;
[lift:s:n] R ===> if s >= R then R else R + n [lift:s:n] R ===> if s >= R then R else R + n
*/ */
unsigned free_var_range(expr const & e, metavar_env const & menv); unsigned free_var_range(expr const & e, metavar_env const & menv);
unsigned free_var_range(expr const & e);
/** /**
\brief Return true iff \c e constains a free variable <tt>(var i)</tt> s.t. \c i in <tt>[low, high)</tt>. \brief Return true iff \c e constains a free variable <tt>(var i)</tt> s.t. \c i in <tt>[low, high)</tt>.
@ -88,10 +89,4 @@ expr lift_free_vars(expr const & e, unsigned d, metavar_env const & menv);
expr lift_free_vars(expr const & e, unsigned d); expr lift_free_vars(expr const & e, unsigned d);
context_entry lift_free_vars(context_entry const & e, unsigned s, unsigned d, metavar_env const & menv); context_entry lift_free_vars(context_entry const & e, unsigned s, unsigned d, metavar_env const & menv);
/**
\brief Return the index of the max free var occurring in \c e.
Return none if \c e does not contain free variables.
*/
optional<unsigned> max_free_var(expr const & e);
} }