From db31cc37a1bd5af8bd7d90318b283551f7b7453c Mon Sep 17 00:00:00 2001 From: Leonardo de Moura Date: Sun, 16 Feb 2014 13:36:46 -0800 Subject: [PATCH] refactor(kernel/free_vars): cleanup free_vars procedures Signed-off-by: Leonardo de Moura --- src/kernel/CMakeLists.txt | 4 +- src/kernel/free_vars.cpp | 244 ++++++++------------------------------ src/kernel/free_vars.h | 68 +---------- 3 files changed, 55 insertions(+), 261 deletions(-) diff --git a/src/kernel/CMakeLists.txt b/src/kernel/CMakeLists.txt index b220ecf1e..12fdb56a7 100644 --- a/src/kernel/CMakeLists.txt +++ b/src/kernel/CMakeLists.txt @@ -1,6 +1,6 @@ add_library(kernel level.cpp diff_cnstrs.cpp expr.cpp expr_eq_fn.cpp -for_each_fn.cpp occurs.cpp replace_fn.cpp -# free_vars.cpp abstract.cpp instantiate.cpp +for_each_fn.cpp occurs.cpp replace_fn.cpp free_vars.cpp +# abstract.cpp instantiate.cpp # normalizer.cpp context.cpp level.cpp object.cpp environment.cpp # type_checker.cpp kernel.cpp occurs.cpp metavar.cpp # justification.cpp unification_constraint.cpp kernel_exception.cpp diff --git a/src/kernel/free_vars.cpp b/src/kernel/free_vars.cpp index 265376adf..19ba801c0 100644 --- a/src/kernel/free_vars.cpp +++ b/src/kernel/free_vars.cpp @@ -10,7 +10,6 @@ Author: Leonardo de Moura #include "kernel/expr_sets.h" #include "kernel/replace_fn.h" #include "kernel/for_each_fn.h" -#include "kernel/metavar.h" namespace lean { /** @@ -30,19 +29,14 @@ protected: bool apply(expr const & e, unsigned offset) { // handle easy cases switch (e.kind()) { - case expr_kind::Constant: - if (!const_type(e)) - return false; - break; - case expr_kind::Type: case expr_kind::Value: + case expr_kind::Constant: case expr_kind::Sort: case expr_kind::Macro: return false; - case expr_kind::MetaVar: - return true; case expr_kind::Var: return var_idx(e) >= offset; - case expr_kind::App: case expr_kind::Lambda: - case expr_kind::Pi: case expr_kind::Let: case expr_kind::Sigma: - case expr_kind::Proj: case expr_kind::Pair: case expr_kind::HEq: + case expr_kind::App: case expr_kind::Let: + case expr_kind::Meta: case expr_kind::Local: + case expr_kind::Lambda: case expr_kind::Pi: case expr_kind::Sigma: + case expr_kind::Pair: case expr_kind::Fst: case expr_kind::Snd: break; } @@ -70,28 +64,23 @@ protected: bool result = false; switch (e.kind()) { - case expr_kind::Constant: - lean_assert(const_type(e)); - result = apply(const_type(e), offset); - break; - case expr_kind::Type: case expr_kind::Value: case expr_kind::Var: case expr_kind::MetaVar: - // easy cases were already handled + case expr_kind::Constant: case expr_kind::Sort: case expr_kind::Macro: + case expr_kind::Var: lean_unreachable(); // LCOV_EXCL_LINE + case expr_kind::Meta: case expr_kind::Local: + result = apply(mlocal_type(e), offset); case expr_kind::App: - result = std::any_of(begin_args(e), end_args(e), [=](expr const & arg){ return apply(arg, offset); }); + result = apply(app_fn(e), offset) || apply(app_arg(e), offset); + break; + case expr_kind::Fst: case expr_kind::Snd: + result = apply(proj_arg(e), offset); break; case expr_kind::Lambda: case expr_kind::Pi: case expr_kind::Sigma: - result = apply(abst_domain(e), offset) || apply(abst_body(e), offset + 1); + result = apply(binder_domain(e), offset) || apply(binder_body(e), offset + 1); break; case expr_kind::Let: result = apply(let_type(e), offset) || apply(let_value(e), offset) || apply(let_body(e), offset + 1); break; - case expr_kind::HEq: - result = apply(heq_lhs(e), offset) || apply(heq_rhs(e), offset); - break; - case expr_kind::Proj: - result = apply(proj_arg(e), offset); - break; case expr_kind::Pair: result = apply(pair_first(e), offset) || apply(pair_second(e), offset) || apply(pair_type(e), offset); break; @@ -121,47 +110,9 @@ bool has_free_vars(expr const & e) { */ class free_var_range_fn { expr_map m_cached; - optional const & m_menv; static unsigned dec(unsigned s) { return (s == 0) ? 0 : s - 1; } - /* - \brief If a metavariable \c m was defined in a context \c ctx and ctx.size() == R, - then \c m can only contain free variables in the range [0, R) - - So, if \c m does not have an associated local context, the answer is just \c R. - If \c m has an associated local context, we process it using the following rules - - [inst:s v] R ===> if s >= R then R else max(R-1, range_of(v)) - [lift:s:n] R ===> if s >= R then R else R + n - */ - unsigned process_metavar(expr const & m) { - lean_assert(is_metavar(m)); - if (!m_menv) - return std::numeric_limits::max(); // metavariable environment is not available, assume the worst. - context ctx = (*m_menv)->get_context(metavar_name(m)); - unsigned R = ctx.size(); - if (has_local_context(m)) { - local_context lctx = metavar_lctx(m); - buffer lentries; - to_buffer(lctx, lentries); - unsigned i = lentries.size(); - while (i > 0) { - --i; - local_entry const & entry = lentries[i]; - if (entry.is_inst()) { - if (entry.s() < R) { - R = std::max(dec(R), apply(entry.v())); - } - } else { - if (entry.s() < R) - R += entry.n(); - } - } - } - return R; - } - unsigned apply(optional const & e) { return e ? apply(*e) : 0; } @@ -169,19 +120,14 @@ class free_var_range_fn { unsigned apply(expr const & e) { // handle easy cases switch (e.kind()) { - case expr_kind::Constant: - if (!const_type(e)) - return 0; - break; - case expr_kind::Type: case expr_kind::Value: + case expr_kind::Constant: case expr_kind::Sort: case expr_kind::Macro: return 0; case expr_kind::Var: return var_idx(e) + 1; - case expr_kind::MetaVar: case expr_kind::App: - case expr_kind::Lambda: case expr_kind::Pi: - case expr_kind::Let: case expr_kind::Sigma: - case expr_kind::Proj: case expr_kind::Pair: - case expr_kind::HEq: + case expr_kind::App: case expr_kind::Let: + case expr_kind::Meta: case expr_kind::Local: + case expr_kind::Lambda: case expr_kind::Pi: case expr_kind::Sigma: + case expr_kind::Pair: case expr_kind::Fst: case expr_kind::Snd: break; } @@ -199,30 +145,21 @@ class free_var_range_fn { unsigned result = 0; switch (e.kind()) { - case expr_kind::Constant: - lean_assert(const_type(e)); - result = apply(const_type(e)); - break; - case expr_kind::Type: case expr_kind::Value: case expr_kind::Var: - // easy cases were already handled + case expr_kind::Constant: case expr_kind::Sort: case expr_kind::Macro: + case expr_kind::Var: lean_unreachable(); // LCOV_EXCL_LINE - case expr_kind::MetaVar: - result = process_metavar(e); - break; + case expr_kind::Meta: case expr_kind::Local: + result = apply(mlocal_type(e)); case expr_kind::App: - for (auto const & c : args(e)) - result = std::max(result, apply(c)); + result = std::max(apply(app_fn(e)), apply(app_arg(e))); break; case expr_kind::Lambda: case expr_kind::Pi: case expr_kind::Sigma: - result = std::max(apply(abst_domain(e)), dec(apply(abst_body(e)))); + result = std::max(apply(binder_domain(e)), dec(apply(binder_body(e)))); break; case expr_kind::Let: result = std::max({apply(let_type(e)), apply(let_value(e)), dec(apply(let_body(e)))}); break; - case expr_kind::HEq: - result = std::max(apply(heq_lhs(e)), apply(heq_rhs(e))); - break; - case expr_kind::Proj: + case expr_kind::Fst: case expr_kind::Snd: result = apply(proj_arg(e)); break; case expr_kind::Pair: @@ -236,26 +173,16 @@ class free_var_range_fn { return result; } public: - free_var_range_fn(optional const & menv):m_menv(menv) {} + free_var_range_fn() {} unsigned operator()(expr const & e) { return apply(e); } }; -unsigned free_var_range(expr const & e, ro_metavar_env const & menv) { - if (closed(e)) - return 0; - else - return free_var_range_fn(some_ro_menv(menv))(e); -} - unsigned free_var_range(expr const & e) { - return free_var_range_fn(none_ro_menv())(e); + return free_var_range_fn()(e); } /** \brief Functional object for checking whether a kernel expression has a free variable in the range [low, high) or not. - - \remark We assume that a metavariable contains free variables. - This is an approximation, since we don't know how the metavariable will be instantiated. */ class has_free_var_in_range_fn { protected: @@ -292,23 +219,14 @@ protected: bool apply(expr const & e, unsigned offset) { // handle easy cases switch (e.kind()) { - case expr_kind::Constant: - if (!const_type(e)) - return false; - break; - case expr_kind::Type: case expr_kind::Value: + case expr_kind::Constant: case expr_kind::Sort: case expr_kind::Macro: return false; - case expr_kind::MetaVar: - if (m_range_fn) - break; // it is not cheap - else - return true; // assume that any free variable can occur in the metavariable case expr_kind::Var: return in_interval(var_idx(e), offset); - case expr_kind::App: case expr_kind::Lambda: case expr_kind::Pi: - case expr_kind::Let: case expr_kind::Sigma: - case expr_kind::Proj: case expr_kind::Pair: - case expr_kind::HEq: + case expr_kind::App: case expr_kind::Let: + case expr_kind::Meta: case expr_kind::Local: + case expr_kind::Lambda: case expr_kind::Pi: case expr_kind::Sigma: + case expr_kind::Pair: case expr_kind::Fst: case expr_kind::Snd: break; } @@ -326,37 +244,21 @@ protected: bool result = false; switch (e.kind()) { - case expr_kind::Constant: - lean_assert(const_type(e)); - result = apply(const_type(e), offset); - break; - case expr_kind::Type: case expr_kind::Value: case expr_kind::Var: - // easy cases were already handled + case expr_kind::Constant: case expr_kind::Sort: case expr_kind::Macro: + case expr_kind::Var: lean_unreachable(); // LCOV_EXCL_LINE - case expr_kind::MetaVar: { - lean_assert(m_range_fn); - unsigned R = (*m_range_fn)(e); - if (R > 0) { - unsigned max_fvar_idx = R - 1; - result = ge_lower(max_fvar_idx, offset); - // Remark: Variable #0 may occur in \c e. - // So, we don't have to check the upper bound offset + m_high; - } - break; - } + case expr_kind::Meta: case expr_kind::Local: + result = apply(mlocal_type(e), offset); case expr_kind::App: - result = std::any_of(begin_args(e), end_args(e), [=](expr const & arg){ return apply(arg, offset); }); + result = apply(app_fn(e), offset) || apply(app_arg(e), offset); break; case expr_kind::Lambda: case expr_kind::Pi: case expr_kind::Sigma: - result = apply(abst_domain(e), offset) || apply(abst_body(e), offset + 1); + result = apply(binder_domain(e), offset) || apply(binder_body(e), offset + 1); break; case expr_kind::Let: result = apply(let_type(e), offset) || apply(let_value(e), offset) || apply(let_body(e), offset + 1); break; - case expr_kind::HEq: - result = apply(heq_lhs(e), offset) || apply(heq_rhs(e), offset); - break; - case expr_kind::Proj: + case expr_kind::Fst: case expr_kind::Snd: result = apply(proj_arg(e), offset); break; case expr_kind::Pair: @@ -370,46 +272,28 @@ protected: return result; } public: - has_free_var_in_range_fn(unsigned low, unsigned high, optional const & menv): + has_free_var_in_range_fn(unsigned low, unsigned high): m_low(low), m_high(high) { lean_assert(low < high); - if (menv) - m_range_fn.reset(new free_var_range_fn(menv)); } bool operator()(expr const & e) { return apply(e, 0); } }; -bool has_free_var(expr const & e, unsigned low, unsigned high, optional const & menv) { - return high > low && !closed(e) && has_free_var_in_range_fn(low, high, menv)(e); +bool has_free_var(expr const & e, unsigned low, unsigned high) { + return high > low && !closed(e) && has_free_var_in_range_fn(low, high)(e); } -bool has_free_var(expr const & e, unsigned low, unsigned high, ro_metavar_env const & menv) { return has_free_var(e, low, high, some_ro_menv(menv)); } -bool has_free_var(expr const & e, unsigned low, unsigned high) { return has_free_var(e, low, high, none_ro_menv()); } -bool has_free_var(expr const & e, unsigned i, optional const & menv) { return has_free_var(e, i, i+1, menv); } -bool has_free_var(expr const & e, unsigned i, ro_metavar_env const & menv) { return has_free_var(e, i, i+1, menv); } bool has_free_var(expr const & e, unsigned i) { return has_free_var(e, i, i+1); } -bool has_free_var(context_entry const & e, unsigned low, unsigned high, ro_metavar_env const & menv) { - if (high <= low) - return false; - auto d = e.get_domain(); - auto b = e.get_body(); - return (d && has_free_var(*d, low, high, menv)) || (b && has_free_var(*b, low, high, menv)); +bool has_free_var_ge(expr const & e, unsigned low) { + return has_free_var(e, low, std::numeric_limits::max()); } -bool has_free_var_ge(expr const & e, unsigned low, ro_metavar_env const & menv) { - return has_free_var(e, low, std::numeric_limits::max(), menv); -} -bool has_free_var_ge(expr const & e, unsigned low, optional const & menv) { - return has_free_var(e, low, std::numeric_limits::max(), menv); -} -bool has_free_var_ge(expr const & e, unsigned low) { return has_free_var(e, low, std::numeric_limits::max()); } - -expr lower_free_vars(expr const & e, unsigned s, unsigned d, optional const & DEBUG_CODE(menv)) { +expr lower_free_vars(expr const & e, unsigned s, unsigned d) { if (d == 0 || closed(e)) return e; lean_assert(s >= d); - lean_assert(!has_free_var(e, s-d, s, menv)); + lean_assert(!has_free_var(e, s-d, s)); return replace(e, [=](expr const & e, unsigned offset) -> expr { if (is_var(e) && var_idx(e) >= s + offset) { lean_assert(var_idx(e) >= offset + d); @@ -419,50 +303,18 @@ expr lower_free_vars(expr const & e, unsigned s, unsigned d, optional const & menv) { return lower_free_vars(e, d, d, menv); } -expr lower_free_vars(expr const & e, unsigned d, ro_metavar_env const & menv) { return lower_free_vars(e, d, d, menv); } expr lower_free_vars(expr const & e, unsigned d) { return lower_free_vars(e, d, d); } -context_entry lower_free_vars(context_entry const & e, unsigned s, unsigned d, ro_metavar_env const & menv) { - auto domain = e.get_domain(); - auto body = e.get_body(); - if (domain && body) - return context_entry(e.get_name(), lower_free_vars(*domain, s, d, menv), lower_free_vars(*body, s, d, menv)); - else if (domain) - return context_entry(e.get_name(), lower_free_vars(*domain, s, d, menv)); - else - return context_entry(e.get_name(), none_expr(), lower_free_vars(*body, s, d, menv)); -} - -expr lift_free_vars(expr const & e, unsigned s, unsigned d, optional const & menv) { +expr lift_free_vars(expr const & e, unsigned s, unsigned d) { if (d == 0 || closed(e)) return e; return replace(e, [=](expr const & e, unsigned offset) -> expr { if (is_var(e) && var_idx(e) >= s + offset) { return mk_var(var_idx(e) + d); - } else if (is_metavar(e)) { - return add_lift(e, s + offset, d, menv); } else { return e; } }); } -expr lift_free_vars(expr const & e, unsigned s, unsigned d, ro_metavar_env const & menv) { return lift_free_vars(e, s, d, some_ro_menv(menv)); } -expr lift_free_vars(expr const & e, unsigned s, unsigned d) { return lift_free_vars(e, s, d, none_ro_menv()); } -expr lift_free_vars(expr const & e, unsigned d, optional const & menv) { return lift_free_vars(e, 0, d, menv); } expr lift_free_vars(expr const & e, unsigned d) { return lift_free_vars(e, 0, d); } -expr lift_free_vars(expr const & e, unsigned d, ro_metavar_env const & menv) { return lift_free_vars(e, 0, d, menv); } - -context_entry lift_free_vars(context_entry const & e, unsigned s, unsigned d, ro_metavar_env const & menv) { - auto domain = e.get_domain(); - auto body = e.get_body(); - if (domain && body) - return context_entry(e.get_name(), lift_free_vars(*domain, s, d, menv), lift_free_vars(*body, s, d, menv)); - else if (domain) - return context_entry(e.get_name(), lift_free_vars(*domain, s, d, menv)); - else - return context_entry(e.get_name(), none_expr(), lift_free_vars(*body, s, d, menv)); -} } diff --git a/src/kernel/free_vars.h b/src/kernel/free_vars.h index c1ee05dae..a00d39a14 100644 --- a/src/kernel/free_vars.h +++ b/src/kernel/free_vars.h @@ -6,65 +6,26 @@ Author: Leonardo de Moura */ #pragma once #include "kernel/expr.h" -#include "kernel/metavar.h" namespace lean { -/** - \brief Return true iff the given expression has free variables. -*/ +/** \brief Return true iff the given expression has free variables. */ bool has_free_vars(expr const & a); -/** - \brief Return true iff the given expression does not have free variables. -*/ +/** \brief Return true iff the given expression does not have free variables. */ inline bool closed(expr const & a) { return !has_free_vars(a); } -class metavar_env; /** \brief Return \c R s.t. the de Bruijn index of all free variables occurring in \c e is in the interval [0, R). - - \pre All metavariables occurring in \c e must have been created - at \c menv. - - \remark Regarding metavariables, if a metavariable \c m was defined - in a context \c ctx and ctx.size() == R, then \c m can - only contain free variables in the range [0, R) - - So, if \c m does not have an associated local context, the answer is just \c R. - If \c m has an associated local context, we process it using the following rules - - [inst:s v] R ===> if s >= R then R else max(R-1, range_of(v)) - [lift:s:n] R ===> if s >= R then R else R + n */ -unsigned free_var_range(expr const & e, ro_metavar_env const & menv); unsigned free_var_range(expr const & e); /** \brief Return true iff \c e constains a free variable (var i) s.t. \c i in [low, high). \pre low < high - - \remark If menv is not none, then we use \c free_var_range to compute the free variables that may - occur in a metavariable. */ -bool has_free_var(expr const & e, unsigned low, unsigned high, optional const & menv); -bool has_free_var(expr const & e, unsigned low, unsigned high, ro_metavar_env const & menv); bool has_free_var(expr const & e, unsigned low, unsigned high); -/** - \brief Return true iff \c e contains the free variable (var i). -*/ -bool has_free_var(expr const & e, unsigned i, optional const & menv); -bool has_free_var(expr const & e, unsigned i, ro_metavar_env const & menv); +/** \brief Return true iff \c e contains the free variable (var i). */ bool has_free_var(expr const & e, unsigned i); - -bool has_free_var(context_entry const & e, unsigned low, unsigned high, ro_metavar_env const & menv); - -/** - \brief Return true iff \c e contains a free variable >= low. - - \remark If menv is provided, then we use \c free_var_range to compute the free variables that may - occur in a metavariable. -*/ -bool has_free_var_ge(expr const & e, unsigned low, ro_metavar_env const & menv); -bool has_free_var_ge(expr const & e, unsigned low, optional const & menv); +/** \brief Return true iff \c e contains a free variable >= low. */ bool has_free_var_ge(expr const & e, unsigned low); /** @@ -73,30 +34,11 @@ bool has_free_var_ge(expr const & e, unsigned low); \pre s >= d \pre !has_free_var(e, s-d, s, menv) - - \remark The parameter menv is only used for debugging purposes */ -expr lower_free_vars(expr const & e, unsigned s, unsigned d, optional const & menv); -expr lower_free_vars(expr const & e, unsigned s, unsigned d, ro_metavar_env const & menv); expr lower_free_vars(expr const & e, unsigned s, unsigned d); -expr lower_free_vars(expr const & e, unsigned d, optional const & menv); -expr lower_free_vars(expr const & e, unsigned d, ro_metavar_env const & menv); expr lower_free_vars(expr const & e, unsigned d); -context_entry lower_free_vars(context_entry const & e, unsigned s, unsigned d, ro_metavar_env const & menv); - -/** - \brief Lift free variables >= s in \c e by d. - - \remark When the parameter menv is not none, this function will minimize the use - of the local entry lift in metavariables occurring in \c e. -*/ -expr lift_free_vars(expr const & e, unsigned s, unsigned d, optional const & menv); +/** \brief Lift free variables >= s in \c e by d. */ expr lift_free_vars(expr const & e, unsigned s, unsigned d); -expr lift_free_vars(expr const & e, unsigned s, unsigned d, ro_metavar_env const & menv); -expr lift_free_vars(expr const & e, unsigned d, optional const & menv); -expr lift_free_vars(expr const & e, unsigned d, ro_metavar_env const & menv); expr lift_free_vars(expr const & e, unsigned d); - -context_entry lift_free_vars(context_entry const & e, unsigned s, unsigned d, ro_metavar_env const & menv); }