lean4-htt/src/library/local_context.h

158 lines
7.2 KiB
C++

/*
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#pragma once
#include "util/name_map.h"
#include "util/name_set.h"
#include "kernel/local_ctx.h"
#include "kernel/expr.h"
#include "library/formatter.h"
#include "library/subscripted_name_set.h"
namespace lean {
bool is_local_decl_ref(expr const & e);
class metavar_context;
class local_context;
bool depends_on(expr const & e, metavar_context const & mctx, unsigned num, expr const * locals);
bool depends_on(local_decl const & d, metavar_context const & mctx, unsigned num, expr const * locals);
bool depends_on(expr const & e, metavar_context const & mctx, buffer<expr> const & locals);
bool depends_on(local_decl const & d, metavar_context const & mctx, buffer<expr> const & locals);
/* Similar to depends_on(expr const & e, metavar_context const & mctx, unsigned num, expr const * locals), but it
will also visit the value v of local definitions (x : t := v) if x occurs in e (directly or indirectly). */
bool depends_on(expr const & e, metavar_context const & mctx, local_context const & lctx, unsigned num, expr const * locals);
inline bool depends_on(expr const & e, metavar_context const & mctx, local_context const & lctx, expr const & local) {
return depends_on(e, mctx, lctx, 1, &local);
}
/* Create an unieq local_decl name.
This is a low-level function. The high-level methods
at local_context use this function internally. */
name mk_local_decl_name();
class metavar_context;
/* Extend kernel local context object with support for generating "unused" user-names and
"freezing" local instances. */
class local_context : public local_ctx {
typedef rb_tree<unsigned, unsigned_cmp> unsigned_set;
/* support for user names */
subscripted_name_set m_user_names;
name_map<unsigned_set> m_user_name2idxs;
friend class type_context_old;
void insert_user_name(local_decl const & d);
void erase_user_name(local_decl const & d);
local_context remove(buffer<expr> const & locals) const;
expr mk_local_decl(name const & n, name const & un, expr const & type,
optional<expr> const & value, binder_info bi);
static local_decl update_local_decl(local_decl const & d, expr const & t,
optional<expr> const & v) {
if (v) return local_decl(d, t, *v);
else return local_decl(d, t);
}
public:
local_context() {}
explicit local_context(local_ctx const & lctx): local_ctx(lctx) {}
bool empty() const { return m_idx2local_decl.empty(); }
expr mk_local_decl(expr const & type, binder_info bi = mk_binder_info());
expr mk_local_decl(expr const & type, expr const & value);
expr mk_local_decl(name const & un, expr const & type, binder_info bi = mk_binder_info());
expr mk_local_decl(name const & un, expr const & type, expr const & value);
/* Low-level version of the methods above.
\pre `n` was created using mk_local_decl_name
\pre there is no local_decl named `n` in this local_context. */
expr mk_local_decl(name const & n, name const & un, expr const & type, binder_info bi = mk_binder_info());
expr mk_local_decl(name const & n, name const & un, expr const & type, expr const & value);
/** \brief Return the most recently added local_decl \c d s.t. d.get_user_name() == n
\remark This method is used to implement tactics such as 'revert'. */
optional<local_decl> find_local_decl_from_user_name(name const & n) const;
optional<local_decl> find_last_local_decl() const;
local_decl get_last_local_decl() const;
bool rename_user_name(name const & from, name const & to);
/** \brief Execute fn for each local declaration created after \c d. */
void for_each_after(local_decl const & d, std::function<void(local_decl const &)> const & fn) const;
/** \brief Return a non-none iff other local decls depends on \c d. If the result is not none,
then it is the name of the local decl that depends on d.
\pre \c d is in this local context. */
optional<local_decl> has_dependencies(local_decl const & d, metavar_context const & mctx) const;
/** \brief Return an unused hypothesis "user name" with the given prefix, the suffix is an
unsigned >= idx. */
name get_unused_name(name const & prefix, unsigned & idx) const;
name get_unused_name(name const & suggestion) const;
/** \brief Return true iff the given name is a hypothesis "user name". */
bool uses_user_name(name const & n) const;
/** \brief Remove the given local decl. */
void clear(local_decl const & d);
/** \brief Return true iff all locals in this context are in the set \c ls. */
bool is_subset_of(name_set const & ls) const;
/** \brief Return true iff all locals in this context are also in \c ctx. */
bool is_subset_of(local_context const & ctx) const;
void pop_local_decl();
/** \brief We say a local context is well-formed iff all local declarations only
contain local_decl references that were defined before them.
\remark This method is for debugging purposes. */
bool well_formed() const;
/** \brief Return true iff \c e is well-formed with respect to this local context.
That is, all local_decl references in \c e are defined in this context. */
bool well_formed(expr const & e) const;
format pp(formatter const & fmt, std::function<bool(local_decl const &)> const & pred) const; // NOLINT
format pp(formatter const & fmt) const { return pp(fmt, [](local_decl const &) { return true; }); }
/** \brief Replaced assigned metavariables with their values.
This method is a little bit hackish since it reuses the names and ids of
the existing local_decls. So, it may affect cached information.
This method is mainly used in the elaborator for reporting errors,
and for instantiating metavariables created by the elaborator before
invoking the tactic framework. */
local_context instantiate_mvars(metavar_context & ctx) const;
friend bool is_decl_eqp(local_context const & ctx1, local_context const & ctx2) {
return is_eqp(ctx1.m_name2local_decl, ctx2.m_name2local_decl);
}
friend bool equal_locals(local_context const & ctx1, local_context const & ctx2) {
return is_decl_eqp(ctx1, ctx2) || ctx1.m_name2local_decl.equal_keys(ctx2.m_name2local_decl);
}
/** \brief Erase inaccessible annotations from the local context.
This function is defined in the file library/equations_compiler/util.h.
It is a little bit hackish (like instantiate_mvars) since it reuses the names
and ids of existing local_decls. So, it may affect cached information.
This function is used in the elaborator before invoking the tactic framework. */
friend local_context erase_inaccessible_annotations(local_context const & lctx);
};
/** \brief Return true iff `e` contains a local_decl_ref that contains a value */
bool contains_let_local_decl(local_context const & lctx, expr const & e);
/** \brief Expand all local_decl_refs (that have values) in `e` */
expr zeta_expand(local_context const & lctx, expr const & e);
void initialize_local_context();
void finalize_local_context();
}