90 lines
2.9 KiB
C++
90 lines
2.9 KiB
C++
/*
|
|
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
|
|
Released under Apache 2.0 license as described in the file LICENSE.
|
|
|
|
Author: Leonardo de Moura
|
|
*/
|
|
#include <algorithm>
|
|
#include <utility>
|
|
#include <vector>
|
|
#include "kernel/abstract.h"
|
|
#include "kernel/replace_fn.h"
|
|
|
|
namespace lean {
|
|
expr abstract(expr const & e, unsigned n, expr const * subst) {
|
|
lean_assert(std::all_of(subst, subst+n, [](expr const & e) { return !has_loose_bvars(e) && is_fvar(e); }));
|
|
if (!has_fvar(e))
|
|
return e;
|
|
return replace(e, [=](expr const & m, unsigned offset) -> optional<expr> {
|
|
if (!has_fvar(m))
|
|
return some_expr(m); // expression m does not contain free variables
|
|
if (is_fvar(m)) {
|
|
unsigned i = n;
|
|
while (i > 0) {
|
|
--i;
|
|
if (fvar_name(subst[i]) == fvar_name(m))
|
|
return some_expr(mk_bvar(offset + n - i - 1));
|
|
}
|
|
return none_expr();
|
|
}
|
|
return none_expr();
|
|
});
|
|
}
|
|
|
|
expr abstract(expr const & e, name const & n) {
|
|
expr fvar = mk_fvar(n);
|
|
return abstract(e, 1, &fvar);
|
|
}
|
|
|
|
extern "C" object * lean_expr_abstract(object * e0, object * subst) {
|
|
expr const & e = reinterpret_cast<expr const &>(e0);
|
|
if (!has_fvar(e)) {
|
|
lean_inc(e0);
|
|
return e0;
|
|
}
|
|
size_t n = lean_array_size(subst);
|
|
expr r = replace(e, [=](expr const & m, unsigned offset) -> optional<expr> {
|
|
if (!has_fvar(m))
|
|
return some_expr(m); // expression m does not contain free variables
|
|
if (is_fvar(m)) {
|
|
size_t i = n;
|
|
while (i > 0) {
|
|
--i;
|
|
if (fvar_name_core(lean_array_get_core(subst, i)) == fvar_name(m))
|
|
return some_expr(mk_bvar(offset + n - i - 1));
|
|
}
|
|
return none_expr();
|
|
}
|
|
return none_expr();
|
|
});
|
|
return r.steal();
|
|
}
|
|
|
|
|
|
/* ------ LEGACY CODE -------------
|
|
The following API is to support legacy
|
|
code where the type of a local constant (aka free variable)
|
|
was stored in the local constant itself.
|
|
This approach was used in Lean2, and is being abandoned in Lean4.
|
|
|
|
TODO(Leo): delete */
|
|
|
|
template<bool is_lambda>
|
|
expr mk_binding(unsigned num, expr const * locals, expr const & b) {
|
|
expr r = abstract(b, num, locals);
|
|
unsigned i = num;
|
|
while (i > 0) {
|
|
--i;
|
|
expr const & l = locals[i];
|
|
expr t = abstract(local_type(l), i, locals);
|
|
if (is_lambda)
|
|
r = mk_lambda(local_pp_name(l), t, r, local_info(l));
|
|
else
|
|
r = mk_pi(local_pp_name(l), t, r, local_info(l));
|
|
}
|
|
return r;
|
|
}
|
|
|
|
expr Pi(unsigned num, expr const * locals, expr const & b) { return mk_binding<false>(num, locals, b); }
|
|
expr Fun(unsigned num, expr const * locals, expr const & b) { return mk_binding<true>(num, locals, b); }
|
|
}
|