76 lines
2.3 KiB
C++
76 lines
2.3 KiB
C++
/*
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Copyright (c) 2013 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Leonardo de Moura
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*/
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#pragma once
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#include <tuple>
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#include "util/buffer.h"
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#include "util/interrupt.h"
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#include "kernel/expr.h"
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#include "kernel/expr_maps.h"
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namespace lean {
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/**
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\brief Default replace_fn postprocessor functional object. It is a
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do-nothing object.
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*/
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class default_replace_postprocessor {
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public:
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void operator()(expr const &, expr const &) {}
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};
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/**
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\brief Functional for applying <tt>F</tt> to the subexpressions of a given expression.
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The signature of \c F is
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expr const &, unsigned -> optional(expr)
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F is invoked for each subexpression \c s of the input expression e.
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In a call <tt>F(s, n)</tt>, n is the scope level, i.e., the number of
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bindings operators that enclosing \c s. The replaces only visits children of \c e
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if F return none_expr
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P is a "post-processing" functional object that is applied to each
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pair (old, new)
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*/
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class replace_fn {
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struct frame {
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expr m_expr;
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unsigned m_offset;
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bool m_shared;
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unsigned m_index;
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frame(expr const & e, unsigned o, bool s):m_expr(e), m_offset(o), m_shared(s), m_index(0) {}
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};
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typedef buffer<frame> frame_stack;
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typedef buffer<expr> result_stack;
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expr_cell_offset_map<expr> m_cache;
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std::function<optional<expr>(expr const &, unsigned)> m_f;
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std::function<void(expr const &, expr const &)> m_post;
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frame_stack m_fs;
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result_stack m_rs;
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void save_result(expr const & e, expr const & r, unsigned offset, bool shared);
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bool visit(expr const & e, unsigned offset);
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bool check_index(frame & f, unsigned idx);
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expr const & rs(int i);
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void pop_rs(unsigned num);
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public:
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template<typename F, typename P = default_replace_postprocessor>
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replace_fn(F const & f, P const & p = P()):
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m_f(f), m_post(p) {}
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expr operator()(expr const & e);
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void clear();
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};
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template<typename F> expr replace(expr const & e, F const & f) {
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return replace_fn(f)(e);
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}
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template<typename F, typename P> expr replace(expr const & e, F const & f, P const & p) {
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return replace_fn(f, p)(e);
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}
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}
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