27 lines
731 B
C++
27 lines
731 B
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 "kernel/for_each_fn.h"
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#include "kernel/expr.h"
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namespace lean {
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/** \brief Return a subexpression of \c e that satisfies the predicate \c p. */
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template<typename P> optional<expr> find(expr const & e, P p) {
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optional<expr> result;
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for_each(e, [&](expr const & e, unsigned offset) {
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if (result) {
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return false;
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} else if (p(e, offset)) {
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result = e;
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return false;
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} else {
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return true;
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}
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});
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return result;
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}
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}
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