39 lines
1.1 KiB
C
39 lines
1.1 KiB
C
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/*
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Copyright (c) 2014 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 "util/lua.h"
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#include "kernel/expr.h"
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namespace lean {
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/**
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\brief Create a choice expression for the given expressions.
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The elaborator decides which one should be used based on the type of the arguments.
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\remark if num_fs == 1, then return fs[0]
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\pre num_fs >= 1
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*/
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expr mk_choice(unsigned num_es, expr const * es);
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/** \brief Return true iff \c e is an expression created using \c mk_choice. */
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bool is_choice(expr const & e);
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/**
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\brief Return the number of alternatives in a choice expression.
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We have that <tt>get_num_choices(mk_choice(n, es)) == n</tt> whenever <tt>n >= 2</tt>.
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\pre is_choice(e)
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*/
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unsigned get_num_choices(expr const & e);
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/**
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\brief Return the (i+1)-th alternative of a choice expression.
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\pre is_choice(e)
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\pre i < get_num_choices(e)
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*/
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expr const & get_choice(expr const & e, unsigned i);
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void open_choice(lua_State * L);
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}
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