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      1 /*
      2  * Copyright 2014 Google Inc. All rights reserved.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef FRUIT_PROOF_TREE_COMPARISON_H
     18 #define FRUIT_PROOF_TREE_COMPARISON_H
     19 
     20 #if !FRUIT_EXTRA_DEBUG && !FRUIT_IN_META_TEST
     21 #error "This file should only be included in debug mode or in tests."
     22 #endif
     23 
     24 namespace fruit {
     25 namespace impl {
     26 namespace meta {
     27 
     28 // Checks whether Proof is entailed by Forest, i.e. whether there is a corresponding Proof1 in Forest with the same
     29 // thesis
     30 // and with the same hypotheses as Proof (or a subset).
     31 struct IsProofEntailedByForest {
     32   template <typename ProofTh, typename ProofHps, typename Forest>
     33   struct apply {
     34     using ForestHps = FindInMap(Forest, ProofTh);
     35     using type = If(IsNone(ForestHps), Bool<false>, IsContained(ForestHps, ProofHps));
     36   };
     37 };
     38 
     39 struct IsForestEntailedByForest {
     40   template <typename EntailedForest, typename Forest>
     41   struct apply {
     42     struct Helper {
     43       template <typename CurrentResult, typename EntailedProof>
     44       struct apply;
     45 
     46       template <typename CurrentResult, typename EntailedProofTh, typename EntailedProofHps>
     47       struct apply<CurrentResult, Pair<EntailedProofTh, EntailedProofHps>> {
     48         using type = And(CurrentResult, IsProofEntailedByForest(EntailedProofTh, EntailedProofHps, Forest));
     49       };
     50     };
     51 
     52     using type = FoldVector(EntailedForest, Helper, Bool<true>);
     53   };
     54 };
     55 
     56 // Given two proof trees, check if they are equal.
     57 // Only for debugging.
     58 struct IsProofTreeEqualTo {
     59   template <typename Proof1, typename Proof2>
     60   struct apply {
     61     using type = And(IsSame(typename Proof1::First, typename Proof2::First),
     62                      IsSameSet(typename Proof1::Second, typename Proof2::Second));
     63   };
     64 };
     65 
     66 // Given two proofs forests, check if they are equal.
     67 // This is not very efficient, consider re-implementing if it will be used often.
     68 // Only for debugging.
     69 struct IsForestEqualTo {
     70   template <typename Forest1, typename Forest2>
     71   struct apply {
     72     using type = And(IsForestEntailedByForest(Forest1, Forest2), IsForestEntailedByForest(Forest2, Forest1));
     73   };
     74 };
     75 
     76 // Only for debugging, similar to checking IsProofEntailedByForest but gives a detailed error.
     77 // Only for debugging.
     78 struct CheckProofEntailedByForest {
     79   template <typename ProofTh, typename ProofHps, typename Forest>
     80   struct apply {
     81     using ForestHps = FindInMap(Forest, ProofTh);
     82     using type = If(IsNone(ForestHps),
     83                     ConstructError(ProofNotEntailedByForestBecauseThNotFoundErrorTag, ProofTh, GetMapKeys(Forest)),
     84                     If(IsContained(ForestHps, ProofHps), Bool<true>,
     85                        ConstructError(ProofNotEntailedByForestBecauseHpsNotASubsetErrorTag, ForestHps, ProofHps,
     86                                       SetDifference(ForestHps, ProofHps))));
     87   };
     88 };
     89 
     90 // Only for debugging, similar to checking IsProofEntailedByForest but gives a detailed error.
     91 // Only for debugging.
     92 struct CheckForestEntailedByForest {
     93   template <typename EntailedForest, typename Forest>
     94   struct apply {
     95     struct Helper {
     96       template <typename CurrentResult, typename EntailedProof>
     97       struct apply;
     98 
     99       template <typename CurrentResult, typename EntailedProofTh, typename EntailedProofHps>
    100       struct apply<CurrentResult, Pair<EntailedProofTh, EntailedProofHps>> {
    101         using type = PropagateError(CurrentResult,
    102                                     CheckProofEntailedByForest(EntailedProofTh, EntailedProofHps, Forest));
    103       };
    104     };
    105 
    106     using type = FoldVector(EntailedForest, Helper, Bool<true>);
    107   };
    108 };
    109 
    110 // Given two proofs forests, check if they are equal.
    111 // This is not very efficient, consider re-implementing if it will be used often.
    112 // Only for debugging.
    113 struct CheckForestEqualTo {
    114   template <typename Forest1, typename Forest2>
    115   struct apply {
    116     using type = PropagateError(CheckForestEntailedByForest(Forest1, Forest2),
    117                                 CheckForestEntailedByForest(Forest2, Forest1));
    118   };
    119 };
    120 
    121 } // namespace meta
    122 } // namespace impl
    123 } // namespace fruit
    124 
    125 #endif // FRUIT_PROOF_TREE_COMPARISON_H
    126