1 /*
2 * Copyright (C) 2018 The Android Open Source Project
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 #include "utils/grammar/semantics/evaluators/arithmetic-eval.h"
18
19 #include <limits>
20
21 namespace libtextclassifier3::grammar {
22 namespace {
23
24 template <typename T>
Reduce(const SemanticExpressionEvaluator * composer,const EvalContext & context,const ArithmeticExpression * expression,UnsafeArena * arena)25 StatusOr<const SemanticValue*> Reduce(
26 const SemanticExpressionEvaluator* composer, const EvalContext& context,
27 const ArithmeticExpression* expression, UnsafeArena* arena) {
28 T result;
29 switch (expression->op()) {
30 case ArithmeticExpression_::Operator_OP_ADD: {
31 result = 0;
32 break;
33 }
34 case ArithmeticExpression_::Operator_OP_MUL: {
35 result = 1;
36 break;
37 }
38 case ArithmeticExpression_::Operator_OP_MIN: {
39 result = std::numeric_limits<T>::max();
40 break;
41 }
42 case ArithmeticExpression_::Operator_OP_MAX: {
43 result = std::numeric_limits<T>::min();
44 break;
45 }
46 default: {
47 return Status(StatusCode::INVALID_ARGUMENT,
48 "Unexpected op: " +
49 std::string(ArithmeticExpression_::EnumNameOperator(
50 expression->op())));
51 }
52 }
53 if (expression->values() != nullptr) {
54 for (const SemanticExpression* semantic_expression :
55 *expression->values()) {
56 TC3_ASSIGN_OR_RETURN(
57 const SemanticValue* value,
58 composer->Apply(context, semantic_expression, arena));
59 if (value == nullptr) {
60 continue;
61 }
62 if (!value->Has<T>()) {
63 return Status(
64 StatusCode::INVALID_ARGUMENT,
65 "Argument didn't evaluate as expected type: " +
66 std::string(reflection::EnumNameBaseType(value->base_type())));
67 }
68 const T scalar_value = value->Value<T>();
69 switch (expression->op()) {
70 case ArithmeticExpression_::Operator_OP_ADD: {
71 result += scalar_value;
72 break;
73 }
74 case ArithmeticExpression_::Operator_OP_MUL: {
75 result *= scalar_value;
76 break;
77 }
78 case ArithmeticExpression_::Operator_OP_MIN: {
79 result = std::min(result, scalar_value);
80 break;
81 }
82 case ArithmeticExpression_::Operator_OP_MAX: {
83 result = std::max(result, scalar_value);
84 break;
85 }
86 default: {
87 break;
88 }
89 }
90 }
91 }
92 return SemanticValue::Create(result, arena);
93 }
94
95 } // namespace
96
Apply(const EvalContext & context,const SemanticExpression * expression,UnsafeArena * arena) const97 StatusOr<const SemanticValue*> ArithmeticExpressionEvaluator::Apply(
98 const EvalContext& context, const SemanticExpression* expression,
99 UnsafeArena* arena) const {
100 TC3_DCHECK_EQ(expression->expression_type(),
101 SemanticExpression_::Expression_ArithmeticExpression);
102 const ArithmeticExpression* arithmetic_expression =
103 expression->expression_as_ArithmeticExpression();
104 switch (arithmetic_expression->base_type()) {
105 case reflection::BaseType::Byte:
106 return Reduce<int8>(composer_, context, arithmetic_expression, arena);
107 case reflection::BaseType::UByte:
108 return Reduce<uint8>(composer_, context, arithmetic_expression, arena);
109 case reflection::BaseType::Short:
110 return Reduce<int16>(composer_, context, arithmetic_expression, arena);
111 case reflection::BaseType::UShort:
112 return Reduce<uint16>(composer_, context, arithmetic_expression, arena);
113 case reflection::BaseType::Int:
114 return Reduce<int32>(composer_, context, arithmetic_expression, arena);
115 case reflection::BaseType::UInt:
116 return Reduce<uint32>(composer_, context, arithmetic_expression, arena);
117 case reflection::BaseType::Long:
118 return Reduce<int64>(composer_, context, arithmetic_expression, arena);
119 case reflection::BaseType::ULong:
120 return Reduce<uint64>(composer_, context, arithmetic_expression, arena);
121 case reflection::BaseType::Float:
122 return Reduce<float>(composer_, context, arithmetic_expression, arena);
123 case reflection::BaseType::Double:
124 return Reduce<double>(composer_, context, arithmetic_expression, arena);
125 default:
126 return Status(StatusCode::INVALID_ARGUMENT,
127 "Unsupported for ArithmeticExpression: " +
128 std::string(reflection::EnumNameBaseType(
129 static_cast<reflection::BaseType>(
130 arithmetic_expression->base_type()))));
131 }
132 }
133
134 } // namespace libtextclassifier3::grammar
135