1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
#![allow(deprecated)]
use crate::engine::facts::Facts;
use crate::engine::rule::ConditionGroup;
use std::collections::HashMap;
/// Pattern matching evaluator for advanced condition types
pub struct PatternMatcher;
impl PatternMatcher {
/// Evaluate EXISTS condition - checks if at least one fact matches the condition
pub fn evaluate_exists(condition: &ConditionGroup, facts: &Facts) -> bool {
let all_facts = facts.get_all_facts();
// For EXISTS, we need to check if ANY fact matches the condition
// We iterate through all facts and check if the condition matches any of them
for (fact_name, fact_value) in &all_facts {
// Extract the target type from the condition if it's a single condition
if let Some(target_type) = Self::extract_target_type(condition) {
// Check if fact name starts with target type (e.g., "Customer1" starts with "Customer")
if fact_name.starts_with(&target_type) {
// Create a temporary fact context with the target type as key
// This allows condition evaluation to work with "Customer.tier" syntax
let mut temp_facts = HashMap::new();
temp_facts.insert(target_type.clone(), fact_value.clone());
// This fact matches the target type, evaluate the condition
if condition.evaluate(&temp_facts) {
return true;
}
}
} else {
// For complex conditions, evaluate against all facts
if condition.evaluate(&all_facts) {
return true;
}
}
}
false
}
/// Evaluate NOT condition - checks if no facts match the condition
pub fn evaluate_not(condition: &ConditionGroup, facts: &Facts) -> bool {
// NOT is simply the opposite of EXISTS
!Self::evaluate_exists(condition, facts)
}
/// Evaluate FORALL condition - checks if all facts of target type match the condition
pub fn evaluate_forall(condition: &ConditionGroup, facts: &Facts) -> bool {
let all_facts = facts.get_all_facts();
// Extract the target type from condition
let target_type = match Self::extract_target_type(condition) {
Some(t) => t,
None => {
// If we can't determine target type, evaluate against all facts
return condition.evaluate(&all_facts);
}
};
// Find all facts of the target type (including numbered variants like Customer1, Customer2)
let mut target_facts = Vec::new();
for (fact_name, fact_value) in &all_facts {
// Check if fact name starts with target type (e.g., Customer1, Customer2, Customer3)
// OR exact match (e.g., Customer)
if fact_name.starts_with(&target_type) || fact_name == &target_type {
target_facts.push((fact_name, fact_value));
}
}
// If no facts of target type exist, FORALL is vacuously true
if target_facts.is_empty() {
return true;
}
// Check if ALL facts of target type match the condition
for (_fact_name, fact_value) in target_facts {
// Create a temporary fact context with the target type as key
// This allows condition evaluation to work with "Order.status" syntax
let mut temp_facts = HashMap::new();
temp_facts.insert(target_type.clone(), fact_value.clone());
if !condition.evaluate(&temp_facts) {
return false; // Found a fact that doesn't match
}
}
true // All facts matched
}
/// Extract the target fact type from a condition (e.g., "Customer" from "Customer.tier == 'VIP'")
fn extract_target_type(condition: &ConditionGroup) -> Option<String> {
match condition {
ConditionGroup::Single(cond) => {
// Extract the object name from field path (e.g., "Customer.tier" -> "Customer")
if let Some(dot_pos) = cond.field.find('.') {
Some(cond.field[..dot_pos].to_string())
} else {
Some(cond.field.clone())
}
}
ConditionGroup::Compound { left, .. } => {
// For compound conditions, try to extract from left side
Self::extract_target_type(left)
}
_ => None,
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::engine::rule::Condition;
use crate::types::{Operator, Value};
use std::collections::HashMap;
#[test]
fn test_exists_pattern_matching() {
let facts = Facts::new();
// Add some test facts
let mut customer1 = HashMap::new();
customer1.insert("tier".to_string(), Value::String("VIP".to_string()));
facts
.add_value("Customer1", Value::Object(customer1))
.unwrap();
let mut customer2 = HashMap::new();
customer2.insert("tier".to_string(), Value::String("Regular".to_string()));
facts
.add_value("Customer2", Value::Object(customer2))
.unwrap();
// Test EXISTS condition: exists(Customer.tier == "VIP")
let condition = ConditionGroup::Single(Condition::new(
"Customer1.tier".to_string(),
Operator::Equal,
Value::String("VIP".to_string()),
));
assert!(PatternMatcher::evaluate_exists(&condition, &facts));
// Test EXISTS condition that should fail
let condition_fail = ConditionGroup::Single(Condition::new(
"Customer1.tier".to_string(),
Operator::Equal,
Value::String("Premium".to_string()),
));
assert!(!PatternMatcher::evaluate_exists(&condition_fail, &facts));
}
#[test]
fn test_not_pattern_matching() {
let facts = Facts::new();
// Add test fact
let mut customer = HashMap::new();
customer.insert("tier".to_string(), Value::String("Regular".to_string()));
facts
.add_value("Customer", Value::Object(customer))
.unwrap();
// Test NOT condition: not(Customer.tier == "VIP")
let condition = ConditionGroup::Single(Condition::new(
"Customer.tier".to_string(),
Operator::Equal,
Value::String("VIP".to_string()),
));
assert!(PatternMatcher::evaluate_not(&condition, &facts));
// Test NOT condition that should fail
let condition_fail = ConditionGroup::Single(Condition::new(
"Customer.tier".to_string(),
Operator::Equal,
Value::String("Regular".to_string()),
));
assert!(!PatternMatcher::evaluate_not(&condition_fail, &facts));
}
#[test]
fn test_forall_pattern_matching() {
let facts = Facts::new();
// Add multiple customers, all VIP
let mut customer1 = HashMap::new();
customer1.insert("tier".to_string(), Value::String("VIP".to_string()));
facts
.add_value("Customer1", Value::Object(customer1))
.unwrap();
let mut customer2 = HashMap::new();
customer2.insert("tier".to_string(), Value::String("VIP".to_string()));
facts
.add_value("Customer2", Value::Object(customer2))
.unwrap();
// Test FORALL condition: forall(Customer.tier == "VIP")
// This should match Customer1, Customer2, etc.
let condition = ConditionGroup::Single(Condition::new(
"Customer.tier".to_string(), // Generic pattern to match all Customer*
Operator::Equal,
Value::String("VIP".to_string()),
));
assert!(PatternMatcher::evaluate_forall(&condition, &facts));
// Add a non-VIP customer
let mut customer3 = HashMap::new();
customer3.insert("tier".to_string(), Value::String("Regular".to_string()));
facts
.add_value("Customer3", Value::Object(customer3))
.unwrap();
// Now FORALL should fail
assert!(!PatternMatcher::evaluate_forall(&condition, &facts));
}
#[test]
fn test_extract_target_type() {
let condition = ConditionGroup::Single(Condition::new(
"Customer.tier".to_string(),
Operator::Equal,
Value::String("VIP".to_string()),
));
assert_eq!(
PatternMatcher::extract_target_type(&condition),
Some("Customer".to_string())
);
let simple_condition = ConditionGroup::Single(Condition::new(
"Customer".to_string(),
Operator::Equal,
Value::String("VIP".to_string()),
));
assert_eq!(
PatternMatcher::extract_target_type(&simple_condition),
Some("Customer".to_string())
);
}
}