hamelin_eval 0.10.12

Expression evaluation for Hamelin query language
Documentation 
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

use crate::eval::environment::Environment;
use crate::eval::evaluator::eval;
use crate::value::Value;
use hamelin_lib::tree::builder::{add, field_ref, is_not_null, is_null, null, ExpressionBuilder};
use hamelin_lib::tree::options::ExpressionTypeCheckOptions;
use hamelin_lib::type_check_expression;
use hamelin_lib::types::INT;
use std::sync::Arc;

use super::test_helpers::TestContext;

#[test]
fn test_eval_null_propagation() {
    let mut ctx = TestContext::default();
    ctx.set("x", Value::Null, INT);

    // Test: x + 5 should return null (null propagation)
    let expr = type_check_expression(
        add(field_ref("x"), 5).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();

    assert_eq!(result, Value::Null);
    assert!(result.is_null());
}

#[test]
fn test_eval_is_null_operators() {
    let env = Environment::new();

    // Test IS NULL with null value
    let expr = type_check_expression(
        is_null(null()).build(),
        ExpressionTypeCheckOptions::default(),
    )
    .output;
    let result = eval(&expr, &env).unwrap();
    assert_eq!(result, Value::Boolean(true));

    // Test IS NOT NULL with non-null value
    let expr = type_check_expression(
        is_not_null(42).build(),
        ExpressionTypeCheckOptions::default(),
    )
    .output;
    let result = eval(&expr, &env).unwrap();
    assert_eq!(result, Value::Boolean(true));

    // Test IS NULL with non-null value
    let expr =
        type_check_expression(is_null(42).build(), ExpressionTypeCheckOptions::default()).output;
    let result = eval(&expr, &env).unwrap();
    assert_eq!(result, Value::Boolean(false));

    // Test IS NOT NULL with null value
    let expr = type_check_expression(
        is_not_null(null()).build(),
        ExpressionTypeCheckOptions::default(),
    )
    .output;
    let result = eval(&expr, &env).unwrap();
    assert_eq!(result, Value::Boolean(false));
}

#[test]
fn test_eval_null_literal() {
    let ctx = TestContext::new();

    // Test null literal evaluation
    let expr = null();
    let result = ctx.eval_expr(&expr);
    assert_eq!(result, Value::Null);
    assert!(result.is_null());
}

#[test]
fn test_null_propagation_in_arithmetic() {
    let mut ctx = TestContext::default();
    ctx.set("null_var", Value::Null, INT);
    ctx.set("null_var2", Value::Null, INT);

    // Test null + number = null
    let expr = type_check_expression(
        add(field_ref("null_var"), 42).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();
    assert_eq!(result, Value::Null);

    // Test number + null = null
    let expr = type_check_expression(
        add(42, field_ref("null_var")).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();
    assert_eq!(result, Value::Null);

    // Test null + null = null
    let expr = type_check_expression(
        add(field_ref("null_var"), field_ref("null_var2")).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();
    assert_eq!(result, Value::Null);
}

#[test]
fn test_null_propagation_in_comparisons() {
    use hamelin_lib::tree::builder::{eq, gt};

    let mut ctx = TestContext::default();
    ctx.set("null_var", Value::Null, INT);
    ctx.set("null_var2", Value::Null, INT);

    // Test null = number should return null (three-valued logic)
    let expr = type_check_expression(
        eq(field_ref("null_var"), 42).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();
    assert_eq!(result, Value::Null);

    // Test number = null should return null
    let expr = type_check_expression(
        eq(42, field_ref("null_var")).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();
    assert_eq!(result, Value::Null);

    // Test null = null should return null
    let expr = type_check_expression(
        eq(field_ref("null_var"), field_ref("null_var2")).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();
    assert_eq!(result, Value::Null);

    // Test null > number should return null
    let expr = type_check_expression(
        gt(field_ref("null_var"), 42).build(),
        ExpressionTypeCheckOptions::builder()
            .bindings(Arc::new(ctx.translation_env.clone()))
            .build(),
    )
    .output;
    let result = eval(&expr, &ctx.env).unwrap();
    assert_eq!(result, Value::Null);
}