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runmat_runtime/builtins/strings/core/
strcmp.rs

1//! MATLAB-compatible `strcmp` builtin for RunMat.
2
3use runmat_builtins::Value;
4use runmat_macros::runtime_builtin;
5
6use crate::builtins::common::broadcast::{broadcast_index, broadcast_shapes, compute_strides};
7use crate::builtins::common::map_control_flow_with_builtin;
8use crate::builtins::common::spec::{
9    BroadcastSemantics, BuiltinFusionSpec, BuiltinGpuSpec, ConstantStrategy, GpuOpKind,
10    ReductionNaN, ResidencyPolicy, ShapeRequirements,
11};
12use crate::builtins::common::tensor;
13use crate::builtins::strings::search::text_utils::{logical_result, TextCollection, TextElement};
14use crate::builtins::strings::type_resolvers::logical_text_match_type;
15use crate::{build_runtime_error, gather_if_needed_async, BuiltinResult, RuntimeError};
16
17#[runmat_macros::register_gpu_spec(builtin_path = "crate::builtins::strings::core::strcmp")]
18pub const GPU_SPEC: BuiltinGpuSpec = BuiltinGpuSpec {
19    name: "strcmp",
20    op_kind: GpuOpKind::Custom("string-compare"),
21    supported_precisions: &[],
22    broadcast: BroadcastSemantics::Matlab,
23    provider_hooks: &[],
24    constant_strategy: ConstantStrategy::InlineLiteral,
25    residency: ResidencyPolicy::GatherImmediately,
26    nan_mode: ReductionNaN::Include,
27    two_pass_threshold: None,
28    workgroup_size: None,
29    accepts_nan_mode: false,
30    notes: "Performs host-side text comparisons; GPU operands are gathered automatically before evaluation.",
31};
32
33#[runmat_macros::register_fusion_spec(builtin_path = "crate::builtins::strings::core::strcmp")]
34pub const FUSION_SPEC: BuiltinFusionSpec = BuiltinFusionSpec {
35    name: "strcmp",
36    shape: ShapeRequirements::Any,
37    constant_strategy: ConstantStrategy::InlineLiteral,
38    elementwise: None,
39    reduction: None,
40    emits_nan: false,
41    notes: "Produces logical results on the host; not eligible for GPU fusion.",
42};
43
44#[allow(dead_code)]
45fn strcmp_flow(message: impl Into<String>) -> RuntimeError {
46    build_runtime_error(message).with_builtin("strcmp").build()
47}
48
49fn remap_strcmp_flow(err: RuntimeError) -> RuntimeError {
50    map_control_flow_with_builtin(err, "strcmp")
51}
52
53#[runtime_builtin(
54    name = "strcmp",
55    category = "strings/core",
56    summary = "Compare text inputs for exact matches (case-sensitive).",
57    keywords = "strcmp,string compare,text equality",
58    accel = "sink",
59    type_resolver(logical_text_match_type),
60    builtin_path = "crate::builtins::strings::core::strcmp"
61)]
62async fn strcmp_builtin(a: Value, b: Value) -> crate::BuiltinResult<Value> {
63    let a = gather_if_needed_async(&a)
64        .await
65        .map_err(remap_strcmp_flow)?;
66    let b = gather_if_needed_async(&b)
67        .await
68        .map_err(remap_strcmp_flow)?;
69    let left = TextCollection::from_argument("strcmp", a, "first argument")?;
70    let right = TextCollection::from_argument("strcmp", b, "second argument")?;
71    evaluate_strcmp(&left, &right)
72}
73
74fn evaluate_strcmp(left: &TextCollection, right: &TextCollection) -> BuiltinResult<Value> {
75    let shape = broadcast_shapes("strcmp", &left.shape, &right.shape)?;
76    let total = tensor::element_count(&shape);
77    if total == 0 {
78        return logical_result("strcmp", Vec::new(), shape);
79    }
80    let left_strides = compute_strides(&left.shape);
81    let right_strides = compute_strides(&right.shape);
82    let mut data = Vec::with_capacity(total);
83    for linear in 0..total {
84        let li = broadcast_index(linear, &shape, &left.shape, &left_strides);
85        let ri = broadcast_index(linear, &shape, &right.shape, &right_strides);
86        let equal = match (&left.elements[li], &right.elements[ri]) {
87            (TextElement::Missing, _) => false,
88            (_, TextElement::Missing) => false,
89            (TextElement::Text(lhs), TextElement::Text(rhs)) => lhs == rhs,
90        };
91        data.push(if equal { 1 } else { 0 });
92    }
93    logical_result("strcmp", data, shape)
94}
95
96#[cfg(test)]
97pub(crate) mod tests {
98    use super::*;
99    use crate::RuntimeError;
100    use runmat_builtins::{CellArray, CharArray, LogicalArray, ResolveContext, StringArray, Type};
101
102    fn strcmp_builtin(a: Value, b: Value) -> BuiltinResult<Value> {
103        futures::executor::block_on(super::strcmp_builtin(a, b))
104    }
105
106    fn error_message(err: RuntimeError) -> String {
107        err.message().to_string()
108    }
109
110    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
111    #[test]
112    fn strcmp_string_scalar_true() {
113        let result = strcmp_builtin(
114            Value::String("RunMat".into()),
115            Value::String("RunMat".into()),
116        )
117        .expect("strcmp");
118        assert_eq!(result, Value::Bool(true));
119    }
120
121    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
122    #[test]
123    fn strcmp_string_scalar_false() {
124        let result = strcmp_builtin(
125            Value::String("RunMat".into()),
126            Value::String("runmat".into()),
127        )
128        .expect("strcmp");
129        assert_eq!(result, Value::Bool(false));
130    }
131
132    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
133    #[test]
134    fn strcmp_string_array_broadcast_scalar() {
135        let array = StringArray::new(
136            vec!["red".into(), "green".into(), "blue".into()],
137            vec![1, 3],
138        )
139        .unwrap();
140        let result =
141            strcmp_builtin(Value::StringArray(array), Value::String("green".into())).expect("cmp");
142        let expected = LogicalArray::new(vec![0, 1, 0], vec![1, 3]).unwrap();
143        assert_eq!(result, Value::LogicalArray(expected));
144    }
145
146    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
147    #[test]
148    fn strcmp_char_array_row_compare() {
149        let chars = CharArray::new(vec!['c', 'a', 't', 'd', 'o', 'g'], 2, 3).unwrap();
150        let result =
151            strcmp_builtin(Value::CharArray(chars), Value::String("cat".into())).expect("cmp");
152        let expected = LogicalArray::new(vec![1, 0], vec![2, 1]).unwrap();
153        assert_eq!(result, Value::LogicalArray(expected));
154    }
155
156    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
157    #[test]
158    fn strcmp_char_array_to_char_array() {
159        let left = CharArray::new(vec!['a', 'b', 'c', 'd'], 2, 2).unwrap();
160        let right = CharArray::new(vec!['a', 'b', 'x', 'y'], 2, 2).unwrap();
161        let result =
162            strcmp_builtin(Value::CharArray(left), Value::CharArray(right)).expect("strcmp");
163        let expected = LogicalArray::new(vec![1, 0], vec![2, 1]).unwrap();
164        assert_eq!(result, Value::LogicalArray(expected));
165    }
166
167    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
168    #[test]
169    fn strcmp_cell_array_scalar() {
170        let cell = CellArray::new(
171            vec![
172                Value::from("apple"),
173                Value::from("pear"),
174                Value::from("grape"),
175            ],
176            1,
177            3,
178        )
179        .unwrap();
180        let result =
181            strcmp_builtin(Value::Cell(cell), Value::String("grape".into())).expect("strcmp");
182        let expected = LogicalArray::new(vec![0, 0, 1], vec![1, 3]).unwrap();
183        assert_eq!(result, Value::LogicalArray(expected));
184    }
185
186    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
187    #[test]
188    fn strcmp_cell_array_to_cell_array_broadcasts() {
189        let left = CellArray::new(vec![Value::from("red"), Value::from("blue")], 2, 1).unwrap();
190        let right = CellArray::new(vec![Value::from("red")], 1, 1).unwrap();
191        let result = strcmp_builtin(Value::Cell(left), Value::Cell(right)).expect("strcmp");
192        let expected = LogicalArray::new(vec![1, 0], vec![2, 1]).unwrap();
193        assert_eq!(result, Value::LogicalArray(expected));
194    }
195
196    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
197    #[test]
198    fn strcmp_string_array_multi_dimensional_broadcast() {
199        let left = StringArray::new(vec!["north".into(), "south".into()], vec![2, 1]).unwrap();
200        let right = StringArray::new(
201            vec!["north".into(), "east".into(), "south".into()],
202            vec![1, 3],
203        )
204        .unwrap();
205        let result =
206            strcmp_builtin(Value::StringArray(left), Value::StringArray(right)).expect("strcmp");
207        let expected = LogicalArray::new(vec![1, 0, 0, 0, 0, 1], vec![2, 3]).unwrap();
208        assert_eq!(result, Value::LogicalArray(expected));
209    }
210
211    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
212    #[test]
213    fn strcmp_char_array_trailing_space_is_not_equal() {
214        let chars = CharArray::new(vec!['c', 'a', 't', ' '], 1, 4).unwrap();
215        let result =
216            strcmp_builtin(Value::CharArray(chars), Value::String("cat".into())).expect("strcmp");
217        assert_eq!(result, Value::Bool(false));
218    }
219
220    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
221    #[test]
222    fn strcmp_char_array_empty_rows_returns_empty() {
223        let chars = CharArray::new(Vec::new(), 0, 0).unwrap();
224        let result = strcmp_builtin(Value::CharArray(chars), Value::String("anything".into()))
225            .expect("strcmp");
226        match result {
227            Value::LogicalArray(array) => {
228                assert_eq!(array.shape, vec![0, 1]);
229                assert!(array.data.is_empty());
230            }
231            other => panic!("expected empty logical array, got {other:?}"),
232        }
233    }
234
235    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
236    #[test]
237    fn strcmp_missing_strings_compare_false() {
238        let strings = StringArray::new(vec!["<missing>".into()], vec![1, 1]).unwrap();
239        let result = strcmp_builtin(
240            Value::StringArray(strings.clone()),
241            Value::StringArray(strings),
242        )
243        .expect("strcmp");
244        assert_eq!(result, Value::Bool(false));
245    }
246
247    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
248    #[test]
249    fn strcmp_missing_string_false() {
250        let array = StringArray::new(vec!["alpha".into(), "<missing>".into()], vec![1, 2]).unwrap();
251        let result =
252            strcmp_builtin(Value::StringArray(array), Value::String("alpha".into())).expect("cmp");
253        let expected = LogicalArray::new(vec![1, 0], vec![1, 2]).unwrap();
254        assert_eq!(result, Value::LogicalArray(expected));
255    }
256
257    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
258    #[test]
259    fn strcmp_size_mismatch_error() {
260        let left = StringArray::new(vec!["a".into(), "b".into()], vec![2, 1]).unwrap();
261        let right = StringArray::new(vec!["a".into(), "b".into(), "c".into()], vec![3, 1]).unwrap();
262        let err = error_message(
263            strcmp_builtin(Value::StringArray(left), Value::StringArray(right))
264                .expect_err("size mismatch"),
265        );
266        assert!(err.contains("size mismatch"));
267    }
268
269    #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
270    #[test]
271    fn strcmp_invalid_argument_type() {
272        let err = error_message(
273            strcmp_builtin(Value::Num(1.0), Value::String("a".into())).expect_err("invalid type"),
274        );
275        assert!(err.contains("first argument must be text"));
276    }
277
278    #[test]
279    fn strcmp_type_is_logical_match() {
280        assert_eq!(
281            logical_text_match_type(
282                &[Type::String, Type::String],
283                &ResolveContext::new(Vec::new()),
284            ),
285            Type::Bool
286        );
287    }
288}