reasoning_parser/parsers/
cohere_cmd.rs

1//! Cohere Command model reasoning parser.
2//!
3//! Parses thinking blocks from `<|START_THINKING|>...<|END_THINKING|>`.
4//! Supports CMD3 and CMD4 format.
5
6use crate::{
7    parsers::BaseReasoningParser,
8    traits::{ParseError, ParserConfig, ParserResult, ReasoningParser},
9};
10
11/// Cohere Command model reasoning parser.
12///
13/// Handles `<|START_THINKING|>` and `<|END_THINKING|>` tokens.
14/// Unlike DeepSeek-R1, Cohere requires explicit start token (initial_in_reasoning=false).
15pub struct CohereCmdParser {
16    base: BaseReasoningParser,
17}
18
19impl CohereCmdParser {
20    /// Create a new Cohere Command parser.
21    pub fn new() -> Self {
22        let config = ParserConfig {
23            think_start_token: "<|START_THINKING|>".to_string(),
24            think_end_token: "<|END_THINKING|>".to_string(),
25            stream_reasoning: true,
26            max_buffer_size: 65536,
27            initial_in_reasoning: false, // Requires explicit start token
28        };
29
30        Self {
31            base: BaseReasoningParser::new(config).with_model_type("cohere_cmd".to_string()),
32        }
33    }
34}
35
36impl Default for CohereCmdParser {
37    fn default() -> Self {
38        Self::new()
39    }
40}
41
42impl ReasoningParser for CohereCmdParser {
43    fn detect_and_parse_reasoning(&mut self, text: &str) -> Result<ParserResult, ParseError> {
44        self.base.detect_and_parse_reasoning(text)
45    }
46
47    fn parse_reasoning_streaming_incremental(
48        &mut self,
49        text: &str,
50    ) -> Result<ParserResult, ParseError> {
51        self.base.parse_reasoning_streaming_incremental(text)
52    }
53
54    fn reset(&mut self) {
55        self.base.reset()
56    }
57
58    fn model_type(&self) -> &str {
59        self.base.model_type()
60    }
61
62    fn is_in_reasoning(&self) -> bool {
63        self.base.is_in_reasoning()
64    }
65}
66
67#[cfg(test)]
68mod tests {
69    use super::*;
70
71    #[test]
72    fn test_cohere_cmd_no_reasoning() {
73        let mut parser = CohereCmdParser::new();
74
75        // Without thinking tags, text should be returned as normal
76        let result = parser
77            .detect_and_parse_reasoning("This is a normal response.")
78            .unwrap();
79        assert_eq!(result.normal_text, "This is a normal response.");
80        assert_eq!(result.reasoning_text, "");
81    }
82
83    #[test]
84    fn test_cohere_cmd_with_thinking() {
85        let mut parser = CohereCmdParser::new();
86
87        let result = parser
88            .detect_and_parse_reasoning(
89                "<|START_THINKING|>Let me analyze this step by step.<|END_THINKING|>The answer is 42.",
90            )
91            .unwrap();
92        assert_eq!(result.normal_text, "The answer is 42.");
93        assert_eq!(result.reasoning_text, "Let me analyze this step by step.");
94    }
95
96    #[test]
97    fn test_cohere_cmd_truncated_thinking() {
98        let mut parser = CohereCmdParser::new();
99
100        // Thinking block without end token (truncated)
101        let result = parser
102            .detect_and_parse_reasoning("<|START_THINKING|>Analyzing the problem...")
103            .unwrap();
104        assert_eq!(result.normal_text, "");
105        assert_eq!(result.reasoning_text, "Analyzing the problem...");
106    }
107
108    #[test]
109    fn test_cohere_cmd_streaming() {
110        let mut parser = CohereCmdParser::new();
111
112        // First chunk - start of thinking
113        let result1 = parser
114            .parse_reasoning_streaming_incremental("<|START_THINKING|>Step 1: ")
115            .unwrap();
116        assert_eq!(result1.reasoning_text, "Step 1: ");
117        assert_eq!(result1.normal_text, "");
118
119        // Second chunk - continue thinking
120        let result2 = parser
121            .parse_reasoning_streaming_incremental("Analyze inputs. ")
122            .unwrap();
123        assert_eq!(result2.reasoning_text, "Analyze inputs. ");
124        assert_eq!(result2.normal_text, "");
125
126        // Third chunk - end thinking and normal text
127        let result3 = parser
128            .parse_reasoning_streaming_incremental(
129                "Step 2: Check.<|END_THINKING|>Here's the answer.",
130            )
131            .unwrap();
132        assert_eq!(result3.reasoning_text, "Step 2: Check.");
133        assert_eq!(result3.normal_text, "Here's the answer.");
134    }
135
136    #[test]
137    fn test_cohere_cmd_streaming_partial_token() {
138        let mut parser = CohereCmdParser::new();
139
140        // Partial start token
141        let result1 = parser
142            .parse_reasoning_streaming_incremental("<|START_")
143            .unwrap();
144        assert_eq!(result1.reasoning_text, "");
145        assert_eq!(result1.normal_text, "");
146
147        // Complete the start token
148        let result2 = parser
149            .parse_reasoning_streaming_incremental("THINKING|>reasoning")
150            .unwrap();
151        assert_eq!(result2.reasoning_text, "reasoning");
152        assert_eq!(result2.normal_text, "");
153    }
154
155    #[test]
156    fn test_cohere_cmd_reset() {
157        let mut parser = CohereCmdParser::new();
158
159        // Process some text
160        parser
161            .parse_reasoning_streaming_incremental("<|START_THINKING|>thinking<|END_THINKING|>done")
162            .unwrap();
163
164        // Reset
165        parser.reset();
166        assert!(!parser.is_in_reasoning());
167
168        // Should work fresh again
169        let result = parser
170            .detect_and_parse_reasoning("<|START_THINKING|>new<|END_THINKING|>text")
171            .unwrap();
172        assert_eq!(result.reasoning_text, "new");
173        assert_eq!(result.normal_text, "text");
174    }
175
176    #[test]
177    fn test_model_type() {
178        let parser = CohereCmdParser::new();
179        assert_eq!(parser.model_type(), "cohere_cmd");
180    }
181
182    #[test]
183    fn test_cohere_full_response_format() {
184        let mut parser = CohereCmdParser::new();
185
186        // Simulate full Cohere response with thinking and response markers
187        let input = r#"<|START_THINKING|>
188Let me analyze this step by step.
1891. First, I'll consider the question.
1902. Then, I'll formulate a response.
191<|END_THINKING|>
192<|START_RESPONSE|>The answer is 42.<|END_RESPONSE|>"#;
193
194        let result = parser.detect_and_parse_reasoning(input).unwrap();
195        assert!(result.reasoning_text.contains("step by step"));
196        // Note: Response markers are passed through - cleaned by tool_parser or response processor
197        assert!(result.normal_text.contains("START_RESPONSE"));
198    }
199
200    #[test]
201    fn test_cohere_cmd_empty_thinking() {
202        let mut parser = CohereCmdParser::new();
203
204        let result = parser
205            .detect_and_parse_reasoning("<|START_THINKING|><|END_THINKING|>The answer.")
206            .unwrap();
207        assert_eq!(result.normal_text, "The answer.");
208        assert_eq!(result.reasoning_text, "");
209    }
210
211    #[test]
212    fn test_cohere_cmd_unicode_in_thinking() {
213        let mut parser = CohereCmdParser::new();
214
215        let result = parser
216            .detect_and_parse_reasoning(
217                "<|START_THINKING|>分析这个问题 🤔 emoji test<|END_THINKING|>答案是42。",
218            )
219            .unwrap();
220        assert_eq!(result.reasoning_text, "分析这个问题 🤔 emoji test");
221        assert_eq!(result.normal_text, "答案是42。");
222    }
223
224    #[test]
225    fn test_cohere_cmd_angle_brackets_in_thinking() {
226        let mut parser = CohereCmdParser::new();
227
228        // Angle brackets that don't match tokens should pass through
229        let result = parser
230            .detect_and_parse_reasoning(
231                "<|START_THINKING|>check if x < 10 and y > 5<|END_THINKING|>result",
232            )
233            .unwrap();
234        assert_eq!(result.reasoning_text, "check if x < 10 and y > 5");
235        assert_eq!(result.normal_text, "result");
236    }
237
238    #[test]
239    fn test_cohere_cmd_whitespace_only_thinking() {
240        let mut parser = CohereCmdParser::new();
241
242        let result = parser
243            .detect_and_parse_reasoning("<|START_THINKING|>   \n\t  <|END_THINKING|>answer")
244            .unwrap();
245        // BaseReasoningParser trims reasoning text
246        assert_eq!(result.reasoning_text, "");
247        assert_eq!(result.normal_text, "answer");
248    }
249}
reasoning_parser/parsers/cohere_cmd.rs

reasoning_parser/parsers/
cohere_cmd.rs
