format_prompt.rs

  1use crate::{
  2    PromptFormat,
  3    example::{Example, ExamplePrompt},
  4    headless::EpAppState,
  5    load_project::run_load_project,
  6    progress::{Progress, Step},
  7    retrieve_context::run_context_retrieval,
  8};
  9use anyhow::{Context as _, Result, ensure};
 10use edit_prediction::{
 11    EditPredictionStore,
 12    zeta2::{zeta2_output_for_patch, zeta2_prompt_input},
 13};
 14use gpui::AsyncApp;
 15use std::sync::Arc;
 16use zeta_prompt::format_zeta_prompt;
 17
 18pub async fn run_format_prompt(
 19    example: &mut Example,
 20    prompt_format: PromptFormat,
 21    app_state: Arc<EpAppState>,
 22    mut cx: AsyncApp,
 23) -> Result<()> {
 24    run_context_retrieval(example, app_state.clone(), cx.clone()).await?;
 25
 26    let _step_progress = Progress::global().start(Step::FormatPrompt, &example.spec.name);
 27
 28    match prompt_format {
 29        PromptFormat::Teacher => {
 30            let prompt = TeacherPrompt::format_prompt(example);
 31            example.prompt = Some(ExamplePrompt {
 32                input: prompt,
 33                expected_output: example
 34                    .spec
 35                    .expected_patches
 36                    .first()
 37                    .cloned()
 38                    .unwrap_or_default(),
 39                format: prompt_format,
 40            });
 41        }
 42        PromptFormat::Zeta2 => {
 43            run_load_project(example, app_state, cx.clone()).await?;
 44
 45            let ep_store = cx.update(|cx| {
 46                EditPredictionStore::try_global(cx).context("EditPredictionStore not initialized")
 47            })??;
 48
 49            let state = example.state.as_ref().context("state must be set")?;
 50            let snapshot = state.buffer.read_with(&cx, |buffer, _| buffer.snapshot())?;
 51            let project = state.project.clone();
 52            let (_, input) = ep_store.update(&mut cx, |ep_store, cx| {
 53                let events = ep_store
 54                    .edit_history_for_project(&project, cx)
 55                    .into_iter()
 56                    .map(|e| e.event)
 57                    .collect();
 58                anyhow::Ok(zeta2_prompt_input(
 59                    &snapshot,
 60                    example
 61                        .context
 62                        .as_ref()
 63                        .context("context must be set")?
 64                        .files
 65                        .clone(),
 66                    events,
 67                    example.spec.cursor_path.clone(),
 68                    example
 69                        .buffer
 70                        .as_ref()
 71                        .context("buffer must be set")?
 72                        .cursor_offset,
 73                ))
 74            })??;
 75            let prompt = format_zeta_prompt(&input);
 76            let expected_output = zeta2_output_for_patch(
 77                &input,
 78                &example
 79                    .spec
 80                    .expected_patches
 81                    .first()
 82                    .context("expected patches is empty")?
 83                    .clone(),
 84            )?;
 85            example.prompt = Some(ExamplePrompt {
 86                input: prompt,
 87                expected_output,
 88                format: prompt_format,
 89            });
 90        }
 91    };
 92    Ok(())
 93}
 94
 95pub struct TeacherPrompt;
 96
 97impl TeacherPrompt {
 98    const PROMPT: &str = include_str!("teacher.prompt.md");
 99    pub(crate) const EDITABLE_REGION_START: &str = "<|editable_region_start|>\n";
100    pub(crate) const EDITABLE_REGION_END: &str = "<|editable_region_end|>";
101    pub(crate) const USER_CURSOR_MARKER: &str = "<|user_cursor|>";
102
103    /// Truncate edit history to this number of last lines
104    const MAX_HISTORY_LINES: usize = 128;
105
106    pub fn format_prompt(example: &Example) -> String {
107        let edit_history = Self::format_edit_history(&example.spec.edit_history);
108        let context = Self::format_context(example);
109        let editable_region = Self::format_editable_region(example);
110
111        let prompt = Self::PROMPT
112            .replace("{{context}}", &context)
113            .replace("{{edit_history}}", &edit_history)
114            .replace("{{editable_region}}", &editable_region);
115
116        prompt
117    }
118
119    pub fn parse(example: &Example, response: &str) -> Result<String> {
120        // Ideally, we should always be able to find cursor position in the retrieved context.
121        // In reality, sometimes we don't find it for these reasons:
122        // 1. `example.cursor_position` contains _more_ context than included in the retrieved context
123        //    (can be fixed by getting cursor coordinates at the load_example stage)
124        // 2. Context retriever just didn't include cursor line.
125        //
126        // In that case, fallback to using `cursor_position` as excerpt.
127        let cursor_file = &example
128            .buffer
129            .as_ref()
130            .context("`buffer` should be filled in in the context collection step")?
131            .content;
132
133        // Extract updated (new) editable region from the model response
134        let new_editable_region = extract_last_codeblock(response);
135
136        // Reconstruct old editable region we sent to the model
137        let old_editable_region = Self::format_editable_region(example);
138        let old_editable_region = Self::extract_editable_region(&old_editable_region);
139        ensure!(
140            cursor_file.contains(&old_editable_region),
141            "Something's wrong: editable_region is not found in the cursor file"
142        );
143
144        // Apply editable region to a larger context and compute diff.
145        // This is needed to get a better context lines around the editable region
146        let edited_file = cursor_file.replace(&old_editable_region, &new_editable_region);
147        let diff = language::unified_diff(&cursor_file, &edited_file);
148
149        let diff = indoc::formatdoc! {"
150            --- a/{path}
151            +++ b/{path}
152            {diff}",
153            path = example.spec.cursor_path.to_string_lossy(),
154            diff = diff,
155        };
156
157        Ok(diff)
158    }
159
160    fn format_edit_history(edit_history: &str) -> String {
161        // Strip comments ("garbage lines") from edit history
162        let lines = edit_history
163            .lines()
164            .filter(|&s| Self::is_udiff_content_line(s))
165            .collect::<Vec<_>>();
166
167        let history_lines = if lines.len() > Self::MAX_HISTORY_LINES {
168            &lines[lines.len() - Self::MAX_HISTORY_LINES..]
169        } else {
170            &lines
171        };
172
173        if history_lines.is_empty() {
174            return "(No edit history)".to_string();
175        }
176
177        history_lines.join("\n")
178    }
179
180    fn format_context(example: &Example) -> String {
181        assert!(example.context.is_some(), "Missing context retriever step");
182
183        let mut prompt = String::new();
184        zeta_prompt::write_related_files(&mut prompt, &example.context.as_ref().unwrap().files);
185
186        prompt
187    }
188
189    fn format_editable_region(example: &Example) -> String {
190        let mut result = String::new();
191
192        let path_str = example.spec.cursor_path.to_string_lossy();
193        result.push_str(&format!("`````path=\"{path_str}\"\n"));
194        result.push_str(Self::EDITABLE_REGION_START);
195
196        // TODO: control number of lines around cursor
197        let (mut excerpt, offset) = example.spec.cursor_excerpt().unwrap();
198        excerpt.insert_str(offset, Self::USER_CURSOR_MARKER);
199        result.push_str(&excerpt);
200        if !result.ends_with('\n') {
201            result.push('\n');
202        }
203
204        result.push_str(Self::EDITABLE_REGION_END);
205        result.push_str("\n`````");
206
207        result
208    }
209
210    fn extract_editable_region(text: &str) -> String {
211        let start = text
212            .find(Self::EDITABLE_REGION_START)
213            .map_or(0, |pos| pos + Self::EDITABLE_REGION_START.len());
214        let end = text.find(Self::EDITABLE_REGION_END).unwrap_or(text.len());
215
216        let region = &text[start..end];
217
218        region.replace("<|user_cursor|>", "")
219    }
220
221    fn is_udiff_content_line(s: &str) -> bool {
222        s.starts_with("-")
223            || s.starts_with("+")
224            || s.starts_with(" ")
225            || s.starts_with("---")
226            || s.starts_with("+++")
227            || s.starts_with("@@")
228    }
229}
230
231fn extract_last_codeblock(text: &str) -> String {
232    let mut last_block = None;
233    let mut search_start = 0;
234
235    while let Some(start) = text[search_start..].find("```") {
236        let start = start + search_start;
237        let bytes = text.as_bytes();
238        let mut backtick_end = start;
239
240        while backtick_end < bytes.len() && bytes[backtick_end] == b'`' {
241            backtick_end += 1;
242        }
243
244        let backtick_count = backtick_end - start;
245        let closing_backticks = "`".repeat(backtick_count);
246
247        while backtick_end < bytes.len() && bytes[backtick_end] != b'\n' {
248            backtick_end += 1;
249        }
250
251        if let Some(end_pos) = text[backtick_end..].find(&closing_backticks) {
252            let code_block = &text[backtick_end + 1..backtick_end + end_pos];
253            last_block = Some(code_block.to_string());
254            search_start = backtick_end + end_pos + backtick_count;
255        } else {
256            break;
257        }
258    }
259
260    last_block.unwrap_or_else(|| text.to_string())
261}
262
263#[cfg(test)]
264mod tests {
265    use super::*;
266
267    #[test]
268    fn test_extract_last_code_block() {
269        let text = indoc::indoc! {"
270            Some thinking
271
272            ```
273            first block
274            ```
275
276            `````path='something' lines=1:2
277            last block
278            `````
279            "};
280        let last_block = extract_last_codeblock(text);
281        assert_eq!(last_block, "last block\n");
282    }
283
284    #[test]
285    fn test_extract_editable_region() {
286        let text = indoc::indoc! {"
287            some lines
288            are
289            here
290            <|editable_region_start|>
291            one
292            two three
293
294            <|editable_region_end|>
295            more
296            lines here
297            "};
298        let parsed = TeacherPrompt::extract_editable_region(text);
299        assert_eq!(
300            parsed,
301            indoc::indoc! {"
302            one
303            two three
304
305            "}
306        );
307    }
308}