format_prompt.rs

  1use crate::{
  2    FormatPromptArgs, PredictionProvider,
  3    example::{ActualCursor, Example, ExamplePrompt},
  4    headless::EpAppState,
  5    progress::{ExampleProgress, Step},
  6    retrieve_context::run_context_retrieval,
  7};
  8use anyhow::{Context as _, Result, anyhow};
  9use edit_prediction::{cursor_excerpt::editable_and_context_ranges_for_cursor_position, udiff};
 10use gpui::{AppContext, AsyncApp};
 11use language::{Buffer, OffsetRangeExt, Point};
 12use similar::DiffableStr;
 13use std::sync::Arc;
 14use std::{fmt::Write as _, ops::Range};
 15use zeta_prompt::ZetaFormat;
 16use zeta_prompt::format_zeta_prompt;
 17
 18pub async fn run_format_prompt(
 19    example: &mut Example,
 20    args: &FormatPromptArgs,
 21    app_state: Arc<EpAppState>,
 22    example_progress: &ExampleProgress,
 23    cx: AsyncApp,
 24) -> Result<()> {
 25    run_context_retrieval(example, app_state.clone(), example_progress, cx.clone()).await?;
 26
 27    let step_progress = example_progress.start(Step::FormatPrompt);
 28
 29    let prompt_inputs = example
 30        .prompt_inputs
 31        .as_ref()
 32        .context("prompt_inputs must be set after context retrieval")?;
 33
 34    let language = app_state
 35        .languages
 36        .load_language_for_file_path(&example.spec.cursor_path)
 37        .await
 38        .ok();
 39    let snapshot_fut = cx.update(|cx| {
 40        Buffer::build_snapshot(
 41            prompt_inputs.content.as_str().into(),
 42            language,
 43            Some(app_state.languages.clone()),
 44            cx,
 45        )
 46    });
 47    let cursor_point = Point::new(prompt_inputs.cursor_row, prompt_inputs.cursor_column);
 48    let snapshot = cx.background_spawn(snapshot_fut).await;
 49
 50    match args.provider {
 51        PredictionProvider::Teacher(_) | PredictionProvider::TeacherNonBatching(_) => {
 52            step_progress.set_substatus("formatting teacher prompt");
 53
 54            let (editable_range, context_range) = editable_and_context_ranges_for_cursor_position(
 55                cursor_point,
 56                &snapshot,
 57                edit_prediction::zeta2::max_editable_tokens(ZetaFormat::default()),
 58                edit_prediction::zeta2::MAX_CONTEXT_TOKENS,
 59            );
 60            let editable_range = editable_range.to_offset(&snapshot);
 61            let context_range = context_range.to_offset(&snapshot);
 62
 63            let prompt = TeacherPrompt::format_prompt(example, editable_range, context_range);
 64            example.prompt = Some(ExamplePrompt {
 65                input: prompt,
 66                expected_output: String::new(),
 67                rejected_output: None,
 68                prefill: None,
 69                provider: args.provider,
 70            });
 71        }
 72        PredictionProvider::Zeta2(version) => {
 73            step_progress.set_substatus("formatting zeta2 prompt");
 74
 75            let (editable_range, context_range) = editable_and_context_ranges_for_cursor_position(
 76                cursor_point,
 77                &snapshot,
 78                edit_prediction::zeta2::max_editable_tokens(version),
 79                edit_prediction::zeta2::MAX_CONTEXT_TOKENS,
 80            );
 81            let editable_range = editable_range.to_offset(&snapshot);
 82            let context_range = context_range.to_offset(&snapshot);
 83
 84            let context_start = context_range.start;
 85            let cursor_offset_in_excerpt = prompt_inputs.cursor_offset - context_start;
 86            let editable_range_in_excerpt =
 87                (editable_range.start - context_start)..(editable_range.end - context_start);
 88            let input = zeta_prompt::ZetaPromptInput {
 89                cursor_path: example.spec.cursor_path.clone(),
 90                cursor_excerpt: prompt_inputs.content[context_range].to_string().into(),
 91                editable_range_in_excerpt,
 92                cursor_offset_in_excerpt,
 93                excerpt_start_row: prompt_inputs.excerpt_start_row,
 94                events: prompt_inputs.edit_history.clone(),
 95                related_files: prompt_inputs.related_files.clone().unwrap_or_default(),
 96            };
 97            let prompt = format_zeta_prompt(&input, version);
 98            let prefill = zeta_prompt::get_prefill(&input, version);
 99            let (expected_patch, expected_cursor_offset) = example
100                .spec
101                .expected_patches_with_cursor_positions()
102                .into_iter()
103                .next()
104                .context("expected patches is empty")?;
105            let expected_output =
106                zeta2_output_for_patch(&input, &expected_patch, expected_cursor_offset, version)?;
107            let rejected_output = example
108                .spec
109                .rejected_patch
110                .as_ref()
111                .and_then(|patch| zeta2_output_for_patch(&input, patch, None, version).ok());
112
113            example.prompt = Some(ExamplePrompt {
114                input: prompt,
115                expected_output,
116                rejected_output,
117                provider: args.provider,
118                prefill: Some(prefill),
119            });
120        }
121        _ => {
122            panic!("Cannot format prompt for {:?}", args.provider);
123        }
124    };
125    Ok(())
126}
127
128pub fn zeta2_output_for_patch(
129    input: &zeta_prompt::ZetaPromptInput,
130    patch: &str,
131    cursor_offset: Option<usize>,
132    version: ZetaFormat,
133) -> Result<String> {
134    let mut old_editable_region =
135        input.cursor_excerpt[input.editable_range_in_excerpt.clone()].to_string();
136
137    if !old_editable_region.ends_with_newline() {
138        old_editable_region.push('\n');
139    }
140
141    let (mut result, first_hunk_offset) =
142        udiff::apply_diff_to_string_with_hunk_offset(patch, &old_editable_region).with_context(
143            || {
144                format!(
145                    "Patch:\n```\n{}```\n\nEditable region:\n```\n{}```",
146                    patch, old_editable_region
147                )
148            },
149        )?;
150
151    if let Some(cursor_offset) = cursor_offset {
152        // The cursor_offset is relative to the start of the hunk's new text (context + additions).
153        // We need to add where the hunk context matched in the editable region to compute
154        // the actual cursor position in the result.
155        let hunk_start = first_hunk_offset.unwrap_or(0);
156        let offset = (hunk_start + cursor_offset).min(result.len());
157        result.insert_str(offset, zeta_prompt::CURSOR_MARKER);
158    }
159
160    match version {
161        ZetaFormat::V0120GitMergeMarkers
162        | ZetaFormat::V0131GitMergeMarkersPrefix
163        | ZetaFormat::V0211SeedCoder => {
164            if !result.ends_with('\n') {
165                result.push('\n');
166            }
167            result.push_str(zeta_prompt::v0120_git_merge_markers::END_MARKER);
168        }
169        _ => (),
170    }
171
172    Ok(result)
173}
174
175pub struct TeacherPrompt;
176
177impl TeacherPrompt {
178    pub(crate) const EDITABLE_REGION_START: &str = "<|editable_region_start|>\n";
179    pub(crate) const EDITABLE_REGION_END: &str = "\n<|editable_region_end|>";
180    pub(crate) const USER_CURSOR_MARKER: &str = "<|user_cursor|>";
181    pub(crate) const NO_EDITS: &str = "NO_EDITS";
182
183    /// Truncate edit history to this number of last lines
184    const MAX_HISTORY_LINES: usize = 128;
185
186    pub fn format_prompt(
187        example: &Example,
188        editable_range: Range<usize>,
189        context_range: Range<usize>,
190    ) -> String {
191        let edit_history = Self::format_edit_history(&example.spec.edit_history);
192        let context = Self::format_context(example);
193        let cursor_excerpt = Self::format_cursor_excerpt(example, editable_range, context_range);
194
195        let prompt_template = crate::prompt_assets::get_prompt("teacher.md");
196        let prompt = prompt_template
197            .replace("{{context}}", &context)
198            .replace("{{edit_history}}", &edit_history)
199            .replace("{{cursor_excerpt}}", &cursor_excerpt);
200
201        prompt
202    }
203
204    pub fn parse(example: &Example, response: &str) -> Result<(String, Option<ActualCursor>)> {
205        // Extract updated (new) editable region from the model response.
206        // The model may include editable region markers in its output, so we need to strip them.
207        let new_editable_region = extract_last_codeblock(response);
208
209        // Check if the model indicated no edits are needed
210        if new_editable_region.trim() == Self::NO_EDITS {
211            return Ok((String::new(), None));
212        }
213
214        let new_editable_region = Self::extract_editable_region(&new_editable_region)?;
215        let cursor_offset = new_editable_region.find(Self::USER_CURSOR_MARKER);
216        let mut new_editable_region = new_editable_region.replace(Self::USER_CURSOR_MARKER, "");
217        let old_editable_region = Self::extract_editable_region(
218            &example
219                .prompt
220                .as_ref()
221                .context("example prompt missing")?
222                .input,
223        )?
224        .replace(Self::USER_CURSOR_MARKER, "");
225
226        let prompt_inputs = example
227            .prompt_inputs
228            .as_ref()
229            .context("example is missing prompt inputs")?;
230
231        // Normalize leading newlines: if old starts with newline but new doesn't,
232        // prepend newline to new to preserve whitespace structure.
233        // This handles the case where the model drops the leading blank line.
234        if old_editable_region.starts_with('\n') && !new_editable_region.starts_with('\n') {
235            new_editable_region.insert(0, '\n');
236        }
237
238        let (editable_region_offset, _) = prompt_inputs
239            .content
240            .match_indices(&old_editable_region)
241            .min_by_key(|(index, _)| index.abs_diff(prompt_inputs.cursor_offset))
242            .context("editable region not found in prompt content")?;
243        let editable_region_start_line = prompt_inputs.content[..editable_region_offset]
244            .matches('\n')
245            .count();
246
247        // Use full context so cursor offset (relative to editable region start) aligns with diff content
248        let editable_region_lines = old_editable_region.lines().count() as u32;
249        let diff = language::unified_diff_with_context(
250            &old_editable_region,
251            &new_editable_region,
252            editable_region_start_line as u32,
253            editable_region_start_line as u32,
254            editable_region_lines,
255        );
256
257        let diff = indoc::formatdoc! {"
258            --- a/{path}
259            +++ b/{path}
260            {diff}",
261            path = example.spec.cursor_path.to_string_lossy(),
262            diff = diff,
263        };
264
265        let actual_cursor = cursor_offset.map(|editable_region_cursor_offset| {
266            ActualCursor::from_editable_region(
267                &example.spec.cursor_path,
268                editable_region_cursor_offset,
269                &new_editable_region,
270                &prompt_inputs.content,
271                editable_region_offset,
272                editable_region_start_line,
273            )
274        });
275
276        Ok((diff, actual_cursor))
277    }
278
279    fn format_edit_history(edit_history: &str) -> String {
280        // Strip comments ("garbage lines") from edit history
281        let lines = edit_history
282            .lines()
283            .filter(|&s| Self::is_udiff_content_line(s))
284            .collect::<Vec<_>>();
285
286        let history_lines = if lines.len() > Self::MAX_HISTORY_LINES {
287            &lines[lines.len() - Self::MAX_HISTORY_LINES..]
288        } else {
289            &lines
290        };
291
292        if history_lines.is_empty() {
293            return "(No edit history)".to_string();
294        }
295
296        history_lines.join("\n")
297    }
298
299    pub fn format_context(example: &Example) -> String {
300        let related_files = example
301            .prompt_inputs
302            .as_ref()
303            .and_then(|pi| pi.related_files.as_ref());
304
305        let Some(related_files) = related_files else {
306            return "(No context)".to_string();
307        };
308
309        if related_files.is_empty() {
310            return "(No context)".to_string();
311        }
312
313        let mut prompt = String::new();
314        for file in related_files {
315            let path_str = file.path.to_string_lossy();
316            writeln!(&mut prompt, "`````{path_str}").ok();
317
318            let mut prev_row = 0;
319            for excerpt in &file.excerpts {
320                if excerpt.row_range.start > prev_row {
321                    prompt.push_str("\n");
322                }
323                prompt.push_str(&excerpt.text);
324                prompt.push('\n');
325                prev_row = excerpt.row_range.end;
326            }
327            if prev_row < file.max_row {
328                prompt.push_str("\n");
329            }
330            prompt.push_str("\n`````\n");
331        }
332
333        prompt
334    }
335
336    fn format_cursor_excerpt(
337        example: &Example,
338        editable_range: Range<usize>,
339        context_range: Range<usize>,
340    ) -> String {
341        let mut result = String::new();
342
343        let prompt_inputs = example.prompt_inputs.as_ref().unwrap();
344
345        let path_str = example.spec.cursor_path.to_string_lossy();
346        result.push_str(&format!("`````{path_str}\n"));
347        result.push_str(&prompt_inputs.content[context_range.start..editable_range.start]);
348        result.push_str(Self::EDITABLE_REGION_START);
349        result.push_str(&prompt_inputs.content[editable_range.start..prompt_inputs.cursor_offset]);
350        result.push_str(Self::USER_CURSOR_MARKER);
351        result.push_str(&prompt_inputs.content[prompt_inputs.cursor_offset..editable_range.end]);
352        result.push_str(Self::EDITABLE_REGION_END);
353        result.push_str(&prompt_inputs.content[editable_range.end..context_range.end]);
354        result.push_str("\n`````");
355
356        result
357    }
358
359    pub fn extract_editable_region(text: &str) -> Result<String> {
360        let start = text
361            .rfind(Self::EDITABLE_REGION_START)
362            .map_or(0, |pos| pos + Self::EDITABLE_REGION_START.len());
363        let end = text.rfind(Self::EDITABLE_REGION_END).unwrap_or(text.len());
364
365        if start >= end {
366            return Err(anyhow!("Invalid editable region markers"));
367        }
368
369        let region = &text[start..end];
370        Ok(region.strip_suffix('\n').unwrap_or(region).to_string())
371    }
372
373    fn is_udiff_content_line(s: &str) -> bool {
374        s.starts_with("-")
375            || s.starts_with("+")
376            || s.starts_with(" ")
377            || s.starts_with("---")
378            || s.starts_with("+++")
379            || s.starts_with("@@")
380    }
381}
382
383/// Extract the cursor excerpt from an example.
384/// First tries to extract from an existing prompt, then falls back to constructing from prompt_inputs.
385pub fn extract_cursor_excerpt_from_example(example: &Example) -> Option<String> {
386    // If we have the original prompt, extract the cursor excerpt from it
387    if let Some(prompt) = &example.prompt {
388        // Find "# 3. Current File" section and extract the content
389        if let Some(start) = prompt.input.find("# 3. Current File") {
390            let content_start = prompt.input[start..].find('`').map(|i| start + i)?;
391            let backtick_count = prompt.input[content_start..]
392                .chars()
393                .take_while(|&c| c == '`')
394                .count();
395            let content_start = content_start + backtick_count;
396
397            // Find the path line and skip it
398            let newline_pos = prompt.input[content_start..].find('\n')?;
399            let text_start = content_start + newline_pos + 1;
400
401            // Find the closing backticks
402            let closing_pattern = "`".repeat(backtick_count);
403            let text_end = prompt.input[text_start..].find(&closing_pattern)?;
404            let cursor_excerpt = &prompt.input[text_start..text_start + text_end];
405
406            let path_str = example.spec.cursor_path.to_string_lossy();
407            return Some(format!("`````{path_str}\n{cursor_excerpt}`````"));
408        }
409    }
410
411    // Fallback: construct from prompt_inputs if available
412    let prompt_inputs = example.prompt_inputs.as_ref()?;
413    let content = &prompt_inputs.content;
414    let cursor_offset = prompt_inputs.cursor_offset;
415
416    // Simple fallback: just show content around cursor with markers
417    let path_str = example.spec.cursor_path.to_string_lossy();
418    let mut result = format!("`````{path_str}\n");
419    result.push_str(TeacherPrompt::EDITABLE_REGION_START);
420    result.push_str(&content[..cursor_offset]);
421    result.push_str(TeacherPrompt::USER_CURSOR_MARKER);
422    result.push_str(&content[cursor_offset..]);
423    result.push_str(TeacherPrompt::EDITABLE_REGION_END);
424    result.push_str("\n`````");
425
426    Some(result)
427}
428
429pub(crate) fn extract_last_codeblock(text: &str) -> String {
430    let mut last_block = None;
431    let mut search_start = 0;
432
433    while let Some(start) = text[search_start..].find("```") {
434        let start = start + search_start;
435        let bytes = text.as_bytes();
436        let mut backtick_end = start;
437
438        while backtick_end < bytes.len() && bytes[backtick_end] == b'`' {
439            backtick_end += 1;
440        }
441
442        let backtick_count = backtick_end - start;
443        let closing_pattern = format!("\n{}", "`".repeat(backtick_count));
444
445        while backtick_end < bytes.len() && bytes[backtick_end] != b'\n' {
446            backtick_end += 1;
447        }
448
449        if let Some(end_pos) = text[backtick_end..].find(&closing_pattern) {
450            let code_block = &text[backtick_end + 1..backtick_end + end_pos + 1];
451            last_block = Some(code_block.to_string());
452            search_start = backtick_end + end_pos + closing_pattern.len();
453        } else {
454            break;
455        }
456    }
457
458    last_block.unwrap_or_else(|| text.to_string())
459}
460
461#[cfg(test)]
462mod tests {
463    use super::*;
464
465    #[test]
466    fn test_extract_last_code_block() {
467        let text = indoc::indoc! {"
468            Some thinking
469
470            ```
471            first block
472            ```
473
474            `````path='something' lines=1:2
475            last block
476            `````
477            "};
478        let last_block = extract_last_codeblock(text);
479        assert_eq!(last_block, "last block\n");
480    }
481
482    #[test]
483    fn test_extract_codeblock_with_nested_fences() {
484        let text = indoc::indoc! {"
485            `````
486            content with ``` inline
487            and ```python nested
488            more content
489            `````
490            "};
491        let last_block = extract_last_codeblock(text);
492        assert_eq!(
493            last_block,
494            "content with ``` inline\nand ```python nested\nmore content\n"
495        );
496    }
497
498    #[test]
499    fn test_extract_codeblock_ignores_inline_backticks() {
500        let text = indoc::indoc! {"
501            `````
502            here is some `code` with inline backticks
503            and here```more```stuff
504            `````
505            "};
506        let last_block = extract_last_codeblock(text);
507        assert_eq!(
508            last_block,
509            "here is some `code` with inline backticks\nand here```more```stuff\n"
510        );
511    }
512
513    #[test]
514    fn test_extract_editable_region() {
515        let text = indoc::indoc! {"
516            some lines
517            are
518            here
519            <|editable_region_start|>
520            one
521            two three
522
523            <|editable_region_end|>
524            more
525            lines here
526            "};
527        let parsed = TeacherPrompt::extract_editable_region(text).unwrap();
528        assert_eq!(
529            parsed,
530            indoc::indoc! {"
531            one
532            two three"}
533        );
534    }
535
536    #[test]
537    fn test_extract_last_codeblock_nested_bibtex() {
538        let text = indoc::indoc! {r#"
539            Looking at the edit history, I can see that a Citation section was just added.
540
541            `````
542            ## Collaborations
543            Our mission is to create a 4D generative model.
544
545            ## Citation
546
547            If you found Unique3D helpful, please cite our report:
548            ```bibtex
549            @misc{wu2024unique3d,
550                  title={Unique3D},
551            }
552            ```
553            `````
554            "#};
555        let last_block = extract_last_codeblock(text);
556        assert_eq!(
557            last_block,
558            indoc::indoc! {r#"
559            ## Collaborations
560            Our mission is to create a 4D generative model.
561
562            ## Citation
563
564            If you found Unique3D helpful, please cite our report:
565            ```bibtex
566            @misc{wu2024unique3d,
567                  title={Unique3D},
568            }
569            ```
570            "#}
571        );
572    }
573
574    #[test]
575    fn test_extract_editable_region_no_markers() {
576        let text = indoc::indoc! {"
577            one
578            two three"};
579        let parsed = TeacherPrompt::extract_editable_region(text).unwrap();
580        assert_eq!(
581            parsed,
582            indoc::indoc! {"
583            one
584            two three"}
585        );
586    }
587
588    #[test]
589    fn test_parse_no_edits_response() {
590        let response = indoc::indoc! {"
591            The code is already complete. There is no clear next edit to make.
592
593            `````
594            NO_EDITS
595            `````
596        "};
597        let codeblock = extract_last_codeblock(response);
598        assert_eq!(codeblock.trim(), TeacherPrompt::NO_EDITS);
599    }
600}