Crate choir_merge 

Merge-strategy pipeline seam (DECISIONS.md D4/D19).

Ordered strategies, cheapest first; each maps (base, left, right) to Resolved or Conflict. LLM resolution and Mergiraf are just strategy slots, so widening or dropping them is configuration, not surgery. Mergiraf is GPLv3 (audited 2026-08-08): subprocess only, never linked (D4).

Examples

use choir_merge::{MergeOutcome, Pipeline};

let pipeline = Pipeline::default_v1();
// Only the right side changed, so the merge resolves trivially.
let result = pipeline.merge("a\n", "a\n", "a\nb\n");
assert_eq!(result.strategy, "trivial");
match result.outcome {
    MergeOutcome::Resolved(text) => assert_eq!(text, "a\nb\n"),
    _ => unreachable!(),
}

Where this sits

docs/architecture.md is the map of the whole workspace. This crate is the merge-strategy pipeline (D4/D19), cheapest strategy first.

It depends on no other crate in this workspace.

Modules

safety

Merge-safety verdict: did a resolved merge stay inside what the author proposed? (internal/oak.md item 1.)

silent_revert

Falsification (c): how often does a landed merge remove work that neither side removed?

Structs

LineMerge

Line-based 3-way merge (diffy), the histogram/ORT analog in the plan.

MergirafMerge

Structured (AST) merge via the mergiraf binary, subprocess only (GPLv3). CLI verified against mergiraf 0.18.0: mergiraf merge <BASE> <LEFT> <RIGHT> -o <OUT>; language is detected from the input file extension.

Pipeline

Runs strategies in order; first Resolved wins. If none resolves, returns the last Conflict (first-class conflict, never a silent pick).

PipelineResult

A Pipeline verdict plus which strategy produced it.

TrivialMerge

Cheapest checks: unchanged sides and identical edits.

Enums

MergeOutcome

Result of one strategy’s attempt at a 3-way merge.

Traits

MergeStrategy

The strategy seam: one slot in the Pipeline.

Functions

normalized_diff

The position-independent content of a change: the deleted and inserted lines of its diff, with hunk positions and context stripped — the cheap analog of git patch-id --stable (DECISIONS.md D15: metadata, never a new merge substrate). Two authorings of the same edit on different bases — the change before and after the train rewrites or rebases it — normalize to the same string, which is what lets a queue or bridge recognize an already-landed change instead of re-merging it. It lives here because this crate already owns the diff dependency; callers hash the result.