Crate lean_ctx_patterns 

Deterministic shell-output compression patterns for LeanCTX | OSS.

Every pattern is a pure text transform: command line plus output in, compressed output (or None) out. Engine policy (protected commands, user filters, configuration) stays in the engine, which reaches this crate through its core::patterns facade. Engine-supplied facts enter through PatternEnv, so this crate never depends on the engine.

Modules

alembic

Alembic (SQLAlchemy migrations) output compression.

ansi

ANSI escape handling shared by the patterns and the engine compressor.

ansible

argocd

Argo CD (argocd app get/sync/list) output compression.

artisan

aws

bazel

buf

buf (protobuf tooling) output compression.

bun

cargo

clang

cmake

composer

cosign

Cosign (sigstore) output compression.

curl

dbt

dbt (data build tool) run/test/build output compression.

deno

deploy

Shared compressor for edge/PaaS deploy commands (vercel, fly, wrangler, skaffold, supabase).

deps_cmd

docker

dotnet

emspace

emspace CLI output.

env_filter

eslint

fd

find

flutter

flyway

Flyway (database migrations) output compression.

gem

RubyGems (gem) output compression.

gh

git

glab

golang

grep

grype

Grype vulnerability scanner output compression.

helm

jj

Jujutsu (jj) output compression.

json_crush

Deterministic JSON crusher — single source of truth for structural JSON compaction (#934, Headroom “Smart Crusher” port, GitLab #935).

json_schema

just

kubectl

linkerd

linkerd (linkerd check) output compression.

log_dedup

lossless_collapse

Strictly lossless repeat collapse for the governor’s R2 rule (governor design v1 §2 R2).

ls

make

maven

mise

mise (dev tool version manager) output compression.

mix

mlflow

MLflow CLI output compression.

mypy

mysql

next_build

ninja

npm

ollama

Ollama CLI output compression.

php

pip

playwright

pnpm

poetry

prettier

prisma

psql

pulumi

Pulumi (pulumi up/preview/destroy) output compression.

pytest

ruby

ruff

safety_needles

semgrep

Semgrep output compression.

spark

Apache Spark (spark-submit) log compression.

swift

swiftlint

SwiftLint output compression.

syft

Syft SBOM output compression.

sysinfo

systemd

template_collapse

Template collapse for the governor’s R4 rule.

terraform

test

tokens

trivy

Trivy vulnerability scanner output compression.

typescript

wget

zig

Structs

NoEnv

The neutral PatternEnv: no passthrough URLs.

Constants

PATTERN_ENGINE_VERSION

Pattern engine version. Bump when output format changes to maintain shell-output determinism guarantees. Consumers (proofs, benchmarks) can embed this version to detect pattern-breaking updates.

Traits

PatternEnv

Engine-supplied facts a pattern may need. The engine implements this from its configuration. NoEnv is the neutral environment for callers without one (tests, tools that run outside an engine).

Functions

compress_clean

The policy-free part of the engine’s compress_output: everything after the protected-command gate, the leading-cd unwrap, ANSI stripping and the user filter rules, which the engine applies first. clean_output is the ANSI-stripped output, output the raw one every result is measured against.

elision_marker

How an elided block announces itself (GH #1679).

has_vcs_owner

True for version-control commands whose output is authoritative under their own compressor and must not be reinterpreted by the generic log/test fallbacks (commit history is not application log output). emspace is owned the same way: its page bodies are page edit anchors and must stay exact.

inflates_tokens

True when compressed carries more tokens than the raw original — i.e. the transform inflated rather than compressed. Compared against the raw (pre-ANSI-strip) output so the guard matches the public compress_output invariant exactly: the returned text never tokenizes larger than its input.

pattern_count

Ordered prefix → compressor dispatch table (#660 CC reduction): first matching entry wins, mirroring the previous if c.starts_with(..) { return ...; } cascade exactly — including that a matched entry’s None is final, never falls through to a later entry. Registering a new CLI tool is now a one-line addition here instead of a new branch in try_specific_pattern. Number of registered shell-output patterns, for the docs drift check (#1896).

shorter_only

Some(compressed) only when it carries fewer tokens than original (ties broken by length), compared on whitespace-normalized text.

try_specific_pattern_with

Route cmd to its dedicated compressor: the first matching entry of the dispatch table wins, and a matched entry’s None is final.