Module ssh_config 

ssh_config(5) parser and resolver for Anvil.

Implements the subset of OpenSSH ssh_config directives required by Gitway PRD §5.8.1. Layered as:

• [lexer] — line-oriented tokenizer. Strips comments, joins continuation lines, splits on whitespace honoring quoted arguments, recognizes the keyword=value form. Also exposes argument-level helpers ([lexer::expand_tilde], [lexer::expand_env], [lexer::wildcard_match]) used by include resolution and the directive resolver.
• [parser] — groups token lines into Host blocks, handling implicit global directives (before the first Host) and the Match keyword.
• include — recursively resolves Include directives, with tilde/env expansion, glob matching on the final component, a 16-deep nesting limit, and cycle detection by canonicalized path.
• [matcher] — flattens parsed blocks to the directives that apply to a given host, honoring positive/negated patterns and case- insensitive comparison. Match blocks are silently skipped per PRD §12 Q1.
• [resolver] — public entry point. Composes the above into one resolve call returning a ResolvedSshConfig with first-wins precedence and per-directive provenance.

Match blocks are explicitly deferred to v1.1 per PRD §12 Q1; they are recognized at parse time so directive grouping stays correct, but never match a host.

Only the items re-exported below are part of the crate’s public API; the sub-modules themselves are crate-private building blocks.

Structs

AlgList

A list of algorithm names from a ssh_config directive (HostKeyAlgorithms, KexAlgorithms, Ciphers, MACs).

DirectiveSource

Provenance for one resolved directive — which file and line it came from. Used by the gitway diag line (NFR-24) and gitway config show to attribute each value back to its source.

ResolvedSshConfig

Fully-resolved ssh_config for one host.

SshConfigPaths

Locations of the ssh_config files to read during a resolve call.

Enums

StrictHostKeyChecking

StrictHostKeyChecking directive value.

Functions

resolve

Resolves the effective ssh_config for host against the files listed in paths.