v0.1.0

Added

• Candor.define(target, name, aliases:, via:, parameters:, body:) — fabricates a real method whose arity, parameters kinds and source_location are the body's. Bodies may be a block, a Proc, a Method or an UnboundMethod; a #call object or any body with a nil source_location (a curried proc, a C-defined method) raises TypeError. With via: every call routes to that interceptor, which reaches the body through Candor.body_name; without it the wrapper forwards straight to the body. A wrong-arity call or an unknown keyword raises ArgumentError at the wrapper, before the interceptor or the body runs. An unpassed optional is dropped from the forwarded arguments, so the body applies its own default.
• Candor::Signature — the low-level compiler, public on its own: a parameter shape, a call-site name and a source_location in, a dispatch lambda out. Renders off a parameter's kind, never its name, so end:, it, _1, **nil and destructuring parameters all wrap at full fidelity. Both call-site names are validated against a strict method-name pattern, and a malformed parameters shape raises ArgumentError rather than a SyntaxError from inside eval — including a shape whose entries are each legal but whose combination Ruby's parser rejects, which is compiled before the target is mutated so a rejected fabrication cannot destroy the method it was replacing.
• Dispatch allocates nothing for shapes up to Candor::Signature::KEYWORD_BRANCH_LIMIT (2) optional keywords; beyond it, exactly one Hash per call. Past the limit a body's keyrest is that Hash, so a **kw in the signature costs only the capture and re-splat Ruby charges any wrapper. Exact from Ruby 3.4: on earlier Rubies the VM charges a define_method-created method for arguments crossing into it, and both the wrapper and the body are ones. A call carrying no keyword allocates nothing on every supported Ruby.
• Fabrication is thread-safe through one global Monitor; call-time dispatch takes no lock and never needs one. Re-fabricating a name overwrites the wrapper and the body in place, so it is warning-free under ruby -w, leaves no orphaned body, and a concurrent caller sees the old method or the new one, never a NoMethodError. A frozen target, an unbindable Method/UnboundMethod body, a name under the reserved Candor::BODY_PREFIX, an uncallable via: and a malformed parameters: all raise before the target is touched.
• sig/ ships RBS for the public API: Candor.define, Candor.body_name, BODY_PREFIX, and Candor::Signature with KINDS and KEYWORD_BRANCH_LIMIT. Everything else is private_constant, which RBS cannot express and therefore does not declare.

Install: gem "candor" — Ruby >= 3.2, zero runtime dependencies.

https://rubygems.org/gems/candor/versions/0.1.0