ptrrecv

README

yze-go-ptrrecv

A yze analyzer (category immutability) enforcing the gomatic Go immutability standard: methods use value receivers, never pointer receivers, unless the receiver type transitively contains a field that cannot be copied (a sync primitive, sync/atomic type, bytes.Buffer, or strings.Builder).

Pointer receivers imply mutability — and on exported types that leaks into interface semantics and concurrency expectations. This analyzer flags every pointer-receiver method whose type holds no no-copy field.

The rule is intentionally narrow: only a transitively-uncopyable field justifies a pointer receiver. Mutation and interface-satisfaction are deliberately not carve-outs — that narrowness reflects the gomatic immutability preference. The no-copy walk recurses through nested structs and through array elements (an array stores its elements inline, so a no-copy element makes the array uncopyable), but not through slices, maps, channels, or pointers, which are references that leave the enclosing struct copyable.

• Rule: yze/ptrrecv
• No-copy types: 16 baked-in standard-library types, extensible at runtime via the -allow flag (comma-separated fully-qualified pkgpath.Name entries).
• Suggested fix: the diagnostic carries a "change to a value receiver" fix (deleting the receiver's *) only when the rewrite is provably behavior-preserving: the body never assigns through the receiver (including ++/--, index/field chains, and range assignment), never takes the address of the receiver or anything reachable through it, never calls a pointer-receiver method on the receiver, and never mentions the receiver bare (which would change its pointer-typed semantics). Since the yze driver applies fixes to packages loaded without test files, dropping the * is chosen because it only widens the method set — unseen callers keep compiling — and the mutation analysis guarantees no copy is silently mutated. When in doubt the diagnostic is reported without a fix.
• Binary: cmd/yze-go-ptrrecv runs it standalone (text/-json, and as a go vet -vettool).

Built on the go-yze framework.

Documentation

Overview

Package ptrrecv provides a go/analysis analyzer enforcing the gomatic Go immutability standard: methods use value receivers, never pointer receivers, unless the receiver type transitively contains a field that cannot be copied (a sync primitive, atomic, buffer, or builder).

Index

• Variables

Variables

var Analyzer = newAnalyzer()

Analyzer reports pointer-receiver methods on types that need no pointer.

var Registration = goyze.Registration{
	Name:       "ptrrecv",
	Categories: []goyze.Category{"immutability"},
	URL:        "https://docs.gomatic.dev/yze/ptrrecv",
	Analyzer:   Analyzer,
}

Registration declares this analyzer to the yze framework.