Use when organizing functions within a Go file, formatting function signatures, designing return values, or following Printf-style naming conventions. Also use when a user is adding or refactoring any Go function, even if they don't mention function design or signature formatting. Does not cover fun

Go Function Design Resource Routing references/SIGNATURES.md Read when designing parameters, return values, named results, or signature readability. references/PRINTF STRINGER.md Read when using fmt verbs, Stringer, GoStringer, Formatter, or Printf style function naming. When this skill does NOT apply : For functional options constructors ( WithTimeout , WithLogger ), see [go functional options](../go functional options/SKILL.md). For error return conventions, see [go error handling](../go error handling/SKILL.md). For naming functions and methods, see [go naming](../go naming/SKILL.md). Function Grouping and Ordering Organize functions in a file by these rules: 1. Functions sorted in rough call order 2. Functions grouped by receiver 3. Exported functions appear first, after struct / const / var definitions 4. NewXxx / newXxx constructors appear right after the type definition 5. Plain utility functions appear toward the end of the file Function Signatures Keep the signature on a single line when possible. When it must wrap, put all arguments on their own lines with a trailing comma: Add / name / comments for ambiguous arguments, or better yet, replace naked bool parameters with custom types. Pointers to Interfaces You almost never need a pointer to an interface. Pass interfaces as values — the underlying data can still be a pointer. Printf and Stringer Printf style Function Names Functions that accept a format string should end in f for go vet support. Declare format strings as const when used outside Printf calls. Prefer %q over %s with manual quoting when formatting strings for logging or error messages — it safely escapes special characters and wraps in quotes: See go functional options when designing a constructor with 3+ optional parameters. Quick Reference Topic Rule File ordering Type constructor exported unexported utils Signature wrapping All args on own lines with trailing comma Naked parameters Add / name / comments or use custom types Pointers to interfaces Almost never needed; pass interfaces by value Printf function names End with f for go vet support Related Skills Error returns : See [go error handling](../go error handling/SKILL.md) when designing error return patterns or wrapping errors in multi return functions Naming conventions : See [go naming](../go naming/SKILL.md) when naming functions, methods, or choosing getter/setter patterns Functional options : See [go functional options](../go functional options/SKILL.md) when designing a constructor with 3+ optional parameters Formatting principles : See [go style core](../go style core/SKILL.md) when deciding line length, naked returns, or signature formatting

go-functions