funcpkg

var src = `package example
func (receiver *Type) F1(a, b int, c bool)  () {
}

var f = func(a, b int, c bool) {
}


type I1 interface {
  M1()
  M2()(a int, b bool)
  I2
}

type I2 interface{}
`
problems.Clear()
rule := Rule{
	key: "func",
	Name: namepkg.Rule{
		MaxLen: 30, Style: "camelCase",
	},
	Size: sizeRule{
		MaxParams: 2, MaxResults: 1, MaxStatements: 30,
	},
}

w := walker.Parse("example.go", src)
w.Walk(func(isLocal bool, node ast.Node) {
	rule.Check(node, w.FileSet)
})
problems.Render()

Output:

+-----------------+-----------------------------------------------+----------------------+
|    position     |                    problem                    |         rule         |
+-----------------+-----------------------------------------------+----------------------+
| example.go:2:25 | func F1 params size: 3, limit: 2              | func.size.maxParams  |
| example.go:5:13 | literal func params size: 3, limit: 2         | func.size.maxParams  |
| example.go:11:7 | interface method M2 results size: 2, limit: 1 | func.size.maxResults |
+-----------------+-----------------------------------------------+----------------------+