Linters for Mathlib

In this file we define additional linters for mathlib, which concern the behaviour of the linted code, and not issues of code style or formatting.

Perhaps these should be moved to Batteries in the future.

def Batteries.Tactic.Lint.structureInType : Linter

Linter that checks whether a structure should be in Prop.

def Batteries.Tactic.Lint.deprecatedNoSince : Linter

Linter that check that all deprecated tags come with since dates.

dupNamespace linter

The dupNamespace linter produces a warning when a declaration contains the same namespace at least twice consecutively.

For instance, Nat.Nat.foo and One.two.two trigger a warning, while Nat.One.Nat does not.

opaque Mathlib.Linter.linter.dupNamespace : Lean.Option Bool

The dupNamespace linter is set on by default. Lean emits a warning on any declaration that contains the same namespace at least twice consecutively.

For instance, Nat.Nat.foo and One.two.two trigger a warning, while Nat.One.Nat does not.

Note. This linter will not detect duplication in namespaces of autogenerated declarations (other than the one whose declId is present in the source declaration).