Type equality comparing both visible and invisible arguments, expanding synonyms and respecting multiplicities.

Compare types with respect to a (presumably) non-empty RnEnv2.

Type equality on lists of types, looking through type synonyms

Like pickyEqTypeVis, but returns a Bool for convenience

Just like tcEqType, but will return True for types of different kinds as long as their non-coercion structure is identical.

Check whether two TyConApps are the same; if the number of arguments are different, just checks the common prefix of arguments.

mayLookIdentical returns:

• An empty set if the two types are distinct unequal, and remain distinct even if we hide explicit kinds, runtime-reps, multiplicities.
• A non-empty set of invis_bits, if the two types might look equal, but are in fact distinct in the returned invis_bits.

See Note [mayLookIdentical], as well as Note [Showing invisible bits of types in error messages] in GHC.Tc.Errors.Ppr.

Make the sure the given invisible bits are displayed.

See Note [Showing invisible bits of types in error messages] in GHC.Tc.Errors.Ppr.

Something in a type which might be invisible.

Used to avoid reporting confusing errors to the user, like:

Couldn't match (a -> b) with (a -> b)

When in fact it is e.g. (a %1 -> b) vs (a %Many -> b), but the multiplicites have been suppressed.

See Note [Showing invisible bits of types in error messages] in GHC.Tc.Errors.Ppr.

A collection of InvisibleBits.

Do these denote the same level of visibility? Required arguments are visible, others are not. So this function equates Specified and Inferred. Used for printing.

Do these denote the same level of visibility? Required arguments are visible, others are not. So this function equates Specified and Inferred. Used for printing.