GHC.Core.TyCo.Compare

Type equality on source types. Does not look through newtypes, PredTypes or type families, but it does look through type synonyms. This first checks that the kinds of the types are equal and then checks whether the types are equal, ignoring casts and coercions. (The kind check is a recursive call, but since all kinds have type Type, there is no need to check the types of kinds.) See also Note [Non-trivial definitional equality] in GHC.Core.TyCo.Rep.

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

Type equality on lists of types, looking through type synonyms but not newtypes.

Compare two TyCons. See Note [nonDetCmpType nondeterminism]

Like pickyEqTypeVis, but returns a Bool for convenience

tcEqType implements typechecker equality It behaves just like eqType, but is implemented differently (for now)

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.

Returns True if the visible part of the types might look equal, even if they are really unequal (in the invisible bits)

This function is very similar to tc_eq_type but it is much more heuristic. Notably, it is always safe to return True, even with types that might (in truth) be unequal -- this affects error messages only (Originally there were one function with an extra flag, but the result was hard to understand.)

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.