ghc-8.4.2: The GHC API

Safe HaskellNone




data InferMode Source #

How should we choose which constraints to quantify over?



Apply the monomorphism restriction, never quantifying over any constraints


See Note [TcRnExprMode] in TcRnDriver, the :type +d case; this mode refuses to quantify over any defaultable constraint


Quantify over any constraint that satisfies TcType.pickQuantifiablePreds

Outputable InferMode # 
Instance details

Defined in TcSimplify

solveEqualities :: TcM a -> TcM a Source #

Type-check a thing that emits only equality constraints, then solve those constraints. Fails outright if there is trouble.

tcSubsumes :: TcSigmaType -> TcSigmaType -> TcM Bool Source #

Reports whether first type (ty_a) subsumes the second type (ty_b), discarding any errors. Subsumption here means that the ty_b can fit into the ty_a, i.e. `tcSubsumes a b == True` if b is a subtype of a. N.B.: Make sure that the types contain all the constraints contained in any associated implications.

tcCheckHoleFit :: Cts -> TcSigmaType -> TcSigmaType -> TcM Bool Source #

A tcSubsumes which takes into account relevant constraints, to fix trac #14273. Make sure that the constraints are cloned, since the simplifier may perform unification

runTcSDeriveds :: TcS a -> TcM a Source #

This variant of runTcS will keep solving, even when only Deriveds are left around. It also doesn't return any evidence, as callers won't need it.