GHC.Hs.Expr

Parenthesize an expression without token information

hsExprNeedsParens p e returns True if the expression e needs parentheses under precedence p.

Is there only one RHS in this list of matches?

Make a 'SyntaxExpr GhcRn' from an expression Used only in getMonadFailOp. See Note [Monad fail : Rebindable syntax, overloaded strings] in GHC.Rename.Expr

This is used for rebindable-syntax pieces that are too polymorphic for tcSyntaxOp (trS_fmap and the mzip in ParStmt)

parenthesizeHsExpr p e checks if hsExprNeedsParens p e is true, and if so, surrounds e with an HsPar. Otherwise, it simply returns e.

The RdrName for an unnamed hole ("_").

Applicative Argument

ApplicativeStmt represents an applicative expression built with <$> and <*>. It is generated by the renamer, and is desugared into the appropriate applicative expression by the desugarer, but it is intended to be invisible in error messages.

For full details, see Note [ApplicativeDo] in GHC.Rename.Expr

Command Syntax Table (for Arrow syntax)

Information about an implicit lift, discovered by the renamer See Note [Lifecycle of an untyped splice, and PendingRnSplice]

Information about a quasi-quoter, discovered by the renamer See Note [Lifecycle of an untyped splice, and PendingRnSplice]

Information about the parent of a record update:

• the parent type constructor or pattern synonym,

• the relevant con-likes,

• the field labels.

Information about a user-written splice, discovered by the renamer See Note [Lifecycle of an untyped splice, and PendingRnSplice]

HsWrap appears only in typechecker output

Pending Type-checker Splice See Note [Lifecycle of an untyped splice, and PendingRnSplice]

Post-Type checking Expression

PostTcExpr is an evidence expression attached to the syntax tree by the type checker (c.f. postTcType).

Post-Type checking Table

We use a PostTcTable where there are a bunch of pieces of evidence, more than is convenient to keep individually.

The function to use in rebindable syntax. See Note [NoSyntaxExpr].

An expression with wrappers, used for rebindable syntax

This should desugar to

syn_res_wrap $ syn_expr (syn_arg_wraps[0] arg0)
                        (syn_arg_wraps[1] arg1) ...

where the actual arguments come from elsewhere in the AST.

Finalizers produced by a splice with addModFinalizer

See Note [Delaying modFinalizers in untyped splices] in GHC.Rename.Splice. For how this is used.