GHC.SourceGen.Expr

This module provides combinators for constructing Haskell expressions.

Documentation

overLabel :: String -> HsExpr'

An overloaded label, as used with the OverloadedLabels extension.

#foo
=====
overLabel "foo"

let' :: [RawValBind] -> HsExpr' -> HsExpr'

case' :: HsExpr' -> [RawMatch] -> HsExpr'

lambda :: [Pat'] -> HsExpr' -> HsExpr'

lambdaCase :: [RawMatch] -> HsExpr'

if' :: HsExpr' -> HsExpr' -> HsExpr' -> HsExpr'

multiIf :: [GuardedExpr] -> HsExpr'

A MultiWayIf expression.

if | f x = "f"
   | g x = "g"
   | otherwise = "h"
=====
multiIf
    [ guardedStmt (var "f" @@ var "x") $ rhs (string "f")
    , guardedStmt (var "g" @@ var "x") $ rhs (string "g")
    , guardedStmt (var "otherwise") $ rhs (string "h")
    ]

do' :: [Stmt'] -> HsExpr'

A do-expression.

Individual statements may be constructed with <-- and/or stmt.

do
  x <- act
  return x
=====
do' [var "x" <-- var "act", stmt $ var "return" @@ var "x"]

(@::@) :: HsExpr' -> HsType' -> HsExpr'

A type constraint on an expression.

e :: t
=====
var "e" @::@ var "t"

tyApp :: HsExpr' -> HsType' -> HsExpr'

Explicit type application.

f @ Int
=====
var "f" @@ var "Int"