+mkCoreSel :: [Id] -- The tuple args
+ -> Id -- The selected one
+ -> Id -- A variable of the same type as the scrutinee
+ -> CoreExpr -- Scrutinee
+ -> CoreExpr
+-- mkCoreSel [x,y,z] x v e
+-- ===> case e of v { (x,y,z) -> x
+mkCoreSel [var] should_be_the_same_var scrut_var scrut
+ = ASSERT(var == should_be_the_same_var)
+ scrut
+
+mkCoreSel vars the_var scrut_var scrut
+ = ASSERT( notNull vars )
+ Case scrut scrut_var
+ [(DataAlt (tupleCon Boxed (length vars)), vars, Var the_var)]