Tweak expression search heuristic

Search locals left to right, so that they are used as arguments in the
same order by default in recursive calls.

src/TTImp/Interactive/ExprSearch.idr

@@ -357,7 +357,10 @@ searchLocal : {auto c : Ref Ctxt Defs} ->
               Maybe RecData -> Core (List (Term vars))
 searchLocal fc rig opts env ty topty defining
     = do defs <- get Ctxt
-         searchLocalWith fc rig opts env (getAllEnv fc [] env)
+         -- Reverse the environment so we try the patterns left to right.
+         -- This heuristic is just so arguments appear the same order in
+         -- recursive calls
+         searchLocalWith fc rig opts env (reverse (getAllEnv fc [] env))
                          ty topty defining
 
 searchType : {auto c : Ref Ctxt Defs} ->

tests/idris2/interactive005/IEdit.idr

@@ -12,6 +12,8 @@ my_uncurry : (a -> b -> c) -> (a, b) -> c
 
 append : Vect n a -> Vect m a -> Vect (n + m) a
 
+lappend : (1 xs : List a) -> (1 ys : List a) -> List a
+
 zipWith : (a -> b -> c) -> Vect n a -> Vect n b -> Vect n c
 
 data Env : Vect n Type -> Type where

tests/idris2/interactive005/expected

@@ -4,6 +4,8 @@ Main> my_curry f x y = f (x, y)
 Main> my_uncurry f x = f (fst x) (snd x)
 Main> append [] ys = ys
 append (x :: xs) ys = x :: append xs ys
+Main> lappend [] ys = ys
+lappend (x :: xs) ys = x :: lappend xs ys
 Main> zipWith f [] ys = []
 zipWith f (x :: xs) (y :: ys) = f x y :: zipWith f xs ys
 Main> lookup Here (ECons x es) = x

tests/idris2/interactive005/input

@@ -2,7 +2,8 @@
 :gd 9 my_curry
 :gd 11 my_uncurry
 :gd 13 append
-:gd 15 zipWith
-:gd 27 lookup
+:gd 15 lappend
+:gd 17 zipWith
+:gd 29 lookup
 :t my_uncurry
 :q