diff --git a/2019/day7/day7.hs b/2019/day7/day7.hs
index 614bb04..047487e 100644
--- a/2019/day7/day7.hs
+++ b/2019/day7/day7.hs
@@ -52,22 +52,22 @@ getOpModes opvec = (op_dedup,parsed_modes)
           op_dedup = if L.last op == '0' then [L.head op] else op
 
 step :: TapeSection -> (TuringMachine, [Int], [Int]) -> (TuringMachine, OutAction, [Int], [Int])
-step opvec ((t,p),input,val)
-        | op=="1" = (tm_binop (+),Continue,input,val)
-        | op=="2" = (tm_binop (*),Continue,input,val)
-        | op=="3" = (new_tm t (L.head input),Continue,L.tail input,val)
-        | op=="4" = ((t,p),Output,input,V.last params:val)
-        | op=="5" = ((t, if params ! 0/=0 then params ! 1 else p),Continue,input,val)
-        | op=="6" = ((t, if params ! 0==0 then params ! 1 else p),Continue,input,val)
-        | op=="7" = (new_tm t (if (params ! 0)<(params ! 1)
+step opvec ((t,p),input,val) = case op of
+    "1" -> (tm_binop (+),Continue,input,val)
+    "2" -> (tm_binop (*),Continue,input,val)
+    "3" -> (new_tm t (L.head input),Continue,L.tail input,val)
+    "4" -> ((t,p),Output,input,V.last params:val)
+    "5" -> ((t, if params ! 0/=0 then params ! 1 else p),Continue,input,val)
+    "6" -> ((t, if params ! 0==0 then params ! 1 else p),Continue,input,val)
+    "7" -> (new_tm t (if (params ! 0)<(params ! 1)
                     then 1 else 0),Continue,input,val)
-        | op=="8" = (new_tm t (if (params ! 0)==(params ! 1)
+    "8" -> (new_tm t (if (params ! 0)==(params ! 1)
                     then 1 else 0),Continue,input,val)
-        | op=="99" = ((t,p),Halt,input,val)
-        where (op,m) = getOpModes opvec
-              params = paramChange m opvec t
-              tm_binop x = new_tm t ((params ! 0) `x` (params ! 1))
-              new_tm t x = (t // [(V.last opvec, x)],p)
+    "99" -> ((t,p),Halt,input,val)
+    where (op,m) = getOpModes opvec
+          params = paramChange m opvec t
+          tm_binop x = new_tm t ((params ! 0) `x` (params ! 1))
+          new_tm t x = (t // [(V.last opvec, x)],p)
 
 execSteps :: (TuringMachine, [Int], [Int], OutAction) -> (TuringMachine, [Int], [Int], OutAction)
 execSteps ((t,p),input,output,halt) =