Add :undef

1 files changed, 15 insertions, 6 deletions

diff --git a/iclean.icl b/iclean.icl
index 4daba82..dce11f3 100644
--- a/iclean.icl
+++ b/iclean.icl
@@ -35,16 +35,20 @@ import ExtraString
 temp_path :== "/tmp/"
 temp_module :== "iclean"
 readline_history :== "/home/.iclean_history"
-template :== map ((+++) "import ")
-	[ "StdEnv"
-	, "StdMaybe"
-	, "StdDynamic"
-	, "genLibTest"
-	]
+template :== map ((+++) "import ") ["StdEnv", "StdDynamic", "genLibTest"]
 // END SETTINGS
 
 temp_file :== temp_path +++ temp_module +++ ".icl"
 
+help :==
+	"\tInteractive Clean - known commands:\n\n" +++
+	"\t:quit\t\t\tExit iClean\n" +++
+	"\t:mem\t\t\tDisplay current memory\n" +++
+	"\t:help\t\t\tDisplay this message\n\n" +++
+	"\t:import MODULE\t\tAdd an import to the memory\n" +++
+	"\t:def F X1 .. X2 = RHS\tAdd a rewrite rule to the memory\n" +++
+	"\t:undef F\t\tRemove all rewrite rules starting with 'F ' from the memory\n"
+
 Start :: *World -> *World
 Start w
 # w = setReadLineName "iClean" w
@@ -66,6 +70,8 @@ where
     | s == ":mem"           = loop mem True (print (join "\n" mem) w)
     | matches ":import " s  = loop (mem ++ [skip 1 s]) True w
     | matches ":def " s     = loop (mem ++ [skip 5 s]) True w
+	| matches ":undef " s   = loop (filter (undef (skip 7 s)) mem) True w
+	| s == ":help"          = loop mem True (print help w)
     | matches ":" s         = loop mem False (print ("Unknown command\n") w)
     # w                     = writemodule mem s w
     # (r,w)                 = compile temp_path temp_module w
@@ -74,6 +80,9 @@ where
     | r <> 0                = loop mem False w
     = loop mem True w
 
+	undef :: !String !String -> Bool
+	undef n h = not (matches (n +++ " ") h)
+
 // iClean functions
 checkedWorldFunc :: (a *World -> (Bool, *World)) !String !a !*World -> *World
 checkedWorldFunc f err s w