diff --git a/moo/kernel/Apex.moo b/moo/kernel/Apex.moo
index 07fe91e..b6de516 100644
--- a/moo/kernel/Apex.moo
+++ b/moo/kernel/Apex.moo
@@ -408,30 +408,33 @@ class UndefinedObject(Apex)
 }
 
 
-pooldic ErrorCode
+
+class Error(Apex)
 {
-(* migrate it into Error class *)
-	#NONE      := error(0).
-	#GENERIC   := error(1).
-	#NOIMPL    := error(2).
-	#SYSERR    := error(3).
-	#INTERN    := error(4).
-	#SYSMEM    := error(5).
-	#OOMEM     := error(6).
-	#INVAL     := error(7).
-	#NOENT     := error(8).
+}
+
+pooldic Error.Code
+{
+	GENERIC   := error(0).
+	NOIMPL    := error(1).
+	SYSERR    := error(2).
+	INTERN    := error(3).
+	SYSMEM    := error(4).
+	OOMEM     := error(5).
+	INVAL     := error(6).
+	NOENT     := error(7).
 (* add more items... *)
 }
 
-class Error(Apex)
+extend Error
 {
 	(* ----------------------------
 	TODO: support constant declaration...
 
 	#const
 	{
-		#NONE := error(0).
-		#GENERIC := error(1).
+		NONE := error(0).
+		GENERIC := error(1).
 	}
 	-------------------------------- *)
 
diff --git a/moo/kernel/Collect.moo b/moo/kernel/Collect.moo
index ddfd9a9..15090a1 100644
--- a/moo/kernel/Collect.moo
+++ b/moo/kernel/Collect.moo
@@ -1,6 +1,42 @@
 
 class Collection(Object)
 {
+	method isEmpty
+	{
+		^self size <= 0
+	}
+
+	method notEmpty
+	{
+		^self size > 0
+	}
+	
+	method size
+	{
+		(* Each subclass must override this method because
+		 * it interates over the all elements for counting *)
+		| count |
+		count := 0.
+		self do: [ :el | count := count + 1 ].
+		^count
+	}
+	
+	method do: block
+	{
+		^self subclassResponsibility: #do
+	}
+	
+	method detect: block
+	{
+		self do: [ :el | if (block value: el) { ^el } ].
+		^Error.Code.NOENT
+	}
+	
+	method detect: block ifNone: exception_block
+	{
+		self do: [ :el | if (block value: el) { ^el } ].
+		^exception_block value.
+	}
 }
 
 ## -------------------------------------------------------------------------------
@@ -193,7 +229,7 @@ class Set(Collection)
 		}.
 
 		##upsert ifFalse: [^ErrorCode.NOENT].
-		if (upsert) {} else { ^ErrorCode.NOENT }.
+		if (upsert) {} else { ^Error.Code.NOENT }.
 
 		ntally := self.tally + 1.
 		if (ntally >= bs)
@@ -280,7 +316,7 @@ class Set(Collection)
 			index := (index + 1) rem: bs.
 		}.
 
-		^ErrorCode.NOENT.
+		^Error.Code.NOENT.
 	}
 
 	method __remove_at: index
@@ -472,11 +508,11 @@ pooldic Log
 	## these items must follow defintions in moo.h
 	## -----------------------------------------------------------
 
-	#DEBUG := 1.
-	#INFO  := 2.
-	#WARN  := 4.
-	#ERROR := 8.
-	#FATAL := 16.
+	DEBUG := 1.
+	INFO  := 2.
+	WARN  := 4.
+	ERROR := 8.
+	FATAL := 16.
 }
 
 class SystemDictionary(Set)
diff --git a/moo/lib/comp.c b/moo/lib/comp.c
index d83417d..eea8bc8 100644
--- a/moo/lib/comp.c
+++ b/moo/lib/comp.c
@@ -6630,9 +6630,9 @@ static int __compile_pooldic_definition (moo_t* moo)
 
 	GET_TOKEN (moo);
 
-	while (TOKEN_TYPE(moo) == MOO_IOTOK_SYMLIT)
+	while (TOKEN_TYPE(moo) == MOO_IOTOK_IDENT)
 	{
-		lit = moo_makesymbol (moo, TOKEN_NAME_PTR(moo) + 1, TOKEN_NAME_LEN(moo) - 1);
+		lit = moo_makesymbol (moo, TOKEN_NAME_PTR(moo), TOKEN_NAME_LEN(moo));
 		if (!lit || add_to_array_literal_buffer (moo, lit) <= -1) return -1;
 
 		GET_TOKEN (moo);