added moo_process_t.perr and Processor>>primError to capture the last error set by a primitive function

moo/kernel/Apex.moo

@@ -1,4 +1,38 @@
 class Apex(nil)
+{
+}
+
+class Error(Apex)
+{
+}
+
+pooldic Error.Code
+{
+	ENOERR     := error(0).
+	EGENERIC   := error(1).
+	ENOIMPL    := error(2).
+	ESYSERR    := error(3).
+	EINTERN    := error(4).
+	ESYSMEM    := error(5).
+	EOOMEM     := error(6).
+	EINVAL     := error(7).
+	ENOENT     := error(8).
+	EPERM      := error(12).
+	ERANGE     := error(20).
+(* add more items... *)
+}
+
+(*pooldic Error.Code2 
+{
+	>> CAN I SUPPORT this kind of redefnition? as of now, it's not accepted because 
+	>> Error.Code2.EGENERIC is not a literal. Should i treate pooldic members as a constant
+	>> and treat it as if it's a literal like? then even if the defined value changes,
+	>> the definition here won't see the change... what is the best way to tackle this issue?
+
+	EGENERIC := Error.Code2.EGENERIC.
+}*)
+
+extend Apex
 {
 	## -------------------------------------------------------
 	## -------------------------------------------------------
@@ -126,35 +160,49 @@ class Apex(nil)
 
 	method basicAt: index
 	{
+		| perr |
+		
 		<primitive: #_basic_at>
-		self index: index outOfRange: (self basicSize).
+
+## TODO: create a common method that translate a primitive error to some standard exceptions of primitive failure.
+		perr := thisProcess primError.
+		if (perr == Error.Code.ERANGE) { self index: index outOfRange: (self basicSize) }
+		elsif (perr == Error.Code.EPERM) { self messageProhibited: #basicAt }
+		else { self primitiveFailed }
 	}
 
 	method basicAt: index put: anObject
 	{
+		| perr |
+		
 		<primitive: #_basic_at_put>
-## TODO: proper error handling
+
-(*
+		perr := thisProcess primError.
-		if (primitiveError == error(generic))
+		if (perr == Error.Code.ERANGE) { self index: index outOfRange: (self basicSize) }
-		{
+		elsif (perr == Error.Code.EPERM) { self messageProhibited: #basicAt:put: }
-		}
+		else { self primitiveFailed }
-		else
-		{
-			self index: index outOfRange: (self basicSize).
-		}*)
-		self index: index outOfRange: (self basicSize).
 	}
 
 	method(#class) basicAt: index
 	{
+		| perr |
 		<primitive: #_basic_at>
-		self index: index outOfRange: (self basicSize).
+
+		perr := thisProcess primError.
+		if (perr == Error.Code.ERANGE) { self index: index outOfRange: (self basicSize) }
+		elsif (perr == Error.Code.EPERM) { self messageProhibited: #basicAt:put: }
+		else { self primitiveFailed }
 	}
 
 	method(#class) basicAt: index put: anObject
 	{
+		| perr |
 		<primitive: #_basic_at_put>
-		self index: index outOfRange: (self basicSize).
+
+		perr := thisProcess primError.
+		if (perr == Error.Code.ERANGE) { self index: index outOfRange: (self basicSize) }
+		elsif (perr == Error.Code.EPERM) { self messageProhibited: #basicAt:put: }
+		else { self primitiveFailed }
 	}
 
 	(* ------------------------------------------------------------------
@@ -489,32 +537,6 @@ class UndefinedObject(Apex)
 }
 
 
-class Error(Apex)
-{
-}
-
-pooldic Error.Code
-{
-	EGENERIC   := error(1).
-	ENOIMPL    := error(2).
-	ESYSERR    := error(3).
-	EINTERN    := error(4).
-	ESYSMEM    := error(5).
-	EOOMEM     := error(6).
-	EINVAL     := error(7).
-	ENOENT     := error(8).
-(* add more items... *)
-}
-
-(*pooldic Error.Code2 
-{
-	>> CAN I SUPPORT this kind of redefnition? as of now, it's not accepted because 
-	>> Error.Code2.EGENERIC is not a literal. Should i treate pooldic members as a constant
-	>> and treat it as if it's a literal like? then even if the defined value changes,
-	>> the definition here won't see the change... what is the best way to tackle this issue?
-
-	EGENERIC := Error.Code2.EGENERIC.
-}*)
 
 extend Error
 {

moo/kernel/Process.moo

@@ -1,33 +1,21 @@
 
 class(#pointer) Process(Object)
 {
-	var initial_context, current_context, state, sp, prev, next, sem.
+	var initial_context, current_context, state, sp, prev, next, sem, perr.
 
 	method new
 	{
 		"instantiation is not allowed"
-		^nil. "TODO: raise an exception"
+		^nil. "TODO: raise an exception or return an error"
 	}
 
-	method prev
+	method prev { ^self.prev }
-	{
+	method next { ^self.next }
-		^self.prev.
-	}
 
-	method next
+	method next: process { self.next := process }
-	{
+	method prev: process { self.prev := process }
-		^self.next.
-	}
 
-	method next: process
+	method primError { ^self.perr }
-	{
-		self.next := process.
-	}
-
-	method prev: process
-	{
-		self.prev := process.
-	}
 
 	method resume
 	{

moo/lib/comp.c

@@ -3214,8 +3214,13 @@ if super is variable-nonpointer, no instance variable is allowed.
 
 				GET_TOKEN (moo);
 
-				/* [NOTE] default value assignment. only a literal is allowed */
+				/* [NOTE] default value assignment. only a literal is allowed 
-				lit = token_to_literal (moo, 1);
+				 *    the initial values for instance variables and 
+				 *    class instance variables are set to read-only.
+				 *    this is likely to change if the actual initial
+				 *    value assignment upon instantiation employes
+				 *    deep-copying in moo_instantiate() and in the compiler. */
+				lit = token_to_literal (moo, dcl_type != VAR_CLASS);
 				if (!lit) return -1;
 
 				/* set the initial value for the variable added above */
@@ -4310,7 +4315,7 @@ static int __read_array_literal (moo_t* moo, int rdonly, moo_oop_t* xlit)
 				if (__read_byte_array_literal (moo, &lit) <= -1) return -1;
 				if (rdonly)
 				{
-					MOO_ASSERT (moo, MOO_OOP_IS_POINTER(lit));
+					MOO_ASSERT (moo, lit && MOO_OOP_IS_POINTER(lit));
 					MOO_OBJ_SET_FLAGS_RDONLY (lit, 1);
 				}
 				break;
@@ -7071,7 +7076,9 @@ static MOO_INLINE moo_oop_t token_to_literal (moo_t* moo, int rdonly)
 		}
 
 #if 0
-/* TODO: if a constant name is specified (constant defined in a class)  */
+/* TODO: if a constant name is specified (constant defined in a class) or
+ *       another variable with the default initialization value
+ *    class { var x := 20, y := x. } */
 		case MOO_IOTOK_IDENT:
 		case MOO_IOTOK_IDENT_DOTTED:
 #endif

moo/lib/exec.c

@@ -160,6 +160,7 @@ static moo_oop_process_t make_process (moo_t* moo, moo_oop_context_t c)
 	proc->initial_context = c;
 	proc->current_context = c;
 	proc->sp = MOO_SMOOI_TO_OOP(-1);
+	proc->perr = MOO_ERROR_TO_OOP(MOO_ENOERR);
 
 	MOO_ASSERT (moo, (moo_oop_t)c->sender == moo->_nil);
 
@@ -3821,9 +3822,11 @@ static int start_method (moo_t* moo, moo_oop_method_t method, moo_oow_t nargs)
 			}
 			else
 			{
+				moo->errnum = MOO_EINVAL;
 				MOO_DEBUG1 (moo, "Cannot call primitive numbered %zd - invalid number\n", pfnum);
 			}
 
+			moo->processor->active->perr = MOO_ERROR_TO_OOP(moo->errnum);
 			goto activate_primitive_method_body;
 		}
 

moo/lib/moo.h

@@ -704,7 +704,7 @@ struct moo_context_t
 };
 
 
-#define MOO_PROCESS_NAMED_INSTVARS 7
+#define MOO_PROCESS_NAMED_INSTVARS 8
 typedef struct moo_process_t moo_process_t;
 typedef struct moo_process_t* moo_oop_process_t;
 
@@ -725,6 +725,7 @@ struct moo_process_t
 	moo_oop_process_t   next;
 
 	moo_oop_semaphore_t sem;
+	moo_oop_t           perr; /* last error set by a primitive function */
 
 	/* == variable indexed part == */
 	moo_oop_t slot[1]; /* process stack */