Prepare for error guards

1 files changed, 20 insertions, 8 deletions

diff --git a/eval.c b/eval.c
index 58a745b..4131871 100644
--- a/eval.c
+++ b/eval.c
@@ -113,24 +113,36 @@ retry:
 			int guardOK = 1;
 			if(stmt->toks[0]->tag != ArrayTag)
 				guardOK = 0;
-			else if(GetSize(stmt->toks[0]->array) != 1)
+			else if(!stmt->errorguard && GetSize(stmt->toks[0]->array) != 1)
+				guardOK = 0;
+			else if(stmt->errorguard && GetSize(stmt->toks[0]->array) < 1)
 				guardOK = 0;
 			else if(GetType(stmt->toks[0]->array) != AtypeInt)
 				guardOK = 0;
-			else if(stmt->toks[0]->array->intdata[0] != 0 && stmt->toks[0]->array->intdata[0] != 1)
+			else if(!stmt->errorguard && stmt->toks[0]->array->intdata[0] != 0 && stmt->toks[0]->array->intdata[0] != 1)
 				guardOK = 0;
-			if(!guardOK)
-				throwerror(L"Guard expected single valued boolean", EDomain);
-			else{
+			if(!guardOK){
+				if(!stmt->errorguard)
+					throwerror(L"Guard expected single valued boolean", EDomain);
+				else
+					throwerror(L"Error guard expected an array of error numbers", EDomain);
+			}else{
 				stop = 0;
-				if(stmt->toks[0]->array->intdata[0] == 1)
-					return eval(stmt->guard, toplevel);
+				if(!stmt->errorguard){
+					if(stmt->toks[0]->array->intdata[0] == 1)
+						return eval(stmt->guard, toplevel);
+				}else
+					print("Not registering error guard for error codes: %S\n", ppdatum(stmt->toks[0]));
 			}
 		}
 		if(stmt->next && !stop)
 			return eval(stmt->next, toplevel);
-		else
+		else if(!stmt->guard)
 			return stmt->toks[0];
+		else{
+			throwerror(L"No value produced", EValue);
+			return nil;
+		}
 	}else
 		return nil;
 }