Exists for lists and lines

docs/syntax.md

@@ -122,6 +122,8 @@ Checks if a variable exists with a direct reference. If the variable exists, out
 
 Usage `exists &var1 &var2`
 
+Note: You can also replace &var1 with a list or line reference to check if it also exists
+
 #### setlist
 
 Allows you to initialize a list.

src/main.cpp

@@ -542,7 +542,7 @@ Literal exec(vector<Instruction> in, bool executingFunction) {
                         newLine.lineNum = (*currentLabels)[ln.label];
                         l.args[j] = newLine;
                     } else {
-                        error("Could not find label " + ln.label);
+                        if (l.inst != Instructions::Exists) error("Could not find label " + ln.label);
                     }
                 }
             }
@@ -1661,23 +1661,37 @@ Literal exec(vector<Instruction> in, bool executingFunction) {
                     error("Could not find all arguments required for Exists inbuilt");
                 }
                 {
-                    Direct ref1;
-                    if (holds_alternative<Direct>(l.args[0])) {
-                        ref1 = get<Direct>(l.args[0]);
-                    } else {
-                        error("First argument of exists must be a direct reference");
-                    }
-
                     Direct ref2;
                     if (holds_alternative<Direct>(l.args[1])) {
                         ref2 = get<Direct>(l.args[1]);
+                    } else {
+                        error("Second argument of exists must be a direct reference");
                     }
 
-                    if (variables.find(ref1.varName) != variables.end()) {
-                        variables[ref2.varName].val = true; 
-                    } else {
-                        variables[ref2.varName].val = false;
+                    bool exists = false;
+                    if (holds_alternative<Direct>(l.args[0])) {
+                        if (variables.find(get<Direct>(l.args[0]).varName) != variables.end()) {
+                            exists = true;
                         }
+                    } else if (holds_alternative<ListRef>(l.args[0])) {
+                        if (lists.find(get<ListRef>(l.args[0]).listName) != lists.end()) {
+                            exists = true;
+                        }
+                    } else if (holds_alternative<Line>(l.args[0])) {
+                        Line line = get<Line>(l.args[0]);
+                        if (line.isLabel) {
+                            if (labels.find(line.label) != labels.end()) {
+                                exists = true;
+                            }
+                        } else {
+                            if (line.lineNum > 0 && line.lineNum <= in.size()) {
+                                exists = true;
+                            }
+                        }
+                    } else {
+                        error("First argument of exists must be a direct, list, or line reference");
+                    }
+                    variables[ref2.varName].val = exists;
                 }
                 break;
             /*

tests/exists.grnd

@@ -0,0 +1,20 @@
+set &testVar "dingus"
+exists &testVar &exist
+stdlnout $exist
+
+setlist *myList "item"
+exists *myList &exist
+stdlnout $exist
+
+@dingus
+exists %dingus &exist
+stdlnout $exist
+
+exists &doesNotExist &exist
+stdlnout $exist
+
+exists *doesNotExist &exist
+stdlnout $exist
+
+exists %doesNotExist &exist
+stdlnout $exist