How to set a String into newly created Context's children - string

Question

I have a parser that calls a visitX method with an XContext that contains an expression that resolves to an ArrayNode and a FunctionName. I can retrieve the function's object and want to call invoke on it for each element in this array but the function takes an ExpressionVisitor and a YContext. I can create a new YContext(XContext) and the children are empty as expected. I need to add my array.get(i) as a TerminalNode into the children array so the function receiving the YContext can check the number of children (1) and then get the value (e.g., ctx.exprValues().exprList().expr(0)) from the YContext.
TerminalNodeImpl can take a Token (which is an interface) and I haven't found a way to create a Token using the implementing classes that can take an JsonNode value (e.g., String, int, Object).
The YContext children is a List but I am not sure what implements ParseTree that I could construct using the JsonNode value.
I tried parsing the JsonNode value using code like this but I can't get anything in tokens that I could use addAnyChild to my new context...
for (int i=0;i<mapArray.size();i++) {
ANTLRInputStream input = new ANTLRInputStream(mapArray.get(i).asText());
MappingExpressionLexer lexer = new MappingExpressionLexer(input);
CommonTokenStream tokens = new CommonTokenStream(lexer);
I am sure I'm overlooking something simple. In other situations I've been able to push the value onto the stack but in this case the functions I can call all take the YContext so I need to put the value into the YContext.children somehow.

Answer 1

The solution is convoluted but necessary based on how the expression is defined. I traced the ctx being passed to the function so I could get its structure:
Function_callContext:
---------------------
TerminalNodeImpl $string 44 '$string'
ExprValuesContext
TerminalNodeImpl ( 2 '('
ExpressionListContext
NumberContext
TerminalNodeImpl 1 22 '1'
TerminalNodeImpl ) 3 ')'
TerminalNodeImpl $string 44 '$string'
Because the parser is looking for:
expr :
...
| VAR_ID exprValues # function_call
...
;
...
exprList : expr (',' expr)* ;
exprValues : '(' exprList ')' ;
VAR_ID : '$' ID ;
ID : [a-zA-Z] [a-zA-Z0-9_]*;
and I found the CommonTokenFactory to let me create the Token I could put in the TerminalNodeImpl so I could build up the correct context.
Here is the code (I only implemented the NUMBER at this point but will add exceptions and other types later... My test was to transform an array of numbers to an array of strings using the $map([1..5],$string) example (where [1..5] is a sequence that becomes the array.
for (int i = 0; i < mapArray.size(); i++) {
Function_callContext callCtx = new Function_callContext(ctx);
// note: callCtx.children should be empty unless carrying an
// exception
ExprListContext elc = new ExprListContext(callCtx.getParent(),callCtx.invokingState);
ExprValuesContext evc = new ExprValuesContext(callCtx.getParent(),callCtx.invokingState);
evc.addAnyChild(new TerminalNodeImpl(CommonTokenFactory.DEFAULT.create(MappingExpressionParser.T__1,"(")));
CommonToken token = null;
JsonNode element = mapArray.get(i);
switch (element.getNodeType()) {
case ARRAY: {
break;
}
case BINARY:
break;
case BOOLEAN:
break;
case MISSING:
break;
case NULL:
break;
case NUMBER:
token = CommonTokenFactory.DEFAULT.create(MappingExpressionParser.NUMBER,element.asText());
TerminalNodeImpl tn = new TerminalNodeImpl(token);
NumberContext nc = new NumberContext(callCtx);
nc.addAnyChild(tn);
elc.addAnyChild(nc);
evc.addAnyChild(elc);
break;
case OBJECT:
break;
case POJO:
break;
case STRING:
break;
default:
break;
}
evc.addAnyChild(new TerminalNodeImpl(CommonTokenFactory.DEFAULT.create(MappingExpressionParser.T__1,")")));
callCtx.addAnyChild(var);
callCtx.addAnyChild(evc);
result = function.invoke(this, callCtx);
resultArray.add(result);
}