Parsing error with field having hyphen sign.

[nrmohta]

Hi,
I am facing parsing error when field name in expression is having hyphen sign.
Example expression - field-plus+field-minus
variables - field-plus and field-minus
Objective - I want to perform addition of these 2 variables.

My code

Map<String, Double> map = new HashMap<>();
map.put("field-plus", 5d);
map.put("field-minus", 10d);
Expression e = new ExpressionBuilder("field-plus+field-minus" )
.variables("field-plus","field-minus")
.build()
.setVariables(map);
double result = e.evaluate();

Its throwing - Unknown function or variable 'field' at pos 0 in expression 'field-plus+field-minus'
I have also tried option to use single quote character in expression like "'field-plus'+'field-minus'" and setting variable with single quote but still it gives error to parse single quote character.

Is there any other way to achieve my goal ? If its a defect , is there any plan to fix it ?
Please suggest.

Thanks,
Neeraj.