Valid operators are
+ - * / ^
= += -= *= /= ^=
Valid tokens are
"5" (String)
"variable-name" (Variable name stored in 'variables' HashMap)
"5.0" (String)
5 (Integer)
5.0 (Double)
otherwise -> Exception
Example Usage
HashMap<String, Double> variables = new HashMap<>();
variables.put("PI", Math.PI);
variables.put("E", Math.E);
variables.put("abc", 5.0);
TokenList threePlusPI = new TokenList("+", 3, "PI");
TokenList fiveMinusE = new TokenList("-", 5.0, "E");
TokenList multiplyFMTAndTPF = new TokenList("*", fiveMinusE, threePlusPI);
TokenList variableXYZ = new TokenList("=", "xyz", multiplyFMTAndTPF);
TokenList variableAdd = new TokenList("*=", "abc", variableXYZ);
System.out.println(parse(variableAdd, variables) + "\n" + variables);Evaluates
PI = 3.1415...
E = 2.71...
abc = 5.0...
abc *= xyz = (5.0 - E) * (3 + PI)
Evaluation order
(5.0 - E) * (3 + PI) -> xyz -> abc