Basic Expression Workflow

gistfile1.txt

// Get the value before the operator
if((i - 1) < 0){
    throw new SyntaxException ("Badly Formed Expression.", tokens);
}
Value numerator = this.engine.evaluate(tokens.get(i - 1), scope);

// Get the value after the operator
if((i + 1) >= tokens.size()){
    throw new SyntaxException ("Badly Formed Expression.", tokens);
}
Value divisor = this.engine.evaluate(tokens.get(i + 1), scope);

Expression expression = new Expression(numerator, divisor);

// Preform the operation
Token newToken = evaluateExpression(expression, scope);

// Replace Left Value, Operator, and Right Value with the new Value
slice(tokens, i-1, i+1);
tokens.add(i - 1, newToken);