Translator – Unary Operators

Up to now, the subject of operators have referred to binary operators or operators with two operands. Unary operators only have only one operand. Only two unary operators are currently planned, - (negate) and NOT. Unary operators are found in expressions preceding an operand. Examples are -A + B, A + -B, and -(A+B). Two unary operators appearing together will be allowed, for example A + --B, but the translator will make no effort to try and optimize this (it's up to the programmer to make an effort to not do stuff like this).

When the current token contains a unary operator, it will be pushed directly onto the operator stack, since there are no operators currently planned that have the highest precedence. With the highest precedence, they will come off the stack whenever a binary operator is processed.

There will be two negate operators, one for integers (NegInt) and one for doubles (NegDbl), so the unary – operator will not need to insert any conversion operator. However, the NOT operator will only work with integers, so if the operand is a double, a hidden double to integer conversion operator (CvtInt) needs to be added to the RPN list before adding the NOT operator.