PLC Laboratory 7
Contents
Interpreter of Arithmetic Expressions Using ANTLR
Using ANTLR, implement an interpreter of arithmetic expressions. These expressions contain +, -, *, / operators (with common priorities and left associativity) and parentheses. To simplify the task, consider we have only binary operators. There are no unary operators in our language.
As a starting point, you can use following ANTLR grammar (it describes different kind of expressions): ANTLR input file
Input specification
In the input, there are expressions, they are written in formatting. Each expression ends with semicolon. Numbers can be written similarly to C language constants. it can be either: decimal , octal (starting with zero) or hexadecimal (starting with characters 0x) number.
Output specification
For each expression write one line containing the result – the computed value of the expression. If there is any error in the input, you can stop the computation.
Example
- Input
012-10; 2 * (0xff+5);
0x23e5-0x201;
- Output
0
520
8676
