1 # evpf - postfix evaluator

3 evpf (**ev**aluate **p**ost**f**ix is a simple postfix expression evaluator

4 written as a learning project in rust. It supports both command line and

5 interactive mode.

7 ## Command line mode

9 evpf <expression>

11 where `<expression>` is a postfix expression like `20 30 + 11 -` etc.

12 Currently only 4 operators are supported: `+`, `-`, `*` and `/`. (In command

13 line mode, `*` has to be escaped using `\*` to work properly.)

15 ## Interactive mode

17 Interactive mode displays a prompt where expressions can be evaluated by

18 typing into the prompt (line editing and session-history supported by

19 `rustyline`.

21 evpf>

23 In interactive mode, apart from entering expressions, the following commands

24 are supported

26 * `q` or `Q` - quit

27 * `?` or `h` or `H` - help