The expression evaluator is due to Mark Morley. Some modifications have been made, to add the possibility to evaluate objects. It is possible to use the 4 operators +,-, *, / and parentheses. One can also define and use variables, and use the usual mathematical functions.
Everything that is not recognized by the interpreter as a command or a program is supposed to be a numerical expression. It is computed and the result is printed on screen. For instance
- interpcom -> a=2
2.000000
- interpcom -> b=3
3.000000
- interpcom -> a+b
5.000000
- interpcom -> cos(a)
-0.416147
It is possible to use numerical expressions as arguments of commands (or command files and programs) (cf. 7.6 and 6).