echo expression values, treat more things as expressions

[lukeasrodgers]

It would be really nice to just type an identifer, and have its value (or some representation of it, for functions/subroutines) echoed, e.g.:

> integer :: a = 1
1
> a
1

Also to treat more things as expressions, and echo their value, e.g.:

> integer :: a = 1
1
> a + 1
2 
> integer :: b, c
> b = 3
3
> c = a + b
4

Could probably get 60% of the way there by: if last statement was an assignment, run the program, write(,) the value of the last assignment; if a statement cannot be classified but we can treat it as an expression, store it in some temp variable, run program, write(,) the value of that temp variable.

• treat assignments like expressions
• treat lone variable names as expressions
• treat declarations/multi-declarations as expressions
• echo symbol or something for functions, subroutines