I'm trying to use geiser-mode in emacs to run racket code. I've been able to install geiser-mode and launched racket.
Yet when I run a definition twice I got the following error. this name was defined previously and cannot be re-defined
here is simple example
(define a (* 1 4))
a
run twice
In the debugger
#a: this name was defined previously and cannot be re-defined
#in: a
racket appears to behave differently in a file and the REPL. This file will throw an error:
#lang racket
(define a 5)
(define a 6)
And this REPL session will not:
> (define a 5)
> a
5
> (define a 6)
> a
6
The behavior is because of the way modules work. When working in a file, there is an implicit module. Once the symbol a has been defined in that module another symbol with the same name cannot be defined within that module. The REPL simply expands forms without all the ceremony of modules.
