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read-eval-print-loopmit-scheme

mit-scheme REPL with command line history and tab completion


I'm reading SICP and I'm using mit-scheme installed on my os x 10.8 laptop via homebrew.

Everything works as advertised, however I'm spoiled by the ease with which I get tab completion and command line history in REPL's for runtimes like Python and Node.js.

I'm not looking for anything heavy duty, but these features are pretty easy to come by in modern REPL's (it's just a simple startup file in Python and can be implemented in a few lines in Node.js).

Is there an easy way to get tab completion and command history in the mit-scheme REPL without a heavy-duty application or having to switch to emacs (i.e. in an xterm terminal)?


Solution

  • Install the readline wrapper:

    brew install rlwrap

    Once installed, rlwrap scheme will give you persistent history, paren matching, and tab completion. I typically use rlwrap with the following arguments:

    -r Put all words seen on in- and output on the completion list.

    -c Complete filenames

    -f Specify a list of words to use for tab completion. I'm using an abridged list of bindings from the MIT Scheme Reference Manual. Rather than republish the list here, you can find it in this gist. I have this file stored in "$HOME"/scheme_completion.txt

    rlwrap -r -c -f "$HOME"/scheme_completion.txt scheme

    1 ]=> (flo:a <tab tab>
    flo:abs    flo:acos   flo:asin   flo:atan   flo:atan2  
    1 ]=> (flo:abs -42.0)
    
    ;Value: 42.