REPL support

Before when I forgot the signature of procedures, I always search the internet (usually these procedures were defined in R6RS). However Sagittarius has a document which contains R6RS procedures as well. Why didn't I use it? It's because searching the internet was usually faster than open the document HTML and look it up.

And now, I thought this is inconvenient. (It was!). So I made a library called (sagittarius interactive support) which provides a macro 'document'. This macro look up given name from the document. For this purpose, from 0.3.4 document will be located in the install path.

Then I have also noticed, it was really pain in the ass to type '(import (sagittarius interactive support)' each time when I run the REPL. So I added initialisation file '.sashrc' loading to REPL. REPL will search the file from either $HOME or $USERPROFILE and if it found, then load the contents to the REPL environment.

Now it's a bit more convenient.