SDRL

Started January 23, 2004

SDRL is a very strange language I made near the end of university. It was the evolution of efforts to make a language with an overly simplified syntax. The previous languages were purposefuly obtuse and all language constructs were a single character. With SDRL, the actual parser was selectable, with the default eventually being a scheme/lisp-like syntax, but it was designed such that almost everything was a function. The only 'form' (in the scheme sense) is the (code ...) expression, which returns an expression-type object (the parsed AST) for the code that appears within the brackets. Everything else is a function, including the (if ...) statements, which are passed the conditional blocks as expression-type values. It then evaluates the appropriate expression based on the result of the conditional expression.

Running

There shouldn't be a need to run ./configure before compiling. After compiling, a single binary named 'sdrl' will be created in bin/, as well as some static libraries lib/. There is no install option.

tar -xvzf sdrl.tar.gz
cd sdrl
make
bin/sdrl test.sdrl

Towers of Hanoi Example in SDRL

(set move-tower (lexblock
    (setlist (@ func from to discs) ($ _))
    (if (= ($ discs) 1)
        (code
            (move-disc ($ from) ($ to)))
        (code
            (move-tower ($ from)
                        (- 6 ($ from) ($ to))
                        (- ($ discs) 1))
            (move-disc ($ from) ($ to))
            (move-tower (- 6 ($ from) ($ to))
                        ($ to)
                        (- ($ discs) 1))))))

(set move-disc (lexblock
    (setlist (@ func from to) ($ _))
    (print "Moved disc from " ($ from) " to " ($ to) "\n")))

(move-tower 1 3 3)

News

Version 0.3 Released!

December 23, 2007 It's been a long long time since the last release and most of the changes in this release were implemented shortly after that last release but as things go, I drifted into other projects and never got around to releasing those changes. I picked up the project again this fall and mostly reorganized and tidied up the code a bit but again drifted into other things. This release is somewhat hasty since I know full well that the planned changes will not be implemented within a reasonable time-frame and the changes from version 0.2 are actually quite extensive. I plan on moving to git (hopefully tomorrow) before I take up coding again. Major features in this release include an events/continuation stack which allows for tail recursion, slightly improved error handling, and properly organized libraries. The parser has been completely removed from the core and put into the base library instead, allowing for easy selection of the parser. The primary parser has been changed to the "lispy" parser. I also added the beginnings of a proper automated test suite. Plans for the next release are primarily to polish and optimize the code where possible.

Version 0.2 Released!

March 30, 2005 Version 0.2 has been released. Its been over a year and after some time away I have completely re-written the interpreter. It is completely incompatible with version 0.1 (but I assure you, much better). I already have plans for a next release but I am not sure how much I will implement by then. Possible features include a dynamic parser, full garbage collection (and therefore references), and better error handling/reporting mechanisms.

Version 0.1 Released!

February 09, 2004 Version 0.1 has been released. It is very primative but it works. I already have some ideas for major improvements but I am unsure when I will get around to implementing them.

Get the Source

git clone git@github.com:transistorfet/sdrl