HaskellTreeDSL

A minimal BASIC-like Domain Specific Language (DSL), implemented in Haskell 🧐.

This project is a demo, with 'minimum viable' BASIC language features largely implemented through AI code generation.

The BASIC code, for the tree outline (without decorations), looks like this:

10 FOR i = 1 TO 12
20 LET spaces = 12 - i
30 LET tree = i * 2 - 1
40 FOR j = 1 TO spaces
45 COLOR "Green"
50 PRINT " ";
60 NEXT j
70 FOR k = 1 TO tree
80 PRINT "/";
90 NEXT k
100 PRINT
110 NEXT i
125 COLOR "Brown"
120 PRINT "         ||||"
125 COLOR "Red"
130 PRINT "       ________"

Background

ChatGPT generated the BASIC outline for the tree, without decorations, and the fundamentals of the Haskell parser.

To improve the accuracy of the generated code, a custom GPT was used, Haskell Parser Helper GPT, with key help files from Megaparsec loaded as knowledge. This did seem to improve the generated code accuracy to a degree, but further refinement is needed. The parser is not entirely AI generated, it needed a little tweaking to fix a couple of end of line / keyword handling issues that crept in.

devcontainer

This project 'should' launch in a devcontainer: https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers

run

build and run as a binary:

stack run

to debug / develop

run in ghci:

stack ghci

ghci> SamplePrograms.main

SamplePrograms.hs contains other programs to run, with a little tweaking.

test cases

run the test cases:

stack ghci --test

(option 2)

ghci> Main.main

---

Additional notes:

Testing

List the tests:

stack test --test-arguments "--dry-run"

Run a specific test:

stack test --test-arguments "-m \"parses valid LET statement"\"

stack test --test-arguments "-m \"parses valid LET statement with arithmetic"\"

stack test --test-arguments "-m \"FOR NEXT program tests/parses valid FOR statement in program, with PRINT"\"

stack test --test-arguments "-m \"FOR NEXT tests"\"

traceShow

Add traceShow within parsers to log the parser state:

  -- Debugging prints
  let debugInfo = (ln, varName, startExpr, endExpr)
  traceShow debugInfo $ return ()