haskell-tree-sitter

Alternative Haskell bindings to the Tree-sitter parsing library.

These bindings do not strive to provide a native Haskell experience, and instead focus on making the full C API of Tree- sitter accessible. Most of the heavy lifting is done by bindings-DSL directly. The only exception is that for each ts_<>() function that wants struct as value, a hs_<>() function has been created that takes the same struct as pointer, since GHC does not support passing structures as values.

Setup

You probably want to add it as a submodule in your repo and as a package in your stack config file.

You'll also need to obtain the Tree-sitter compatible grammar for your language.

Basic usage

import TreeSitter.Api
...

foreign import ccall unsafe "vendor/tree-sitter-<yourlanguage>/src/parser.c tree_sitter_<yourlanguage>" c'tree_sitter_<yourlanguage> :: Ptr C'TSLanguage

parse :: String -> ...
parse s =  alloca $ \root_node -> do
    parser <- c'ts_parser_new
    c'ts_parser_set_language parser c'tree_sitter_<yourlanguage>

    (str, len) <- newCStringLen s
    tree <- c'ts_parser_parse_string parser nullPtr str (fromIntegral len)
    c'hs_tree_root_node tree root_node

    ...