strongly typed C++ adaptors for parser grammars

[ikrima]

TLDR

• Dev quality of life C++ bindings out of a custom grammar for walking/traversing nodes
• Don't think this really belongs in tree-sitter main but sharing for fun/maybe others have similar uses

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I love the bare C, dependency free nature of tree-sitter. But overtime, found traversing the parse tree being a chore especially since tree-sitter is used as the primary layer for parsing/AST manipulation in a custom compiler (i.e. not just syntax highlighting)

Needs

• traversing the AST for semantic analysis
• lowering to mlir/llvm
• generating AST transformers, UI debug, etc

Result

So hacked together a little proof of concept generator from the node-types.js + made some C++ adapters
caveat: it's hackishly ghetto so ignore the mess of code, especially the js. not a js dev

From a day of use, it's been a net positive

I liked the mlir architecture so applied the same model (ie the strong typed Tree-Sitter nodes are just adapters of the core TSNode so they can just be typecast back & forth, modulo special compiler settings of struct layout/packing)

Sample Use

    CSTree_o cstree = s_DSLSubsys->parseCSTree(srcbuf);
    Opdef_cst cstnde(cstree.root());
    for (Oprm_cst& oprm : cstnde.oprmblkNde().childNodes()) {
      prmblk.push_back(mbldr.prmbndAttr(as_strref(oprm.nameNde().src(srcbuf)),
        mlirGenEnum<EOprmFlag>(oprm.oprmetaNde().prmflagsNde()), mlirGenType(oprm.typeNde())));
    }
    OpdefOp opdefop = mbldr.opdefOp(as_strref(cstnde.evalFnNde().src(srcbuf)), prmblk);

Code

hacked generator + generated code for a custom c like grammar
https://gist.github.com/ikrima/3345769249993cafd7851390966089cb