nimforum mirror - Tree-sitter compatible parser generator

YesDrX (orginal) [2025-12-23T04:30:47+01:00] view original

Hi,

I made a tree-sitter compatible parser genrator: https://github.com/YesDrX/nim-treestand

Examples:

import tree-sitter grammar.js


import treestand
import std/os

# Import grammar at compile-time - generates parser directly in your module
importGrammar(currentSourcePath.parentDir / "grammar.js")

when isMainModule:
  # Use the auto-generated parser
  let tree = parseJson("""{"key": "value", "number": 42}""")
  echo tree

2. build your grammar


import treestand
import std/os

# Define grammar using clean DSL syntax
ts_grammar "mathGrammar":
  # Entry point - one or more statements
  program     <- +statement
  
  # Choice between different statement types
  statement   <- assignment | expression
  
  # Named fields for AST nodes
  assignment  <- (target: identifier) * eq * (value: expression)
  
  # Precedence and associativity
  expression  <- number | binary_op | parens
  binary_op   <- ((left: expression) * op * (right: expression)) ^ 1
  parens      <- lparen * expression * rparen
  
  # Lexical tokens - use token() wrapper
  identifier  <- token(re"[a-zA-Z_]\w*")
  number      <- token(re"\d+")
  op          <- token(re"[+\-*/]")
  eq          <- token("=")
  lparen      <- token("(")
  rparen      <- token(")")
  
  # Keywords using set syntax
  keyword     <- {"if", "else", "while"}
  
  # Configuration - skip whitespace
  extras      = token(re"\s+")

buildGrammar(mathGrammar)

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13584 :: Tree-sitter compatible parser generator