tex-convert-delimiters, rewrite by Erez

convert-delimiters.py

# Based on https://github.com/j2kun/tex-convert-delimiters/blob/master/convert-delimiters.py
# A response to https://jeremykun.com/2019/04/20/a-working-mathematicians-guide-to-parsing/

import sys
from lark import Lark, Transformer

lark = Lark(r'''
         tex: (mathmode_offset | mathmode_inline | TEXT)+

         mathmode_offset: OFFSETDOLLAR TEXT+ OFFSETDOLLAR | OFFSETOPEN TEXT+ OFFSETCLOSE
         mathmode_inline: INLINEOPEN TEXT+ INLINECLOSE | INLINE TEXT+ INLINE

         INLINE: "$"
         INLINEOPEN: "\\("
         INLINECLOSE: "\\)"
         OFFSETDOLLAR: "$$"
         OFFSETOPEN: "\\["
         OFFSETCLOSE: "\\]"

         TEXT: /[^\)\]$]+/s
         ''', start='tex', parser='lalr')


class T(Transformer):
    def mathmode_offset(self, children):
        return '\\[' + ''.join(children[1:-1]) + '\\]'

    def mathmode_inline(self, children):
        return '\\(' + ''.join(children[1:-1]) + '\\)'

    def tex(self, children):
        return ''.join(children)


input_text = sys.stdin.read()
parsed_doc = lark.parse(input_text)
print( T().transform(parsed_doc) )