This project is about testing Left Recursion support in OMeta/JS.
It is inspired by Warth, A. and Douglass, J.R. and Millstein, T.
"Pacrkat Parsers Can Support Left Recursion"

I have also checked PyMeta implementation and it supports direct LR,
but not indirect one.
Reading the code of OMeta/JS direct LR is supported as shown in
first example.

This is direct left recursion:
ometa directLR {
  expr = expr '-' num
       | num,
  num  = digit
}

input = '1-2-3'
directLR.matchAll(input, 'expr')


Here is an indirect Left Recursion which is not supported:
ometa indirectLR {
  expr = xxx:a '-' num:b end -> [a,'-',b]
       | num end,
  num  = digit,
  xxx  = expr
}

indirectLR.matchAll(input, 'expr')


ometa lr {
  lr = lr '1' | '1'
}

input = '11111'
lr.matchAll(input, 'lr')


ometa rr {
  rr = '1' rr | '1'
}

input = '11111'
rr.matchAll(input, 'rr')



ometa lr1 {
  lr1 = x1 '1' | '1',
  x1 = lr1
}

input = '11111'
lr1.matchAll(input, 'lr1')



ometa lr2 {
  lr2 = x2 '1' | '1',
  x2 = x1,
  x1 = lr2
}

input = '11111'
lr2.matchAll(input, 'lr2')