gistfile1.coffee

# Match [ [1,2,3], [4,5,6], ... ]

class Matrix
  constructor(@rows) -> null

Matrix: [
  o 'LEFT_BRACKET (MatrixRow)+ RIGHT_BRACKET', ->
    new Matrix($2)
]

MatrixRow: [
  o 'COMMA MatrixRow', -> $2
  o 'LEFT_BRACKET (MatrixRowItem)+ RIGHT_BRACKET', -> $2
]

MatrixRowElement: [
  o 'NUMBER', -> $1
  o 'COMMA NUMBER', -> $2
]

I guess technically you could simplify the matrix rule to 'LEFT_BRACKET (MatrixRow)+ RIGHT_BRACKET'

Note that matrices like [, , , , , [, 2, 3] ] are also matched, which might or might not be desired.

This alternative approach might help.