Module errors

Contains some common error types.

Structs

• ExhaustedInput
  no options matched for rule
• NoMatch
  could not match literal
• Unexpected
  A canonical error for when a grammar simply finds something it doesn’t expect.
• UnexpectedEOF
  unexpected end of input
• UnexpectedMatch
  matched input unexpectedly
• UnmatchedInput
  expected input to match function