require 'hemingway/build'
require 'hemingway/latex_nodes'
require "hemingway/block/block"
require "hemingway/footnote/footnote"
require "hemingway/math/math"
require "hemingway/special/special"
require "hemingway/symbol/symbol"
require "hemingway/tag/tag"
require "hemingway/text/text"

module Hemingway
  grammar Latex

    include Block
    include Footnote
    include Math
    include Special
    include Symbol
    include Tag
    include Text

    rule document
      entry
    end

    rule entry
      ( paragraph / last_paragraph )* <EntryNode>
    end

    # Example: These aren't the \n\n droids you're looking for \n\n.
    # Notes:
    #   - Okay so this is interesting. When you reference something with a * or
    #   a +, then you're creating a top level array-like structure that you'll
    #   have to dig past to get at the list. elements[0] refers to the array of
    #   tags or texts here.
    rule paragraph
      sequence:( content / footnote / !eop newline )* eop <ParagraphNode>
    end

    # The last paragraph in an entry need not end with \n\n. Because this
    # comes second in the ordered choice for entry, it will only be used
    # if a paragraph has concluded for some reason and there wasn't an eop
    # to consume. The only time I can imagine this happening would be at
    # the end of an entry.
    rule last_paragraph
      sequence:( content / footnote / !eop newline )+ eop? <ParagraphNode>
    end

    # Example: \tag{text} or just text or $\Delta$
    # Notes:
    #  - So I can define methods based on the ordered choice in the top
    #  level of this rule. Text is already its own thing though, so an html
    #  method need not be defined on it because alas, it already exists as
    #  defined in the text rule itself!
    rule content
      special / tag / block / math / text
    end

    # Treetop does not separate lexing from parsing. Must consume all input.
    rule whitespace
      ( " " / newline )+ <WhitespaceNode>
    end

    rule spaces
      ( " " )*
    end

    # End of paragraph. Originally this had a choice for EOF, but I can't
    # seem to find a good way for Treetop to process that. My workaround
    # strategy will be to append some newlines onto the end of the input
    # string.
    rule eop
      newline 2..
    end

    rule newline
      "\n" <NewlineNode>
    end

  end
end