Class: Slim::Parser Private

Inherits:
Object
  • Object
show all
Includes:
Temple::Mixins::Options
Defined in:
lib/slim/parser.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Parses Slim code and transforms it to a Temple expression

Defined Under Namespace

Classes: SyntaxError

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Parser

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of Parser.



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# File 'lib/slim/parser.rb', line 29

def initialize(options = {})
  super
  @tab = ' ' * @options[:tabsize]
end

Instance Method Details

#compile(str) ⇒ Array

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Compile string to Temple expression

Parameters:

  • str (String) —

    Slim code

Returns:

  • (Array) —

    Temple expression representing the code



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# File 'lib/slim/parser.rb', line 38

def compile(str)
  lineno = 0
  result = [:multi]

  # Since you can indent however you like in Slim, we need to keep a list
  # of how deeply indented you are. For instance, in a template like this:
  #
  #   ! doctype     # 0 spaces
  #   html          # 0 spaces
  #    head         # 1 space
  #       title     # 4 spaces
  #
  # indents will then contain [0, 1, 4] (when it's processing the last line.)
  #
  # We uses this information to figure out how many steps we must "jump"
  # out when we see an de-indented line.
  indents = [0]

  # Whenever we want to output something, we'll *always* output it to the
  # last stack in this array. So when there's a line that expects
  # indentation, we simply push a new stack onto this array. When it
  # processes the next line, the content will then be outputted into that
  # stack.
  stacks = [result]

  # String buffer used for broken line (Lines ending with \)
  broken_line = nil

  # We have special treatment for text blocks:
  #
  #   |
  #     Hello
  #     World!
  #
  block_indent, in_comment, text_indent = nil, false, nil

  str.each_line do |line|
    lineno += 1

    # Remove the newline at the end
    line.chomp!

    # Handle broken lines
    if broken_line
      if broken_line[-1] == ?\\
        broken_line << "\n" << line
        next
      end
      broken_line = nil
    end

    if line.strip.empty?
      # This happens to be an empty line, so we'll just have to make sure
      # the generated code includes a newline (so the line numbers in the
      # stack trace for an exception matches the ones in the template).
      stacks.last << [:newline]
      next
    end

    # Figure out the indentation. Kinda ugly/slow way to support tabs,
    # but remember that this is only done at parsing time.
    indent = line[/^[ \t]*/].gsub("\t", @tab).size

    # Remove the indentation
    line.lstrip!

    # Handle blocks with multiple lines
    if block_indent
      if indent > block_indent
        # This line happens to be indented deeper (or equal) than the block start character (|, ', `, /).
        # This means that it's a part of the block.

        if !in_comment
          # The indentation of first line of the text block determines the text base indentation.
          newline = text_indent ? "\n" : ''
          text_indent ||= indent

          # The text block lines must be at least indented as deep as the first line.
          offset = indent - text_indent
          syntax_error! 'Unexpected text indentation', line, lineno if offset < 0

          # Generate the additional spaces in front.
          stacks.last << [:slim, :text, newline + (' ' * offset) + line]
        end

        stacks.last << [:newline]
        next
      end

      # It's guaranteed that we're now *not* in a block, because
      # the indent was less than the block start indent.
      block_indent = text_indent = nil
      in_comment = false
    end

    # If there's more stacks than indents, it means that the previous
    # line is expecting this line to be indented.
    expecting_indentation = stacks.size > indents.size

    if indent > indents.last
      # This line was actually indented, so we'll have to check if it was
      # supposed to be indented or not.
      syntax_error! 'Unexpected indentation', line, lineno unless expecting_indentation

      indents << indent
    else
      # This line was *not* indented more than the line before,
      # so we'll just forget about the stack that the previous line pushed.
      stacks.pop if expecting_indentation

      # This line was deindented.
      # Now we're have to go through the all the indents and figure out
      # how many levels we've deindented.
      while indent < indents.last
        indents.pop
        stacks.pop
      end

      # This line's indentation happens lie "between" two other line's
      # indentation:
      #
      #   hello
      #       world
      #     this      # <- This should not be possible!
      syntax_error! 'Malformed indentation', line, lineno if indents.last < indent
    end

    case line[0]
    when ?|, ?', ?/
      # Found a block.

      # We're now expecting the next line to be indented, so we'll need
      # to push a block to the stack.
      block = [:multi]
      stacks.last << (line[0] == ?' ? [:multi, block, [:slim, :text, ' ']] : block)
      stacks << block
      block_indent = indent

      in_comment = line[0] == ?/
      line.slice!(0)
      if !in_comment && !line.strip.empty?
        block << [:slim, :text, line.sub(/^( )/, '')]
        text_indent = block_indent + ($1 ? 2 : 1)
      end
    when ?-
      # Found a code block.
      # We expect the line to be broken or the next line to be indented.
      block = [:multi]
      broken_line = line[1..-1].strip
      stacks.last << [:slim, :control, broken_line, block]
      stacks << block
    when ?=
      # Found an output block.
      # We expect the line to be broken or the next line to be indented.
      block = [:multi]
      escape = line[1] != ?=
      broken_line = escape ? line[1..-1].strip : line[2..-1].strip
      stacks.last << [:slim, :output, escape, broken_line, block]
      stacks << block
    when ?!
      # Found a directive (currently only used for doctypes)
      stacks.last << [:slim, :directive, line[1..-1].strip]
    else
      if line =~ /^(\w+):\s*$/
        # Embedded template detected. It is treated as block.
        block = [:slim, :embedded, $1]
        stacks.last << [:newline] << block
        stacks << block
        block_indent = indent
        next
      else
        # Found a HTML tag.
        tag, block, broken_line, text_indent = parse_tag(line, lineno)
        stacks.last << tag
        stacks << block if block
        if text_indent
          block_indent = indent
          text_indent += indent
        end
      end
    end
    stacks.last << [:newline]
  end

  result
end