Class: Lmt::Tangle::Tangler

Inherits:
Object
  • Object
show all
Defined in:
lib/lmt/lmt.rb

Defined Under Namespace

Classes: ConditionalProcessor

Instance Method Summary collapse

Constructor Details

#initialize(input, include_path = []) ⇒ Tangler

Returns a new instance of Tangler.



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# File 'lib/lmt/lmt.rb', line 125

def initialize(input, include_path = [])
  @include_path = include_path
  @extension_context = Context.new()
  @extension_context.filters = {
    'ruby_escape' => LineFilter.new do |line|
      line.dump[1..-2]
    end,
    'double_quote' => LineFilter.new do |line|
      before_white = /^\s*/.match(line)[0]
      after_white = /\s*$/.match(line)[0]
      "#{before_white}\"#{line.strip}\"#{after_white}"
    end,
    'add_comma' => LineFilter.new do |line|
      before_white = /^\s*/.match(line)[0]
      after_white = /\s*$/.match(line)[0]
      "#{before_white}#{line.strip},#{after_white}"
    end,
    'indent_continuation' => Filter.new do |lines|
      [lines[0], *lines[1..-1].map {|l| "  #{l}"}]
    end,
    'indent_lines' => LineFilter.new do |line|
      "  #{line}"
    end
  }
  @input = input
  @block = ""
  @blocks = {}
  @tangled = false
end

Instance Method Details

#apply_filters(strings, filters) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 263

def apply_filters(strings, filters)
  filters.map do |filter_name|
    filters_map[filter_name]
  end.inject(strings) do |strings, filter|
    filter.filter(strings)
  end
end

#expand_macros(lines, depth = 0) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 252

def expand_macros(lines, depth = 0)
  throw "too deep macro expansion {depth}" if depth > 1000
  lines.map do |line|
    begin
      expand_macro_on_line(line, depth)
    rescue Exception => e
      raise Exception, "Failed to process line: #{line}", e.backtrace
    end
  end.flatten(1)
end

#handle_extensions_and_conditionals(lines) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 192

def handle_extensions_and_conditionals(lines)
  extension_expression = /^(\s*)``` ruby !/
  condition_processor = ConditionalProcessor.new(@extension_context)
  extension_exit_expression = /```/
  in_extension_block = false
  current_extension_block = []

  other_lines = lines.lazy
    .find_all do |line|
      condition_processor.should_output(line)
    end.find_all do |line|
      unless in_extension_block
        in_extension_block = line =~ extension_expression
        if in_extension_block
          current_extension_block = []
        end
        !in_extension_block
      else
        in_extension_block = !(line =~ extension_exit_expression)
        if in_extension_block
          current_extension_block << line
        else
          @extension_context.get_binding.eval(current_extension_block.join)
        end
        false
      end
    end.force

  condition_processor.check_block_balance()

  other_lines
end

#include_includes(lines, current_file = @input, depth = 0) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 172

def include_includes(lines, current_file = @input, depth = 0)
  raise "too many includes" if depth > 1000
  include_exp = /^!\s+include\s+\[.*\]\((.*)\)\s*$/
  include_path_exp = /^!\s+include-path\s+(.*)\s*$/
  lines.map do |line|
    include_path_match = include_path_exp.match(line)
    include_match = include_exp.match(line)
    if include_path_match
      path = resolve_include(include_path_match[1], current_file)[0]
      @include_path << path
      [line]
    elsif include_match
      file = resolve_include(include_match[1], current_file)[0]
      include_includes(read_file(file), file, depth + 1)
    else
      [line]
    end
  end.flatten(1)
end

#parse_blocks(lines) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 225

def parse_blocks(lines)
  code_block_exp = /^(\s*)``` ?([\w]*) ?(=?)([-\w]*)?/
  in_block = false
  blocks = lines.find_all do |line|
    in_block = !in_block if line =~ code_block_exp
    in_block
  end.slice_before do |line|
    code_block_exp =~ line
  end.map do |(header, *rest)|
    white_space, language, replacement_mark, name = code_block_exp.match(header)[1..-1]
    [name, replacement_mark, rest]
  end.group_by do |(name, _, _)|
    name
  end.transform_values do |bodies|
    last_replacement_index = get_last_replacement_index(bodies)
    bodies[last_replacement_index..-1].map { |(_, _, body)| body}
      .flatten(1)
  end.transform_values do |body_lines|
    body_lines[-1] = body_lines[-1].chomp if body_lines[-1]
    body_lines
  end
  throw "Missing code fence" if in_block
  main = blocks[""]
  blocks.delete("")
  [main, blocks]
end

#read_file(file) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 166

def read_file(file)
  File.open(file, 'r') do |f|
    f.readlines
  end
end

#tangle ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 155

def tangle()
  contents =  handle_extensions_and_conditionals(
      include_includes(read_file(@input)))
  @block, @blocks = @extension_context.parse_hook(*parse_blocks(contents))
  if @block
    @block = expand_macros(@block)
    @block = unescape_double_parens(@block)
  end
  @tangled = true
end

#unescape_double_parens(block) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 270

def unescape_double_parens(block)
  block.map do |l|
    l = l.gsub("\\⦅", "⦅")
    l = l.gsub("\\⦆", "⦆")
    l
  end
end

#write(output) ⇒ Object 



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# File 'lib/lmt/lmt.rb', line 278

def write(output)
  tangle() unless @tangled
  if @block
    fout = File.open(output, 'w')
    @block.each {|line| fout << line}
  end
end