lib/haml_parser/indent_tracker.rb
# frozen_string_literal: true
require_relative 'error'
module HamlParser
class IndentTracker
class IndentMismatch < Error
attr_reader :current_level, :indent_levels
def initialize(current_level, indent_levels, lineno)
super("Unexpected indent level: #{current_level}: indent_level=#{indent_levels}", lineno)
@current_level = current_level
@indent_levels = indent_levels
end
end
class InconsistentIndent < Error
attr_reader :previous_size, :current_size
def initialize(previous_size, current_size, lineno)
super("Inconsistent indentation: #{current_size} spaces used for indentation, but the rest of the document was indented using #{previous_size} spaces.", lineno)
@previous_size = previous_size
@current_size = current_size
end
end
class HardTabNotAllowed < Error
def initialize(lineno)
super('Indentation with hard tabs are not allowed :-p', lineno)
end
end
def initialize(on_enter: nil, on_leave: nil)
@indent_levels = [0]
@on_enter = on_enter || lambda { |_level, _text| }
@on_leave = on_leave || lambda { |_level, _text| }
@comment_level = nil
end
def process(line, lineno)
if line.start_with?("\t")
raise HardTabNotAllowed.new(lineno)
end
indent, text = split(line)
indent_level = indent.size
unless text.empty?
track(indent_level, text, lineno)
end
[text, indent]
end
def split(line)
m = line.match(/\A( *)(.*)\z/)
[m[1], m[2]]
end
def finish
indent_leave(0, '', -1)
end
def current_level
@indent_levels.last
end
def enter_comment!
@comment_level = @indent_levels[-2]
end
def check_indent_level!(lineno)
if @indent_levels.size >= 3
previous_size = @indent_levels[-2] - @indent_levels[-3]
current_size = @indent_levels[-1] - @indent_levels[-2]
if previous_size != current_size
raise InconsistentIndent.new(previous_size, current_size, lineno)
end
end
end
private
def track(indent_level, text, lineno)
if indent_level > @indent_levels.last
indent_enter(indent_level, text, lineno)
elsif indent_level < @indent_levels.last
indent_leave(indent_level, text, lineno)
end
end
def indent_enter(indent_level, text, _lineno)
unless @comment_level
@indent_levels.push(indent_level)
@on_enter.call(indent_level, text)
end
end
def indent_leave(indent_level, text, lineno)
if @comment_level
if indent_level <= @comment_level
# finish comment mode
@comment_level = nil
else
# still in comment
return
end
end
while indent_level < @indent_levels.last
@indent_levels.pop
@on_leave.call(indent_level, text)
end
if indent_level != @indent_levels.last
raise IndentMismatch.new(indent_level, @indent_levels.dup, lineno)
end
end
end
end