Class: CachedNestedFileReader

Inherits:
Object
  • Object
show all
Includes:
Exceptions
Defined in:
lib/cached_nested_file_reader.rb

Overview

The CachedNestedFileReader class provides functionality to read file lines with the ability to process ‘#import filename’ directives. When such a directive is encountered in a file, the corresponding ‘filename’ is read and its contents are inserted at that location. This class caches read files to avoid re-reading the same file multiple times. It allows clients to read lines with or without providing a block.

Instance Method Summary collapse

Methods included from Exceptions

error_handler, warn_format

Constructor Details

#initialize(import_pattern: /^ *#import (.+)$/) ⇒ CachedNestedFileReader

Returns a new instance of CachedNestedFileReader.



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# File 'lib/cached_nested_file_reader.rb', line 23

def initialize(import_pattern: /^ *#import (.+)$/)
  @file_cache = {}
  @import_pattern = import_pattern
end

Instance Method Details

#error_handler(name = '', opts = {}) ⇒ Object 



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# File 'lib/cached_nested_file_reader.rb', line 28

def error_handler(name = '', opts = {})
  Exceptions.error_handler(
    "CachedNestedFileReader.#{name} -- #{$!}",
    opts
  )
end

#readlines(filename, depth = 0, context: '', import_paths: nil, &block) ⇒ Object 



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# File 'lib/cached_nested_file_reader.rb', line 42

def readlines(filename, depth = 0, context: '', import_paths: nil, &block)
  if @file_cache.key?(filename)
    @file_cache[filename].each(&block) if block
    return @file_cache[filename]
  end

  directory_path = File.dirname(filename)
  processed_lines = []
  File.readlines(filename, chomp: true).each.with_index do |line, ind|
    if Regexp.new(@import_pattern) =~ line
      name_strip = $~[:name].strip
      included_file_path = if name_strip =~ %r{^/}
                             name_strip
                           elsif import_paths
                             find_files(name_strip, import_paths + [directory_path])&.first
                           else
                             File.join(directory_path, name_strip)
                           end

      processed_lines += readlines(included_file_path, depth + 1,
                                   context: "#{filename}:#{ind + 1}",
                                   import_paths: import_paths,
                                   &block)
    else
      nested_line = NestedLine.new(line, depth)
      processed_lines.push(nested_line)
      block&.call(nested_line)
    end
  end

  @file_cache[filename] = processed_lines
rescue Errno::ENOENT
  # Exceptions.error_handler('readlines', { abort: true })
  warn_format('readlines', "No such file -- #{filename} @@ #{context}", { abort: true })
end

#warn_format(name, message, opts = {}) ⇒ Object 



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# File 'lib/cached_nested_file_reader.rb', line 35

def warn_format(name, message, opts = {})
  Exceptions.warn_format(
    "CachedNestedFileReader.#{name} -- #{message}",
    opts
  )
end