Class: Kotoshu::Readers::FileReader

Inherits:
Object
  • Object
show all
Defined in:
lib/kotoshu/readers/file_reader.rb

Overview

Base reader class for reading files line by line.

This class provides:

  • Line-by-line reading with line numbers

  • BOM (byte-order mark) handling

  • Comment stripping

  • Empty line filtering

Examples:

Basic usage

reader = FileReader.new('file.aff', 'UTF-8')
reader.each do |line_no, line|
  puts "#{line_no}: #{line}"
end

Direct Known Subclasses

StringReader

Constant Summary collapse

UTF8_BOM =

BOM (byte-order mark) for UTF-8

"\xEF\xBB\xBF".freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path, encoding = 'UTF-8') ⇒ FileReader

Create a new file reader.

Parameters:

  • path (String) —

    Path to the file

  • encoding (String) (defaults to: 'UTF-8') —

    File encoding (default: ‘UTF-8’)



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# File 'lib/kotoshu/readers/file_reader.rb', line 44

def initialize(path, encoding = 'UTF-8')
  @path = path
  @encoding = encoding
  @line_no = 0
  @file = nil
  @iterator = nil
  reset_io
end

Instance Attribute Details

#encoding ⇒ String (readonly)

Returns The encoding.

Returns:

  • (String) —

    The encoding



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# File 'lib/kotoshu/readers/file_reader.rb', line 32

def encoding
  @encoding
end

#line_no ⇒ Integer (readonly)

Returns Current line number.

Returns:

  • (Integer) —

    Current line number



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# File 'lib/kotoshu/readers/file_reader.rb', line 35

def line_no
  @line_no
end

#path ⇒ String (readonly)

Returns The file path.

Returns:

  • (String) —

    The file path



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# File 'lib/kotoshu/readers/file_reader.rb', line 29

def path
  @path
end

Instance Method Details

#close ⇒ Object

Close the file.



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# File 'lib/kotoshu/readers/file_reader.rb', line 111

def close
  @file&.close
  @file = nil
end

#each {|Integer, String| ... } ⇒ Enumerator

Iterate over lines.

Yields:

  • (Integer, String) —

    Line number and line content

Returns:

  • (Enumerator) —

    If no block given



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# File 'lib/kotoshu/readers/file_reader.rb', line 67

def each
  return enum_for(:each) unless block_given?

  @iterator.each { |line_no, line| yield(line_no, line) }
end

#has_next? ⇒ Boolean

Check if there are more lines.

Returns:

  • (Boolean) —

    True if there are more lines



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# File 'lib/kotoshu/readers/file_reader.rb', line 83

def has_next?
  peek
  true
rescue StopIteration
false
end

#next ⇒ Array<Integer, String>

Get next line.

Returns:

  • (Array<Integer, String>) —

    Line number and content



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# File 'lib/kotoshu/readers/file_reader.rb', line 100

def next
  @iterator.next
end

#peek ⇒ Array<Integer, String>

Peek at next line without consuming it.

Returns:

  • (Array<Integer, String>) —

    Next line number and content



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# File 'lib/kotoshu/readers/file_reader.rb', line 93

def peek
  @iterator.peek
end

#reset ⇒ Object

Reset the reader to the beginning.



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# File 'lib/kotoshu/readers/file_reader.rb', line 105

def reset
  @line_no = 0
  reset_io
end

#reset_encoding(new_encoding) ⇒ Object

Reset encoding and reopen file.

Parameters:

  • new_encoding (String) —

    New encoding



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# File 'lib/kotoshu/readers/file_reader.rb', line 56

def reset_encoding(new_encoding)
  @encoding = new_encoding
  @line_no = 0
  @file&.close
  reset_io
end

#to_a ⇒ Array<Array<Integer, String>>

Get all lines as an array.

Returns:

  • (Array<Array<Integer, String>>) —

    Array of [line_no, line] pairs



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# File 'lib/kotoshu/readers/file_reader.rb', line 76

def to_a
  @iterator.to_a
end