ruby/doc/strscan/methods/getch.md

call-seq: getch -> character or nil

Returns the next (possibly multibyte) character, if available:

• If the [position][2] is at the beginning of a character:

  • Returns the character.
  • Increments the [character position][7] by 1.
  • Increments the [byte position][2] by the size (in bytes) of the character.

  scanner = StringScanner.new(HIRAGANA_TEXT)
  scanner.string                                # => "こんにちは"
  [scanner.getch, scanner.pos, scanner.charpos] # => ["こ", 3, 1]
  [scanner.getch, scanner.pos, scanner.charpos] # => ["ん", 6, 2]
  [scanner.getch, scanner.pos, scanner.charpos] # => ["に", 9, 3]
  [scanner.getch, scanner.pos, scanner.charpos] # => ["ち", 12, 4]
  [scanner.getch, scanner.pos, scanner.charpos] # => ["は", 15, 5]
  [scanner.getch, scanner.pos, scanner.charpos] # => [nil, 15, 5]
  

• If the [position][2] is within a multi-byte character (that is, not at its beginning), behaves like #get_byte (returns a 1-byte character):

  scanner.pos = 1
  [scanner.getch, scanner.pos, scanner.charpos] # => ["\x81", 2, 2]
  [scanner.getch, scanner.pos, scanner.charpos] # => ["\x93", 3, 1]
  [scanner.getch, scanner.pos, scanner.charpos] # => ["ん", 6, 2]
  

• If the [position][2] is at the end of the [stored string][1], returns nil and does not modify the positions:

  scanner.terminate
  [scanner.getch, scanner.pos, scanner.charpos] # => [nil, 15, 5]