Class: RubyLsp::Document::Utf8Scanner

Inherits:
Scanner
  • Object
show all
Defined in:
lib/ruby_lsp/document.rb

Overview

For the UTF-8 encoding, positions correspond to bytes

Constant Summary

Constants inherited from Scanner

Scanner::LINE_BREAK, Scanner::SURROGATE_PAIR_START

Instance Method Summary collapse

Constructor Details

#initialize(source) ⇒ Utf8Scanner

: (String source) -> void



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# File 'lib/ruby_lsp/document.rb', line 205

def initialize(source)
  super()
  @bytes = source.bytes #: Array[Integer]
  @character_length = 0 #: Integer
end

Instance Method Details

#find_char_position(position) ⇒ Object

: (Hash[Symbol, untyped] position) -> Integer



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# File 'lib/ruby_lsp/document.rb', line 213

def find_char_position(position)
  # Each group of bytes is a character. We advance based on the number of bytes to count how many full characters
  # we have in the requested offset
  until @current_line == position[:line]
    byte = @bytes[@pos] #: Integer?
    raise InvalidLocationError unless byte

    until LINE_BREAK == byte
      @pos += character_byte_length(byte)
      @character_length += 1
      byte = @bytes[@pos]
      raise InvalidLocationError unless byte
    end

    @pos += 1
    @character_length += 1
    @current_line += 1
  end

  # @character_length has the number of characters until the beginning of the line. We don't accumulate on it for
  # the character part because locating the same position twice must return the same value
  line_byte_offset = 0
  line_characters = 0

  while line_byte_offset < position[:character]
    byte = @bytes[@pos + line_byte_offset] #: Integer?
    raise InvalidLocationError unless byte

    line_byte_offset += character_byte_length(byte)
    line_characters += 1
  end

  @character_length + line_characters
end