class Prism::Source

# File lib/prism/parse_result.rb, line 13
def self.for(source, start_line = 1, offsets = [])
  if source.ascii_only?
    ASCIISource.new(source, start_line, offsets)
  elsif source.encoding == Encoding::BINARY
    source.force_encoding(Encoding::UTF_8)

    if source.valid_encoding?
      new(source, start_line, offsets)
    else
      # This is an extremely niche use case where the file is marked as
      # binary, contains multi-byte characters, and those characters are not
      # valid UTF-8. In this case we'll mark it as binary and fall back to
      # treating everything as a single-byte character. This _may_ cause
      # problems when asking for code units, but it appears to be the
      # cleanest solution at the moment.
      source.force_encoding(Encoding::BINARY)
      ASCIISource.new(source, start_line, offsets)
    end
  else
    new(source, start_line, offsets)
  end
end

# File lib/prism/parse_result.rb, line 46
def initialize(source, start_line = 1, offsets = [])
  @source = source
  @start_line = start_line # set after parsing is done
  @offsets = offsets # set after parsing is done
end

# File lib/prism/parse_result.rb, line 108
def character_column(byte_offset)
  character_offset(byte_offset) - character_offset(line_start(byte_offset))
end

# File lib/prism/parse_result.rb, line 103
def character_offset(byte_offset)
  (source.byteslice(0, byte_offset) or raise).length
end

# File lib/prism/parse_result.rb, line 136
def code_units_cache(encoding)
  CodeUnitsCache.new(source, encoding)
end

# File lib/prism/parse_result.rb, line 142
def code_units_column(byte_offset, encoding)
  code_units_offset(byte_offset, encoding) - code_units_offset(line_start(byte_offset), encoding)
end

# File lib/prism/parse_result.rb, line 124
def code_units_offset(byte_offset, encoding)
  byteslice = (source.byteslice(0, byte_offset) or raise).encode(encoding, invalid: :replace, undef: :replace)

  if encoding == Encoding::UTF_16LE || encoding == Encoding::UTF_16BE
    byteslice.bytesize / 2
  else
    byteslice.length
  end
end

# File lib/prism/parse_result.rb, line 98
def column(byte_offset)
  byte_offset - line_start(byte_offset)
end

# File lib/prism/parse_result.rb, line 147
def deep_freeze
  source.freeze
  offsets.freeze
  freeze
end

# File lib/prism/parse_result.rb, line 64
def encoding
  source.encoding
end

# File lib/prism/parse_result.rb, line 81
def line(byte_offset)
  start_line + find_line(byte_offset)
end

# File lib/prism/parse_result.rb, line 93
def line_end(byte_offset)
  offsets[find_line(byte_offset) + 1] || source.bytesize
end

# File lib/prism/parse_result.rb, line 87
def line_start(byte_offset)
  offsets[find_line(byte_offset)]
end

# File lib/prism/parse_result.rb, line 69
def lines
  source.lines
end

# File lib/prism/parse_result.rb, line 58
def replace_offsets(offsets)
  @offsets.replace(offsets)
end

# File lib/prism/parse_result.rb, line 53
def replace_start_line(start_line)
  @start_line = start_line
end

# File lib/prism/parse_result.rb, line 75
def slice(byte_offset, length)
  source.byteslice(byte_offset, length) or raise
end

# File lib/prism/parse_result.rb, line 157
def find_line(byte_offset)
  index = offsets.bsearch_index { |offset| offset > byte_offset } || offsets.length
  index - 1
end