class Prism::Location

This represents a location in the source.

Attributes

The length of this location in bytes.

A Source object that is used to determine more information from the given offset and length.

The byte offset from the beginning of the source where this location starts.

Public Class Methods

Create a new location object with the given source, start byte offset, and byte length.

# File lib/prism/parse_result.rb, line 305
def initialize(source, start_offset, length)
  @source = source
  @start_offset = start_offset
  @length = length

  # These are used to store comments that are associated with this location.
  # They are initialized to `nil` to save on memory when there are no
  # comments to be attached and/or the comment-related APIs are not used.
  @leading_comments = nil
  @trailing_comments = nil
end

Public Instance Methods

Returns true if the given other location is equal to this location.

# File lib/prism/parse_result.rb, line 493
def ==(other)
  Location === other &&
    other.start_offset == start_offset &&
    other.end_offset == end_offset
end

Join this location with the first occurrence of the string in the source that occurs after this location on the same line, and return the new location. This will raise an error if the string does not exist.

# File lib/prism/parse_result.rb, line 512
def adjoin(string)
  line_suffix = source.slice(end_offset, source.line_end(end_offset) - end_offset)

  line_suffix_index = line_suffix.byteindex(string)
  raise "Could not find #{string}" if line_suffix_index.nil?

  Location.new(source, start_offset, length + line_suffix_index + string.bytesize)
end

The end column in code units using the given cache to fetch or calculate the value.

# File lib/prism/parse_result.rb, line 478
def cached_end_code_units_column(cache)
  cache[end_offset] - cache[source.line_start(end_offset)]
end

The end offset from the start of the file in code units using the given cache to fetch or calculate the value.

# File lib/prism/parse_result.rb, line 414
def cached_end_code_units_offset(cache)
  cache[end_offset]
end

The start column in code units using the given cache to fetch or calculate the value.

# File lib/prism/parse_result.rb, line 454
def cached_start_code_units_column(cache)
  cache[start_offset] - cache[source.line_start(start_offset)]
end

The start offset from the start of the file in code units using the given cache to fetch or calculate the value.

# File lib/prism/parse_result.rb, line 392
def cached_start_code_units_offset(cache)
  cache[start_offset]
end

Returns a new location that is the result of chopping off the last byte.

# File lib/prism/parse_result.rb, line 351
def chop
  copy(length: length == 0 ? length : length - 1)
end

Returns all comments that are associated with this location (both leading and trailing comments).

# File lib/prism/parse_result.rb, line 341
def comments
  [*@leading_comments, *@trailing_comments]
end

Create a new location object with the given options.

# File lib/prism/parse_result.rb, line 346
def copy(source: self.source, start_offset: self.start_offset, length: self.length)
  Location.new(source, start_offset, length)
end

Implement the hash pattern matching interface for Location.

# File lib/prism/parse_result.rb, line 483
def deconstruct_keys(keys)
  { start_offset: start_offset, end_offset: end_offset }
end

The column number in characters where this location ends from the start of the line.

# File lib/prism/parse_result.rb, line 466
def end_character_column
  source.character_column(end_offset)
end

The character offset from the beginning of the source where this location ends.

# File lib/prism/parse_result.rb, line 403
def end_character_offset
  source.character_offset(end_offset)
end

The column number in code units of the given encoding where this location ends from the start of the line.

# File lib/prism/parse_result.rb, line 472
def end_code_units_column(encoding = Encoding::UTF_16LE)
  source.code_units_column(end_offset, encoding)
end

The offset from the start of the file in code units of the given encoding.

# File lib/prism/parse_result.rb, line 408
def end_code_units_offset(encoding = Encoding::UTF_16LE)
  source.code_units_offset(end_offset, encoding)
end

The column number in bytes where this location ends from the start of the line.

# File lib/prism/parse_result.rb, line 460
def end_column
  source.column(end_offset)
end

The line number where this location ends.

# File lib/prism/parse_result.rb, line 430
def end_line
  source.line(end_offset)
end

The byte offset from the beginning of the source where this location ends.

# File lib/prism/parse_result.rb, line 397
def end_offset
  start_offset + length
end

Returns a string representation of this location.

# File lib/prism/parse_result.rb, line 356
def inspect
  "#<Prism::Location @start_offset=#{@start_offset} @length=#{@length} start_line=#{start_line}>"
end

Returns a new location that stretches from this location to the given other location. Raises an error if this location is not before the other location or if they don’t share the same source.

# File lib/prism/parse_result.rb, line 502
def join(other)
  raise "Incompatible sources" if source != other.source
  raise "Incompatible locations" if start_offset > other.start_offset

  Location.new(source, start_offset, other.end_offset - start_offset)
end

Attach a comment to the leading comments of this location.

# File lib/prism/parse_result.rb, line 324
def leading_comment(comment)
  leading_comments << comment
end

These are the comments that are associated with this location that exist before the start of this location.

# File lib/prism/parse_result.rb, line 319
def leading_comments
  @leading_comments ||= []
end

Implement the pretty print interface for Location.

# File lib/prism/parse_result.rb, line 488
def pretty_print(q)
  q.text("(#{start_line},#{start_column})-(#{end_line},#{end_column})")
end

The source code that this location represents.

# File lib/prism/parse_result.rb, line 366
def slice
  source.slice(start_offset, length)
end

The source code that this location represents starting from the beginning of the line that this location starts on to the end of the line that this location ends on.

# File lib/prism/parse_result.rb, line 373
def slice_lines
  line_start = source.line_start(start_offset)
  line_end = source.line_end(end_offset)
  source.slice(line_start, line_end - line_start)
end

Returns all of the lines of the source code associated with this location.

# File lib/prism/parse_result.rb, line 361
def source_lines
  source.lines
end

The column number in characters where this location ends from the start of the line.

# File lib/prism/parse_result.rb, line 442
def start_character_column
  source.character_column(start_offset)
end

The character offset from the beginning of the source where this location starts.

# File lib/prism/parse_result.rb, line 381
def start_character_offset
  source.character_offset(start_offset)
end

The column number in code units of the given encoding where this location starts from the start of the line.

# File lib/prism/parse_result.rb, line 448
def start_code_units_column(encoding = Encoding::UTF_16LE)
  source.code_units_column(start_offset, encoding)
end

The offset from the start of the file in code units of the given encoding.

# File lib/prism/parse_result.rb, line 386
def start_code_units_offset(encoding = Encoding::UTF_16LE)
  source.code_units_offset(start_offset, encoding)
end

The column number in bytes where this location starts from the start of the line.

# File lib/prism/parse_result.rb, line 436
def start_column
  source.column(start_offset)
end

The line number where this location starts.

# File lib/prism/parse_result.rb, line 419
def start_line
  source.line(start_offset)
end

The content of the line where this location starts before this location.

# File lib/prism/parse_result.rb, line 424
def start_line_slice
  offset = source.line_start(start_offset)
  source.slice(offset, start_offset - offset)
end

Attach a comment to the trailing comments of this location.

# File lib/prism/parse_result.rb, line 335
def trailing_comment(comment)
  trailing_comments << comment
end

These are the comments that are associated with this location that exist after the end of this location.

# File lib/prism/parse_result.rb, line 330
def trailing_comments
  @trailing_comments ||= []
end