class Prism::Source
This represents a source of Ruby code that has been parsed. It is used in conjunction with locations to allow them to resolve line numbers and source ranges.
Attributes
The list of newline byte offsets in the source code.
The source code that this source object represents.
The line number where this source starts.
Public Class Methods
Create a new source object with the given source code and newline byte offsets. If no newline byte offsets are given, they will be computed from the source code.
# File prism/parse_result.rb, line 20 def initialize(source, start_line = 1, offsets = compute_offsets(source)) @source = source @start_line = start_line @offsets = offsets end
Public Instance Methods
Return the column number in characters for the given byte offset.
# File prism/parse_result.rb, line 55 def character_column(byte_offset) character_offset(byte_offset) - character_offset(line_start(byte_offset)) end
Return the character offset for the given byte offset.
# File prism/parse_result.rb, line 50 def character_offset(byte_offset) source.byteslice(0, byte_offset).length end
Return the column number for the given byte offset.
# File prism/parse_result.rb, line 45 def column(byte_offset) byte_offset - line_start(byte_offset) end
Binary search through the offsets to find the line number for the given byte offset.
# File prism/parse_result.rb, line 34 def line(byte_offset) start_line + find_line(byte_offset) end
Return the byte offset of the start of the line corresponding to the given byte offset.
# File prism/parse_result.rb, line 40 def line_start(byte_offset) offsets[find_line(byte_offset)] end
Perform a byteslice on the source code using the given byte offset and byte length.
# File prism/parse_result.rb, line 28 def slice(byte_offset, length) source.byteslice(byte_offset, length) end
Private Instance Methods
Find all of the newlines in the source code and return their byte offsets from the start of the string an array.
# File prism/parse_result.rb, line 83 def compute_offsets(code) offsets = [0] code.b.scan("\n") { offsets << $~.end(0) } offsets end
Binary search through the offsets to find the line number for the given byte offset.
# File prism/parse_result.rb, line 63 def find_line(byte_offset) left = 0 right = offsets.length - 1 while left <= right mid = left + (right - left) / 2 return mid if offsets[mid] == byte_offset if offsets[mid] < byte_offset left = mid + 1 else right = mid - 1 end end left - 1 end