Represents a single line of code of a given source file
This object contains metadata about the line such as amount of indentation, if it is empty or not, and lexical data, such as if it has an ‘end` or a keyword in it.
Visibility of lines can be toggled off. Marking a line as invisible indicates that it should not be used for syntax checks. It’s functionally the same as commenting it out.
Example:
line = CodeLine.from_source("def foo\n").first line.number => 1 line.empty? # => false line.visible? # => true line.mark_invisible line.visible? # => false
When the code line is marked invisible we retain the original value of it’s line this is useful for debugging and for showing extra context
DisplayCodeWithLineNumbers will render all lines given to it, not just visible lines, it uses the original method to obtain them.
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 29
def self.from_source(source, lines: nil)
lines ||= source.lines
lex_array_for_line = LexAll.new(source: source, source_lines: lines).each_with_object(Hash.new { |h, k| h[k] = [] }) { |lex, hash| hash[lex.line] << lex }
lines.map.with_index do |line, index|
CodeLine.new(
line: line,
index: index,
lex: lex_array_for_line[index + 1]
)
end
end
Returns an array of CodeLine objects from the source string
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 42
def initialize(line:, index:, lex:)
@lex = lex
@line = line
@index = index
@original = line
@line_number = @index + 1
strip_line = line.dup
strip_line.lstrip!
@indent = if (@empty = strip_line.empty?)
line.length - 1 # Newline removed from strip_line is not "whitespace"
else
line.length - strip_line.length
end
set_kw_end
end
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 150
def <=>(other)
index <=> other.index
end
Comparison operator, needed for equality and sorting
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 115
def empty?
@empty
end
An ‘empty?` line is one that was originally left empty in the source code, while a “hidden” line is one that we’ve since marked as “invisible”
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 108
def hidden?
!visible?
end
Opposite or ‘visible?` (note: different than `empty?`)
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 172
def ignore_newline_not_beg?
@ignore_newline_not_beg
end
- Not stable API
-
Lines that have a ‘on_ignored_nl` type token and NOT a `BEG` type seem to be a good proxy for the ability to join multiple lines into one.
This predicate method is used to determine when those two criteria have been met.
The one known case this doesn’t handle is:
Ripper.lex <<~EOM a && b || c EOM
For some reason this introduces ‘on_ignore_newline` but with BEG type
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 72
def indent_index
@indent_index ||= [indent, index]
end
Used for stable sort via indentation level
Ruby’s sort is not “stable” meaning that when multiple elements have the same value, they are not guaranteed to return in the same order they were put in.
So when multiple code lines have the same indentation level, they’re sorted by their index value which is unique and consistent.
This is mostly needed for consistency of the test suite
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 87
def is_end?
@is_end
end
Returns true if the code line is determined to contain an ‘end` keyword
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 81
def is_kw?
@is_kw
end
Returns true if the code line is determined to contain a keyword that matches with an ‘end`
For example: ‘def`, `do`, `begin`, `ensure`, etc.
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 96
def mark_invisible
@line = ""
end
Used to hide lines
The search alorithm will group lines into blocks then if those blocks are determined to represent valid code they will be hidden
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 120
def not_empty?
!empty?
end
Opposite of ‘empty?` (note: different than `visible?`)
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 206
def set_kw_end
oneliner_count = 0
in_oneliner_def = nil
kw_count = 0
end_count = 0
@ignore_newline_not_beg = false
@lex.each do |lex|
kw_count += 1 if lex.is_kw?
end_count += 1 if lex.is_end?
if lex.type == :on_ignored_nl
@ignore_newline_not_beg = !lex.expr_beg?
end
if in_oneliner_def.nil?
in_oneliner_def = :ENDFN if lex.state.allbits?(Ripper::EXPR_ENDFN)
elsif lex.state.allbits?(Ripper::EXPR_ENDFN)
# Continue
elsif lex.state.allbits?(Ripper::EXPR_BEG)
in_oneliner_def = :BODY if lex.token == "="
elsif lex.state.allbits?(Ripper::EXPR_END)
# We found an endless method, count it
oneliner_count += 1 if in_oneliner_def == :BODY
in_oneliner_def = nil
else
in_oneliner_def = nil
end
end
kw_count -= oneliner_count
@is_kw = (kw_count - end_count) > 0
@is_end = (end_count - kw_count) > 0
end
Endless method detection
From github.com/ruby/irb/commit/826ae909c9c93a2ddca6f9cfcd9c94dbf53d44ab Detecting a “oneliner” seems to need a state machine. This can be done by looking mostly at the “state” (last value):
ENDFN -> BEG (token = '=' ) -> END
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 133
def to_s
line
end
Renders the given line
Also allows us to represent source code as an array of code lines.
When we have an array of code line elements calling ‘join` on the array will call `to_s` on each element, which essentially converts it back into it’s original source string.
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 184
def trailing_slash?
last = @lex.last
last&.type == :on_tstring_end
end
# File tmp/rubies/ruby-master/lib/syntax_suggest/code_line.rb, line 103
def visible?
!line.empty?
end
Means the line was marked as “invisible” Confusingly, “empty” lines are visible…they just don’t contain any source code other than a newline (“n”).