class SyntaxSuggest::CodeLine

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

Constants

TRAILING_SLASH

Attributes

indent [R]

index [R]

lex [R]

line [R]

line_number [R]

number [R]

original [R]

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.

Public Class Methods

from_source (source, lines: nil)

Source

# File 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

new (line:, index:, lex:)

Source

# File 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

Public Instance Methods

<=> (other)

Source

# File lib/syntax_suggest/code_line.rb, line 150
def <=>(other)
  index <=> other.index
end

Comparison operator, needed for equality and sorting

empty? ()

Source

# File 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”

hidden? ()

Source

# File lib/syntax_suggest/code_line.rb, line 108
def hidden?
  !visible?
end

Opposite or ‘visible?` (note: different than `empty?`)

ignore_newline_not_beg? ()

Source

# File 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

indent_index ()

Source

# File 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

is_end? ()

Source

# File 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

is_kw? ()

Source

# File 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.

mark_invisible ()

Source

# File 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

not_empty? ()

Source

# File lib/syntax_suggest/code_line.rb, line 120
def not_empty?
  !empty?
end

Opposite of ‘empty?` (note: different than `visible?`)

to_s ()

Source

# File 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.

trailing_slash? ()

Source

# File lib/syntax_suggest/code_line.rb, line 183
def trailing_slash?
  last = @lex.last

  # Older versions of prism diverged slightly from Ripper in compatibility mode
  case last&.type
  when :on_sp
    last.token == TRAILING_SLASH
  when :on_tstring_end
    true
  else
    false
  end
end

Determines if the given line has a trailing slash

lines = CodeLine.from_source(<<~EOM)
  it "foo" \
EOM
expect(lines.first.trailing_slash?).to eq(true)

visible? ()

Source

# File 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”).

Private Instance Methods

set_kw_end ()

Source

# File lib/syntax_suggest/code_line.rb, line 205
        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