Module: MilkTea::LSP::Server::ServerFoldingRange

Included in:
MilkTea::LSP::Server
Defined in:
lib/milk_tea/lsp/server/folding_range.rb

Constant Summary collapse

BLOCK_START_PATTERN = 
/\A(public\s+)?(async\s+)?(editable\s+)?(function|struct|enum|flags|variant|union|interface|if|while|for|match|unsafe|extending|defer)\b/
CONTINUATION_KEYWORDS = 
%w[else elif when].freeze

Instance Method Summary collapse

Instance Method Details

#block_start?(stripped) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 115

def block_start?(stripped)
  return false unless stripped.end_with?(":") || stripped == ":"

  stripped.match?(BLOCK_START_PATTERN) && !CONTINUATION_KEYWORDS.any? { |kw| stripped.start_with?(kw) }
end

#compute_block_folds(lines, folds) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 28

def compute_block_folds(lines, folds)
  stack = [] # [[start_line, indent], ...]
  last_indent = 0

  lines.each_with_index do |line, line_num|
    stripped = line.lstrip
    next if stripped.empty?

    indent = line.length - stripped.length
    stripped_no_comment = strip_comment(stripped)

    if indent < last_indent
      while stack.any? && stack.last[1] >= indent
        start_line, = stack.pop
        folds << folding_range(start_line, line_num - 1) if line_num - 1 > start_line
      end
    end

    if continuation_start?(stripped_no_comment)
      if stack.any? && stack.last[1] == indent
        start_line, = stack.pop
        folds << folding_range(start_line, line_num - 1) if line_num - 1 > start_line
      end
      stack << [line_num, indent]
    elsif block_start?(stripped_no_comment)
      stack << [line_num, indent]
    end

    last_indent = indent
  end

  last_line = lines.length - 1
  while stack.any?
    start_line, = stack.pop
    folds << folding_range(start_line, last_line) if last_line > start_line
  end
end

#compute_comment_folds(lines, folds) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 97

def compute_comment_folds(lines, folds)
  comment_start = nil

  lines.each_with_index do |line, line_num|
    stripped = line.lstrip
    if stripped.start_with?("#>") && comment_start.nil?
      comment_start = line_num
    elsif stripped.include?("<#") && comment_start
      folds << {
        startLine: comment_start,
        endLine: line_num,
        kind: "comment",
      }
      comment_start = nil
    end
  end
end

#compute_import_folds(lines, folds) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 66

def compute_import_folds(lines, folds)
  import_start = nil

  lines.each_with_index do |line, line_num|
    stripped = line.lstrip
    if stripped.start_with?("import ")
      import_start ||= line_num
    else
      if import_start && line_num - 1 > import_start
        folds << {
          startLine: import_start,
          endLine: line_num - 1,
          kind: "imports",
        }
      end
      import_start = nil
    end
  end

  return unless import_start

  last_line = lines.length - 1
  return unless last_line > import_start

  folds << {
    startLine: import_start,
    endLine: last_line,
    kind: "imports",
  }
end

#continuation_start?(stripped) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 121

def continuation_start?(stripped)
  return false unless stripped.end_with?(":") || stripped == ":"

  CONTINUATION_KEYWORDS.any? { |kw| stripped.start_with?(kw) }
end

#folding_range(start_line, end_line) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 143

def folding_range(start_line, end_line)
  { startLine: start_line, endLine: end_line }
end

#handle_folding_range(params) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 11

def handle_folding_range(params)
  text_document = params["textDocument"]
  uri = text_document["uri"]
  content = @workspace.get_content(uri)
  return [] unless content

  lines = content.split("\n", -1)
  folds = []

  compute_block_folds(lines, folds)
  compute_import_folds(lines, folds)
  compute_comment_folds(lines, folds)
  trim_trailing_blank_lines(folds, lines)

  folds
end

#strip_comment(line) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 127

def strip_comment(line)

  idx = line.index(" #")
  idx ? line[0...idx] : line
end

#trim_trailing_blank_lines(folds, lines) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/folding_range.rb', line 133

def trim_trailing_blank_lines(folds, lines)
  folds.each do |fold|
    end_line = fold[:endLine]
    while end_line > fold[:startLine] && lines[end_line].strip.empty?
      end_line -= 1
    end
    fold[:endLine] = end_line
  end
end