Module: MilkTea::LSP::Server::ServerInlayHints

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

Instance Method Summary collapse

Instance Method Details

#collect_function_defs(ast_node) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 217

def collect_function_defs(ast_node)
  results = []
  case ast_node
  when Array
    ast_node.each { |n| results.concat(collect_function_defs(n)) }
  when AST::SourceFile
    ast_node.declarations.each do |d|
      case d
      when AST::FunctionDef
        results << d
      when AST::ExtendingBlock
        results.concat(d.methods)
      end
    end
  end
  results
end

#collect_inferred_return_hints(facts, start_line, start_char, end_line, end_char) ⇒ Object 



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

def collect_inferred_return_hints(facts, start_line, start_char, end_line, end_char)
  hints = []
  collect_function_defs(facts.ast).each do |func|
    next unless func.return_type.nil?
    next unless position_in_range?(func.line - 1, func.column - 1, start_line, start_char, end_line, end_char)

    binding = resolve_function_binding(facts, func)
    next unless binding
    next unless binding.respond_to?(:type) && binding.type.respond_to?(:return_type)

    return_type = binding.type.return_type
    next unless return_type

    display_type = describe_type_for_hint(return_type)
    next unless display_type
    next if display_type == "void"

    label = "-> #{display_type}"
    hints << {
      position: { line: func.line - 1, character: func.column - 1 + func.name.length },
      label: label,
      kind: 1,
      paddingRight: false
    }
  end
  hints
end

#collect_inferred_type_hints(facts, start_line, start_char, end_line, end_char) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 108

def collect_inferred_type_hints(facts, start_line, start_char, end_line, end_char)
  hints = []
  collect_local_decls(facts.ast).each do |decl|
    next unless decl.name && decl.name != '_'
    next unless decl.type.nil?
    next unless position_in_range?(decl.line - 1, decl.column - 1, start_line, start_char, end_line, end_char)

    display_type = resolved_decl_type_detail(decl, facts)
    next unless display_type

    hints << {
      position: { line: decl.line - 1, character: decl.column - 1 + decl.name.length },
      label: ": #{display_type}",
      kind: 1,
      paddingRight: false
    }
  end
  hints
end

#collect_local_decls(ast_node) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 185

def collect_local_decls(ast_node)
  results = []
  case ast_node
  when Array
    ast_node.each { |n| results.concat(collect_local_decls(n)) }
  when AST::SourceFile
    ast_node.declarations.each { |d| results.concat(collect_local_decls(d)) }
  when AST::FunctionDef
    results.concat(collect_local_decls(ast_node.body)) if ast_node.body
  when AST::MethodDef
    results.concat(collect_local_decls(ast_node.body)) if ast_node.body
  when AST::ExtendingBlock
    ast_node.methods.each { |m| results.concat(collect_local_decls(m)) }
  when AST::IfStmt
    ast_node.branches.each { |b| results.concat(collect_local_decls(b.body)) }
    results.concat(collect_local_decls(ast_node.else_body)) if ast_node.else_body
  when AST::MatchStmt
    ast_node.arms.each { |a| results.concat(collect_local_decls(a.body)) }
  when AST::ForStmt
    results.concat(collect_local_decls(ast_node.body))
  when AST::WhileStmt
    results.concat(collect_local_decls(ast_node.body))
  when AST::UnsafeStmt
    results.concat(collect_local_decls(ast_node.body))
  when AST::LocalDecl
    results << ast_node
  when AST::VariantArm
    # no body
  end
  results
end

#collect_parameter_name_hints(tokens, facts, start_line, start_char, end_line, end_char) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 39

def collect_parameter_name_hints(tokens, facts, start_line, start_char, end_line, end_char)
  hints = []
  i = 0
  while i < tokens.length - 1
    callee = tokens[i]
    next_tok = tokens[i + 1]
    prev_tok = i > 0 ? tokens[i - 1] : nil

    binding = nil
    lparen_index = nil

    if callee.type == :identifier && prev_tok&.type != :function
      # Direct function call: func(...)
      if next_tok&.type == :lparen
        binding = facts.functions[callee.lexeme]
        binding ||= facts.imports.each_value.find { |mod| mod.functions.key?(callee.lexeme) }&.functions&.dig(callee.lexeme)
        lparen_index = i + 1
      elsif next_tok&.type == :dot
        member = tokens[i + 2]
        member_lparen = tokens[i + 3]
        if member&.type == :identifier && member_lparen&.type == :lparen
          # Module-qualified call: mod.func(...)
          mod_binding = facts.imports[callee.lexeme]
          if mod_binding
            binding = mod_binding.functions[member.lexeme]
          else
            # Instance method call: obj.method(...) or Type.static(...)
            receiver_type = resolve_dot_receiver_value_type(facts, callee.lexeme, callee.line, callee.column)
            receiver_type ||= facts.types[callee.lexeme]
            unless receiver_type
              receiver_type = facts.imports.each_value.find { |mod| mod.types.key?(callee.lexeme) }&.types&.dig(callee.lexeme)
            end
            if receiver_type
              methods = methods_for_receiver_type(facts, receiver_type)
              binding = methods[member.lexeme] || methods["static:#{member.lexeme}"]
            end
          end
          lparen_index = i + 3
        end
      end
    end

    if binding && lparen_index
      arg_starts, closing_index = collect_call_argument_starts(tokens, lparen_index)
      params_list = binding.respond_to?(:type) ? binding.type.params : []

      arg_starts.each_with_index do |arg_tok, index|
        break if index >= params_list.length
        next unless position_in_range?(arg_tok.line - 1, arg_tok.column - 1, start_line, start_char, end_line, end_char)
        next if self_describing_argument_expression?(tokens, arg_tok)
        param_name = params_list[index].name
        next if arg_tok.type == :identifier && arg_tok.lexeme == param_name

        hints << {
          position: { line: arg_tok.line - 1, character: arg_tok.column - 1 },
          label: "#{params_list[index].name}: ",
          kind: 2,
          paddingRight: true
        }
      end

      i = closing_index if closing_index
    end

    i += 1
  end
  hints
end

#describe_type_for_hint(type) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 235

def describe_type_for_hint(type)
  return nil unless type

  type.to_s
rescue StandardError
  nil
end

#handle_inlay_hint(params) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 7

def handle_inlay_hint(params)
  uri = params.dig('textDocument', 'uri')
  range = params['range'] || {}
  start_line = range.dig('start', 'line') || 0
  start_char = range.dig('start', 'character') || 0
  end_line = range.dig('end', 'line') || 0
  end_char = range.dig('end', 'character') || 0

  content = @workspace.get_content(uri)
  return [] if content && skip_expensive_work_reason(uri, content)

  facts = @workspace.get_facts(uri)
  tokens = @workspace.get_tokens(uri)
  return [] unless facts && tokens

  hints = []

  # Parameter-name hints at call sites
  hints.concat(collect_parameter_name_hints(tokens, facts, start_line, start_char, end_line, end_char))

  # Type annotation hints for inferred locals
  hints.concat(collect_inferred_type_hints(facts, start_line, start_char, end_line, end_char))

  # Return type hints for inferred return types
  hints.concat(collect_inferred_return_hints(facts, start_line, start_char, end_line, end_char))

  hints
rescue StandardError => e
  warn "Error in inlayHint handler: #{e.message}"
  []
end

#resolve_function_binding(facts, func) ⇒ Object 



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 171

def resolve_function_binding(facts, func)
  name = func.name
  if func.is_a?(AST::MethodDef)
    facts.methods.each_value do |methods|
      binding = methods[name] || methods["static:#{name}"]
      return binding if binding
    end
    return nil
  end

  facts.functions[name] ||
    facts.imports.each_value.find { |mod| mod.functions.key?(name) }&.functions&.dig(name)
end

#resolved_decl_type_detail(decl, facts) ⇒ Object

Resolves the declared type of an inferred local from semantic facts so the hint reflects flow refinement (let/var ... else:, ?-propagation).



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# File 'lib/milk_tea/lsp/server/inlay_hints.rb', line 130

def resolved_decl_type_detail(decl, facts)
  resolution = facts.respond_to?(:binding_resolution) ? facts.binding_resolution : nil
  return nil unless resolution

  binding_id = resolution.declaration_binding_ids[decl.object_id]
  return nil unless binding_id

  type = resolution.binding_types[binding_id]
  return nil if type.is_a?(Types::Error)

  short_type_detail(type)
end