Function streamDiffLines

core/edit/streamDiffLines.ts:77–190

(
  options: StreamDiffLinesPayload,
  llm: ILLM,
  abortController: AbortController,
  overridePrompt: ChatMessage[] | undefined,
  rulesToInclude: RuleWithSource[] | undefined,
)

}

export async function* streamDiffLines(
  options: StreamDiffLinesPayload,
  llm: ILLM,
  abortController: AbortController,
  overridePrompt: ChatMessage[] | undefined,
  rulesToInclude: RuleWithSource[] | undefined,
): AsyncGenerator<DiffLine> {
  const { type, prefix, highlighted, suffix, input, language } = options;

  // Strip common indentation for the LLM, then add back after generation
  let oldLines =
    highlighted.length > 0
      ? highlighted.split("\n")
      : // When highlighted is empty, we need to combine last line of prefix and first line of suffix to determine the line being edited
        [(prefix + suffix).split("\n")[prefix.split("\n").length - 1]];

  // But if that line is empty, we can assume we are insertion-only
  if (oldLines.length === 1 && oldLines[0].trim() === "") {
    oldLines = [];
  }

  // Defaults to creating an edit prompt
  // For apply can be overridden with simply apply prompt
  let prompt =
    overridePrompt ??
    (type === "apply"
      ? constructApplyPrompt(oldLines.join("\n"), options.newCode, llm)
      : constructEditPrompt(prefix, highlighted, suffix, llm, input, language));

  // Rules can be included with edit prompt
  // If any rules are present this will result in using chat instead of legacy completion
  const systemMessage =
    rulesToInclude || llm.baseChatSystemMessage
      ? getSystemMessageWithRules({
          availableRules: rulesToInclude ?? [],
          userMessage:
            typeof prompt === "string"
              ? ({
                  role: "user",
                  content: prompt,
                } as UserChatMessage)
              : (findLast(
                  prompt,
                  (msg) => msg.role === "user" || msg.role === "tool",
                ) as UserChatMessage | ToolResultChatMessage | undefined),
          baseSystemMessage: llm.baseChatSystemMessage,
          contextItems: [],
        }).systemMessage
      : undefined;

  if (systemMessage) {
    if (typeof prompt === "string") {
      prompt = [
        {
          role: "system",
          content: systemMessage,
        },
        {