Method start

src/tools/REPLTool/pyReplFactory.tsx:370–427

()

  }

  private async start(): Promise<void> {
    const rustHostPath = await resolvePythonReplHostExecutable()
    const child = rustHostPath
      ? spawn(rustHostPath, [], {
          cwd: process.cwd(),
          env: {
            ...process.env,
          },
          stdio: ['pipe', 'pipe', 'pipe'],
        })
      : spawn(resolvePythonExecutable(), [kernelAssetPath], {
          cwd: process.cwd(),
          env: {
            ...process.env,
            NCODE_PY_TMP_DIR: tmpdir(),
            NCODE_PY_REPL_PYTHON_MODULE_DIRS: '',
          },
          stdio: ['pipe', 'pipe', 'pipe'],
        })

    child.stdout.setEncoding('utf8')
    child.stderr.setEncoding('utf8')

    const stdoutReader = createInterface({
      input: child.stdout,
      crlfDelay: Infinity,
    })
    stdoutReader.on('line', line => {
      void this.handleKernelStdoutLine(line)
    })

    child.stderr.on('data', chunk => {
      const text = String(chunk)
      for (const line of text.split('\n')) {
        const trimmed = line.trim()
        if (!trimmed) continue
        this.stderrTail.push(trimmed)
        if (this.stderrTail.length > 20) {
          this.stderrTail.shift()
        }
      }
    })

    const handleExit = (reason: string) => {
      this.shutdown(reason)
    }
    child.on('error', error => {
      handleExit(error.message)
    })
    child.on('exit', (code, signal) => {
      handleExit(
        `Python REPL kernel exited${code !== null ? ` with code ${code}` : ''}${signal ? ` (${signal})` : ''}`,
      )
    })

    this.child = child
    this.stdoutReader = stdoutReader
  }