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terminal_style

What it is​

A small helper module for a SPARQL terminal UI that:

  • Renders queries, results, and messages using Rich (tables, panels, syntax highlighting).
  • Collects interactive user input with basic multiline support.
  • Persists command/query history to ~/.sparql_terminal_history on exit.

Public API​

Functions:

  • set_terminal_title(): Sets the terminal title to "SPARQL Terminal" (Windows via title, Unix-like via escape sequence).
  • print_query_result(result): Pretty-prints SPARQL query results (expects an RDFLib SPARQLResult-like object with .vars and iterable rows).
  • print_query_error(error): Prints an error in a red Rich panel.
  • print_system_message(text): Prints a yellow "System" panel message.
  • print_query(query): Displays a SPARQL query with syntax highlighting (sparql, monokai) in a panel.
  • clear_screen(): Clears the console (rich.Console.clear()).
  • print_welcome_message(): Sets terminal title and prints usage/help text.
  • print_divider(): Prints a dim horizontal divider across current console width.
  • preinput(): Captures current readline buffer into a module-level current_input.
  • get_user_input(): Reads interactive input:
    • Special commands: exit, help, clear (returned lowercase).
    • Multiline: collects lines until:
      • a line ends with ;, or
      • an empty line is entered after content exists.
    • Strips a trailing ; from the final query.
    • On EOFError/KeyboardInterrupt: prints a message and returns "exit".

History persistence:

  • save_history(): Writes command_history to ~/.sparql_terminal_history.
  • load_history(): Loads command_history from ~/.sparql_terminal_history if present.

Module-level objects/state (used by the API):

  • console: rich.console.Console() instance used for all I/O.
  • command_history: list of past commands/queries (loaded at import time).
  • history_index, current_input: globals (note: history_index is not used in current logic).

Configuration/Dependencies​

  • Dependencies:
    • rich (Console, Panel, Syntax, Text, Table, ROUNDED)
    • Standard library: os, platform, readline, atexit
  • Files:
    • History file path: ~/.sparql_terminal_history
  • Import-time side effects:
    • load_history() is called on import.
    • save_history() is registered via atexit.register(...).

Usage​

from naas_abi.apps.sparql_terminal import terminal_style as ts

ts.print_welcome_message()

while True:
    user_text = ts.get_user_input()
    if user_text == "exit":
        break
    if user_text == "clear":
        ts.clear_screen()
        continue
    if user_text == "help":
        ts.print_welcome_message()
        continue

    ts.print_query(user_text)
    # Execute query elsewhere and pass results to:
    # ts.print_query_result(result)

Caveats​

  • get_user_input() relies on rich.Console.input() and readline; history navigation behavior depends on the runtime environment and terminal support.
  • History saving/loading silently ignores all exceptions (failures won’t be reported).
  • Multiline termination is simplistic: a trailing ; ends input and is removed from the final query string.