Add Semantic Prompt support to multiline continuation lines (xonsh#5065)

* fix: match the main return type to avoid a style class concat type error

Error: can only concatenate str (not "_TokenType") to str in prompt_toolkit/formatted_text/base.py, line 94, in <listcomp>
    [(style + " " + item_style, *rest) for item_style, *rest in result]

* feat: support semantic prompt sequences for the multiline prompt

* Ignore .python-version

* doc: add News item

* doc: add description for the new multiline prompt env vars

.gitignore

@@ -41,6 +41,8 @@ include/
 venv/
 .venv*/
 
+# Python project version files
+.python-version
 
 # Mac
 .DS_Store

news/multil.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* Add support for `Semantic Prompt <https://gitlab.freedesktop.org/Per_Bothner/specifications/blob/master/proposals/semantic-prompts.md>`_ for line continuations in multiline prompts via two environment variables: ``$MULTILINE_PROMPT_PRE`` (e.g., ``\x01\x1b]133;P;k=c\x07\x02``), and ``$MULTILINE_PROMPT_POS`` (e.g., ``\x01\x1b]133;B\x07\x02``) that are inserted before/after each continuation line 'dots' block to mark input
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>

xonsh/environ.py

@@ -1386,6 +1386,30 @@ class PromptSetting(Xettings):
  "Prompt text for 2nd+ lines of input, may be str or function which "
  "returns a str.",
  )
+ MULTILINE_PROMPT_PRE = Var(
+ is_string_or_callable,
+ ensure_string,
+ ensure_string,
+ "",
+ "Indicator inserted before the line continuation marks set "
+ "in ``$MULTILINE_PROMPT``. Can be used to mark the start of "
+ "a semantic continuation prompt "
+ "(see `Semantic Prompts <https://gitlab.freedesktop.org/Per_Bothner/specifications/blob/master/proposals/semantic-prompts.md>`_ "
+ "or `WezTerm <https://wezfurlong.org/wezterm/shell-integration.html>`_ "
+ "for more details). May be str or function which returns a str.",
+ )
+ MULTILINE_PROMPT_POS = Var(
+ is_string_or_callable,
+ ensure_string,
+ ensure_string,
+ "",
+ "Indicator inserted after the line continuation marks set "
+ "in ``$MULTILINE_PROMPT``. Can be used to mark the end of "
+ "a semantic continuation prompt and the beginning of user input "
+ "(see `Semantic Prompts <https://gitlab.freedesktop.org/Per_Bothner/specifications/blob/master/proposals/semantic-prompts.md>`_ "
+ "or `WezTerm <https://wezfurlong.org/wezterm/shell-integration.html>`_ "
+ "for more details). May be str or function which returns a str.",
+ )
  PRETTY_PRINT_RESULTS = Var.with_default(
  True,
  'Flag for "pretty printing" return values.',

xonsh/ptk_shell/shell.py

@@ -468,10 +468,27 @@ def continuation_tokens(self, width, line_number, is_soft_wrap=False):
  dots = dots() if callable(dots) else dots
  if not dots:
  return ""
+ prefix = XSH.env.get(
+ "MULTILINE_PROMPT_PRE", ""
+ ) # e.g.: '\x01\x1b]133;P;k=c\x07\x02'
+ suffix = XSH.env.get(
+ "MULTILINE_PROMPT_POS", ""
+ ) # e.g.: '\x01\x1b]133;B\x07\x02'
+ is_affix = any(x for x in [prefix, suffix])
+ if is_affix:
+ prefixtoks = tokenize_ansi(PygmentsTokens(self.format_color(prefix)))
+ suffixtoks = tokenize_ansi(PygmentsTokens(self.format_color(suffix)))
+ # [('class:pygments.color.reset',''), ('[ZeroWidthEscape]','\x1b]133;P;k=c\x07')]
+ # [('class:pygments.color.reset',''), ('[ZeroWidthEscape]','\x1b]133;B\x07')]
+
  basetoks = self.format_color(dots)
  baselen = sum(len(t[1]) for t in basetoks)
  if baselen == 0:
- return [(Token, " " * (width + 1))]
+ toks = [(Token, " " * (width + 1))]
+ if is_affix: # to convert ↓ classes to str to allow +
+ return prefixtoks + to_formatted_text(PygmentsTokens(toks)) + suffixtoks
+ else:
+ return PygmentsTokens(toks)
  toks = basetoks * (width // baselen)
  n = width % baselen
  count = 0
@@ -488,7 +505,10 @@ def continuation_tokens(self, width, line_number, is_soft_wrap=False):
  if n <= count:
  break
  toks.append((Token, " ")) # final space
- return PygmentsTokens(toks)
+ if is_affix:
+ return prefixtoks + to_formatted_text(PygmentsTokens(toks)) + suffixtoks
+ else:
+ return PygmentsTokens(toks)
 
  def format_color(self, string, hide=False, force_string=False, **kwargs):
  """Formats a color string using Pygments. This, therefore, returns