Overhaul code (#106)

* Overhaul code:

* DRY prompt-toolkit and GNU readline initialization code
* Respect NO_COLOR environment setting
* Fix up style=None so that it doesn't show colors on In/Out
* Fix bugs in changing color styles
* Remove f5-f6 keybindings. It's too clumsy and hard to hook in.

Author: rocky

mathicsscript/__main__.py

@@ -27,7 +27,7 @@
 from mathics.core.evaluation import Evaluation, Output
 from mathics.core.expression import from_python
 from mathics.core.parser import MathicsFileLineFeeder
-from mathics.core.symbols import Symbol, SymbolFalse, SymbolTrue
+from mathics.core.symbols import Symbol, SymbolNull, SymbolFalse, SymbolTrue
 from mathics.core.systemsymbols import SymbolTeXForm
 from mathics.session import autoload_files
 
@@ -113,7 +113,10 @@ def ensure_settings():
     return settings_file
 
 
-def load_settings(shell):
+def load_settings_file(shell):
+    """
+    Read in or "autoload" Mathics3 code to initialize some settings.
+    """
     autoload_files(shell.definitions, get_srcdir(), "autoload")
     settings_file = ensure_settings()
     if settings_file == "":
@@ -182,6 +185,7 @@ def fmt_fun(query: Any) -> Any:
                 style = style.get_string_value()
                 if shell.terminal_formatter:
                     fmt = fmt_fun
+            shell.pygments_style = style or "None"
 
             evaluation = Evaluation(shell.definitions, output=TerminalOutput(shell))
 
@@ -200,7 +204,10 @@ def fmt_fun(query: Any) -> Any:
             ):
                 current_pos = GNU_readline.get_current_history_length()
                 for pos in range(last_pos, current_pos - 1):
-                    GNU_readline.remove_history_item(pos)
+                    try:
+                        GNU_readline.remove_history_item(pos)
+                    except ValueError:
+                        pass
                 wl_input = source_code.rstrip()
                 if unicode:
                     wl_input = replace_wl_with_plain_text(wl_input)
@@ -434,6 +441,10 @@ def main(
             f"Settings`{setting_name}", from_python(True if setting_value else False)
         )
 
+    if os.environ.get("NO_COLOR", False) and style not in (None, "None"):
+        print('Environment variable NO_COLOR set when "style" option given.')
+        print("NO_COLOR setting ignored.")
+
     if post_mortem:
         try:
             from trepan.post_mortem import post_mortem_excepthook
@@ -448,15 +459,20 @@ def main(
     readline = "none" if (code or file and not persist) else readline.lower()
     if readline == "prompt":
         shell = TerminalShellPromptToolKit(
-            definitions, style, completion, charset, prompt, edit_mode
+            definitions, completion, charset, prompt, edit_mode
         )
     else:
         want_readline = readline == "gnu"
         shell = TerminalShellGNUReadline(
-            definitions, style, want_readline, completion, charset, prompt
+            definitions, want_readline, completion, charset, prompt
         )
 
-    load_settings(shell)
+    load_settings_file(shell)
+    style_from_settings_file = definitions.get_ownvalue("Settings`$PygmentsStyle")
+    if style_from_settings_file is SymbolNull and style is None:
+        style = style_from_settings_file
+    shell.setup_pygments_style(style)
+
     if file:
         with open(file, "r") as ifile:
             feeder = MathicsFileLineFeeder(ifile)

mathicsscript/bindkeys.py

@@ -22,14 +22,11 @@
 from prompt_toolkit.enums import EditingMode
 from prompt_toolkit.key_binding import KeyBindings
 from prompt_toolkit.filters import Condition
-from prompt_toolkit.layout import Float, FloatContainer
-from prompt_toolkit.widgets import Dialog, Button, Label
 from sys import version_info
 import contextlib
 import pathlib
 import re
 
-from mathicsscript.termshell import ALL_PYGMENTS_STYLES
 from mathicsscript.settings import definitions
 from mathics.session import get_settings_value
 
@@ -149,36 +146,6 @@ def _group_autocomplete_toggle(event):
     app.group_autocomplete = not app.group_autocomplete
 
 
-# Add an additional key binding for toggling this flag.
-@bindings.add("f5")
-def _next_pygments_style(event):
-    """Set Pygments style to the next sytle in ALL_PYGMENTS_STYLE."""
-    app = event.app
-
-    try:
-        i = ALL_PYGMENTS_STYLES.index(app.pygments_style)
-    except ValueError:
-        pass
-    else:
-        i = (i + 1) % len(ALL_PYGMENTS_STYLES)
-        app.pygments_style = ALL_PYGMENTS_STYLES[i]
-
-
-# Add an additional key binding for toggling this flag.
-@bindings.add("f6")
-def _prev_pygments_style(event):
-    """Set Pygments style to the previous sytle in ALL_PYGMENTS_STYLE."""
-    app = event.app
-
-    try:
-        i = ALL_PYGMENTS_STYLES.index(app.pygments_style)
-    except ValueError:
-        pass
-    else:
-        i = (i - 1) % len(ALL_PYGMENTS_STYLES)
-        app.pygments_style = ALL_PYGMENTS_STYLES[i]
-
-
 def read_inputrc(read_init_file_fn: Callable, use_unicode: bool) -> None:
     """
     Read GNU Readline style inputrc

mathicsscript/termshell.py

@@ -5,14 +5,12 @@
 import os
 import os.path as osp
 import pathlib
-import sys
-from typing import Any, Optional, Union
+from typing import Any, Union
 
 import mathics_scanner.location
 
-from colorama import init as colorama_init
 from columnize import columnize
-from mathics.core.atoms import String, Symbol
+from mathics.core.atoms import Symbol
 from mathics.core.attributes import attribute_string_to_number
 from mathics.core.expression import Expression, from_python  # strip_context,
 from mathics.core.rules import Rule
@@ -32,7 +30,7 @@
 
 mma_lexer = MathematicaLexer()
 
-ALL_PYGMENTS_STYLES = list(get_all_styles())
+ALL_PYGMENTS_STYLES = list(get_all_styles()) + ["None"]
 
 color_scheme = TERMINAL_COLORS.copy()
 color_scheme[MToken.SYMBOL] = ("yellow", "ansibrightyellow")
@@ -79,8 +77,7 @@ class TerminalShellCommon(MathicsLineFeeder):
     def __init__(
         self,
         definitions,
-        style: Optional[str],
-        _: bool,
+        want_completion: bool,
         use_unicode: bool,
         prompt: bool,
     ):
@@ -94,38 +91,16 @@ def __init__(
         self.lineno = 0
         self.terminal_formatter = None
         self.prompt = prompt
+        self.want_completion = want_completion
 
-        colorama_init()
-        if style == "None":
-            self.terminal_formatter = None
-            self.incolors = self.outcolors = ["", "", "", ""]
-        else:
-            # self.incolors = ["\033[34m", "\033[1m", "\033[22m", "\033[39m"]
-            self.incolors = ["\033[32m", "\033[1m", "\033[22m", "\033[39m"]
-            self.outcolors = ["\033[31m", "\033[1m", "\033[22m", "\033[39m"]
-            if style is not None and not is_pygments_style(style):
-                style = None
-
-            if style is None:
-                dark_background = is_dark_background()
-                if dark_background:
-                    style = "inkpot"
-                else:
-                    style = "colorful"
-            try:
-                self.terminal_formatter = Terminal256Formatter(style=style)
-            except ClassNotFound:
-                print(f"Pygments style name '{style}' not found; No pygments style set")
-
-        self.pygments_style = style
         self.definitions = definitions
         self.definitions.set_ownvalue(
             "Settings`$PygmentsShowTokens", from_python(False)
         )
-        self.definitions.set_ownvalue("Settings`$PygmentsStyle", from_python(style))
         self.definitions.set_ownvalue("Settings`$UseUnicode", from_python(use_unicode))
         self.definitions.set_ownvalue(
-            "Settings`PygmentsStylesAvailable", from_python(ALL_PYGMENTS_STYLES)
+            "Settings`PygmentsStylesAvailable",
+            from_python(ALL_PYGMENTS_STYLES),
         )
 
         self.definitions.add_message(
@@ -149,20 +124,28 @@ def __init__(
             "Settings`PygmentsStylesAvailable",
             attribute_string_to_number["System`Locked"],
         )
+
         self.definitions.set_attribute(
             "Settings`$UseUnicode", attribute_string_to_number["System`Locked"]
         )
 
     def change_pygments_style(self, style: str):
         if not style or style == self.pygments_style:
             return False
+        if style == "None":
+            self.terminal_formatter = None
+            self.pygments_style = style
+            self.incolors = self.outcolors = ["", "", "", ""]
+            return True
         if is_pygments_style(style):
+            self.incolors = ["\033[32m", "\033[1m", "\033[22m", "\033[39m"]
+            self.outcolors = ["\033[31m", "\033[1m", "\033[22m", "\033[39m"]
             self.terminal_formatter = Terminal256Formatter(style=style)
             self.pygments_style = style
             return True
-        else:
-            print("Pygments style not changed")
-            return False
+
+        print("Pygments style not changed")
+        return False
 
     def empty(self):
         return False
@@ -189,19 +172,30 @@ def get_out_prompt(self, form: str) -> Union[str, Any]:
         default form, or the name of the Form which was used in output preceded by "//"
         """
         line_number = self.last_line_number
-        return "{2}Out[{3}{0}{4}]{5}{1}= ".format(line_number, form, *self.outcolors)
+        if self.is_styled:
+            return "{2}Out[{3}{0}{4}]{5}{1}= ".format(
+                line_number, form, *self.outcolors
+            )
+        else:
+            return f"Out[{line_number}]= "
 
     @property
     def in_prompt(self) -> Union[str, Any]:
         next_line_number = self.last_line_number + 1
         if self.lineno > 0:
             return " " * len(f"In[{next_line_number}]:= ")
-        else:
+        elif self.is_styled:
             return "{1}In[{2}{0}{3}]:= {4}".format(next_line_number, *self.incolors)
-            # if have_full_readline:
-            #     return "{1}In[{2}{0}{3}]:= {4}".format(next_line_number, *self.incolors)
-            # else:
-            #     return f"In[{next_line_number}]:= "
+        else:
+            return f"In[{next_line_number}]:= "
+
+    @property
+    def is_styled(self):
+        """
+        Returns True if a Pygments style (other than SymbolNull or "None" has been set.
+        """
+        style = self.definitions.get_ownvalue("Settings`$PygmentsStyle")
+        return not (style is SymbolNull or style.value == "None")
 
     @property
     def last_line_number(self) -> int:
@@ -213,7 +207,8 @@ def last_line_number(self) -> int:
     def out_callback(self, out):
         print(self.to_output(str(out), form=""))
 
-    def read_line(self, prompt, completer=None, use_html=None):
+    # noinspection PyUnusedLocal
+    def read_line(self, prompt, _completer=None, _use_html: bool = False):
         if self.using_readline:
             line = self.rl_read_line(prompt)
         else:
@@ -253,6 +248,19 @@ def print_result(
                     use_highlight = False
                 else:
                     out_str = '"' + out_str.replace('"', r"\"") + '"'
+
+            show_pygments_tokens = self.definitions.get_ownvalue(
+                "Settings`$PygmentsShowTokens"
+            ).to_python()
+            pygments_style = self.definitions.get_ownvalue(
+                "Settings`$PygmentsStyle"
+            ).get_string_value()
+            if pygments_style != self.pygments_style:
+                if not self.change_pygments_style(pygments_style):
+                    self.definitions.set_ownvalue(
+                        "Settings`$PygmentsStyle", String(self.pygments_style)
+                    )
+
             if eval_type == "System`Graph":
                 out_str = "-Graph-"
             elif self.terminal_formatter:  # pygmentize
@@ -273,7 +281,8 @@ def print_result(
                 if show_pygments_tokens:
                     print(list(lex(out_str, mma_lexer)))
                 if use_highlight:
-                    out_str = highlight(out_str, mma_lexer, self.terminal_formatter)
+                    if self.terminal_formatter is not None:
+                        out_str = highlight(out_str, mma_lexer, self.terminal_formatter)
             form = (
                 ""
                 if not hasattr(result, "form") or result.form is None
@@ -296,10 +305,49 @@ def rl_read_line(self, prompt):
     def reset_lineno(self):
         self.lineno = 0
 
+    def setup_pygments_style(self, style):
+        """Goes through what we need to do to setup or change a
+        Pygments style.
+        """
+        if (
+            isinstance(style, str)
+            and style.lower() == "none"
+            or style is None
+            and os.environ.get("NO_COLOR", False)
+        ):
+            style = "None"  # Canonicalize spelling
+            self.terminal_formatter = None
+            self.incolors = self.outcolors = ["", "", "", ""]
+        else:
+            # self.incolors = ["\033[34m", "\033[1m", "\033[22m", "\033[39m"]
+            self.incolors = ["\033[32m", "\033[1m", "\033[22m", "\033[39m"]
+            self.outcolors = ["\033[31m", "\033[1m", "\033[22m", "\033[39m"]
+            if style is not None and not is_pygments_style(style):
+                style = None
+
+            # If no style given, choose one based on the background.
+            if style is None:
+                dark_background = is_dark_background()
+                if dark_background:
+                    style = "inkpot"
+                else:
+                    style = "colorful"
+            try:
+                self.terminal_formatter = Terminal256Formatter(style=style)
+            except ClassNotFound:
+                print(f"Pygments style name '{style}' not found; No pygments style set")
+                style = "None"
+
+        self.definitions.set_ownvalue("Settings`$PygmentsStyle", from_python(style))
+        self.pygments_style = style
+
     def to_output(self, text: str, form: str) -> str:
         """
         Format an 'Out=' line that it lines after the first one indent properly.
         """
         line_number = self.last_line_number
-        newline = "\n" + " " * len(f"Out[{line_number}]{form}= ")
+        if self.is_styled:
+            newline = "\n" + " " * len(f"Out[{line_number}]{form}= ")
+        else:
+            newline = "\n" + " " * len(f"Out[{line_number}]= ")
         return newline.join(text.splitlines())

mathicsscript/termshell_gnu.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-#   Copyright (C) 2020-2022 Rocky Bernstein <[email protected]>
+#   Copyright (C) 2020-2022, 2025 Rocky Bernstein <[email protected]>
 
 import atexit
 import os
@@ -59,15 +59,12 @@ class TerminalShellGNUReadline(TerminalShellCommon):
     def __init__(
         self,
         definitions,
-        style: str,
         want_readline: bool,
         want_completion: bool,
         use_unicode: bool,
         prompt: bool,
     ):
-        super(TerminalShellGNUReadline, self).__init__(
-            definitions, style, want_completion, use_unicode, prompt
-        )
+        super().__init__(definitions, want_completion, use_unicode, prompt)
 
         # Try importing readline to enable arrow keys support etc.
         self.using_readline = False