adding Exit as an alias of Quit (#998)

This fixes #996. It seems that the rule for `Exit` was not loaded
together with `Quit`.

---------

Co-authored-by: R. Bernstein <[email protected]>

mathics/builtin/evaluation.py

@@ -1,14 +1,16 @@
 # -*- coding: utf-8 -*-
+"""Evaluation Control
 
 
+Mathics3 takes an expression that it is given, and evaluates it. Built \
+into the evaluation are primitives that allow finer control over the \
+process of evaluation in cases where it is needed.
+"""
+
 from mathics.core.atoms import Integer
 from mathics.core.attributes import A_HOLD_ALL, A_HOLD_ALL_COMPLETE, A_PROTECTED
 from mathics.core.builtin import Builtin, Predefined
-from mathics.core.evaluation import (
-    MAX_RECURSION_DEPTH,
-    Evaluation,
-    set_python_recursion_limit,
-)
+from mathics.core.evaluation import MAX_RECURSION_DEPTH, set_python_recursion_limit
 
 
 class RecursionLimit(Predefined):
@@ -303,38 +305,3 @@ class Sequence(Builtin):
     summary_text = (
         "a sequence of arguments that will automatically be spliced into any function"
     )
-
-
-class Quit(Builtin):
-    """
-    <url>:WMA link:https://reference.wolfram.com/language/ref/Quit.html</url>
-
-    <dl>
-      <dt>'Quit'[]
-      <dd> Terminates the Mathics session.
-
-      <dt>'Quit[$n$]'
-      <dd> Terminates the mathics session with exit code $n$.
-    </dl>
-
-    <dl>
-      <dt>'Exit'[]
-      <dd> Terminates the Mathics session.
-
-      <dt>'Exit[$n$]'
-      <dd> Terminates the mathics session with exit code $n$.
-    </dl>
-
-    """
-
-    rules = {
-        "Exit[n___]": "Quit[n]",
-    }
-    summary_text = "terminate the session"
-
-    def eval(self, evaluation: Evaluation, n):
-        "%(name)s[n___]"
-        exitcode = 0
-        if isinstance(n, Integer):
-            exitcode = n.get_int_value()
-        raise SystemExit(exitcode)

mathics/builtin/kernel_sessions.py

@@ -0,0 +1,101 @@
+# -*- coding: utf-8 -*-
+"Kernel Sessions"
+
+from mathics.core.atoms import Integer
+from mathics.core.attributes import A_LISTABLE, A_PROTECTED
+from mathics.core.builtin import Builtin
+from mathics.core.evaluation import Evaluation
+
+
+class Out(Builtin):
+    """
+    <url>:WMA: https://reference.wolfram.com/language/ref/$Out</url>
+    <dl>
+      <dt>'%$k$' or 'Out[$k$]'
+      <dd>gives the result of the $k$th input line.
+
+      <dt>'%'
+      <dd>gives the last result.
+
+      <dt>''%%'
+      <dd>gives the result before the previous input line.
+    </dl>
+
+    >> 42
+     = 42
+    >> %
+     = 42
+    >> 43;
+    >> %
+     = 43
+    >> 44
+     = 44
+    >> %1
+     = 42
+    >> %%
+     = 44
+    >> Hold[Out[-1]]
+     = Hold[%]
+    >> Hold[%4]
+     = Hold[%4]
+    >> Out[0]
+     = Out[0]
+
+    #> 10
+     = 10
+    #> Out[-1] + 1
+     = 11
+    #> Out[] + 1
+     = 12
+    """
+
+    attributes = A_LISTABLE | A_PROTECTED
+
+    rules = {
+        "Out[k_Integer?Negative]": "Out[$Line + k]",
+        "Out[]": "Out[$Line - 1]",
+        "MakeBoxes[Out[k_Integer?((-10 <= # < 0)&)],"
+        "    f:StandardForm|TraditionalForm|InputForm|OutputForm]": r'StringJoin[ConstantArray["%%", -k]]',
+        "MakeBoxes[Out[k_Integer?Positive],"
+        "    f:StandardForm|TraditionalForm|InputForm|OutputForm]": r'"%%" <> ToString[k]',
+    }
+    summary_text = "result of the Kth input line"
+
+
+class Quit(Builtin):
+    """
+    <url>:WMA link:https://reference.wolfram.com/language/ref/Quit.html</url>
+
+    <dl>
+      <dt>'Quit'[]
+      <dd> Terminates the Mathics session.
+
+      <dt>'Quit[$n$]'
+      <dd> Terminates the mathics session with exit code $n$.
+    </dl>
+    'Quit' is the same thing as 'Exit'.
+    """
+
+    summary_text = "terminate the session"
+
+    def eval(self, evaluation: Evaluation, n):
+        "%(name)s[n___]"
+        exitcode = 0
+        if isinstance(n, Integer):
+            exitcode = n.get_int_value()
+        raise SystemExit(exitcode)
+
+
+class Exit(Quit):
+    """
+    <url>:WMA link:https://reference.wolfram.com/language/ref/Exit.html</url>
+
+    <dl>
+      <dt>'Exit'[]
+      <dd> Terminates the Mathics session.
+
+      <dt>'Exit[$n$]'
+      <dd> Terminates the mathics session with exit code $n$.
+      'Exit' is the same thing as 'Quit'.
+    </dl>
+    """

mathics/builtin/mainloop.py

@@ -222,56 +222,3 @@ class Line(Builtin):
 
     name = "$Line"
     summary_text = "current line number"
-
-
-class Out(Builtin):
-    """
-    <url>:WMA: https://reference.wolfram.com/language/ref/$Out</url>
-    <dl>
-      <dt>'Out[$k$]'
-      <dt>'%$k$'
-      <dd>gives the result of the $k$th input line.
-
-      <dt>'%', '%%', etc.
-      <dd>gives the result of the previous input line, of the line before the previous input line, etc.
-    </dl>
-
-    >> 42
-     = 42
-    >> %
-     = 42
-    >> 43;
-    >> %
-     = 43
-    >> 44
-     = 44
-    >> %1
-     = 42
-    >> %%
-     = 44
-    >> Hold[Out[-1]]
-     = Hold[%]
-    >> Hold[%4]
-     = Hold[%4]
-    >> Out[0]
-     = Out[0]
-
-    #> 10
-     = 10
-    #> Out[-1] + 1
-     = 11
-    #> Out[] + 1
-     = 12
-    """
-
-    attributes = A_LISTABLE | A_PROTECTED
-
-    rules = {
-        "Out[k_Integer?Negative]": "Out[$Line + k]",
-        "Out[]": "Out[$Line - 1]",
-        "MakeBoxes[Out[k_Integer?((-10 <= # < 0)&)],"
-        "    f:StandardForm|TraditionalForm|InputForm|OutputForm]": r'StringJoin[ConstantArray["%%", -k]]',
-        "MakeBoxes[Out[k_Integer?Positive],"
-        "    f:StandardForm|TraditionalForm|InputForm|OutputForm]": r'"%%" <> ToString[k]',
-    }
-    summary_text = "result of the Kth input line"