Pretty print

mathics/builtin/arithfns/basic.py

@@ -15,6 +15,7 @@
     IntegerM1,
     Number,
     RationalOneHalf,
+    String,
 )
 from mathics.core.attributes import (
     A_FLAT,
@@ -34,11 +35,21 @@
 )
 from mathics.core.evaluation import Evaluation
 from mathics.core.expression import Expression
-from mathics.core.symbols import Symbol, SymbolNull, SymbolPower, SymbolTimes
+from mathics.core.list import ListExpression
+from mathics.core.symbols import (
+    Symbol,
+    SymbolHoldForm,
+    SymbolNull,
+    SymbolPower,
+    SymbolTimes,
+    SymbolTrue,
+)
 from mathics.core.systemsymbols import (
     SymbolBlank,
     SymbolComplexInfinity,
     SymbolIndeterminate,
+    SymbolInfix,
+    SymbolLeft,
     SymbolPattern,
     SymbolSequence,
 )
@@ -144,7 +155,7 @@ class Divide(InfixOperator):
     expected_args = 2
 
     formats = {
-        (("InputForm", "OutputForm"), "Divide[x_, y_]"): (
+        ("InputForm", "Divide[x_, y_]"): (
             'Infix[{HoldForm[x], HoldForm[y]}, "/", 400, Left]'
         ),
     }
@@ -160,6 +171,24 @@ class Divide(InfixOperator):
 
     summary_text = "divide a number"
 
+    def format_outputform(self, x, y, evaluation):
+        "(OutputForm,): Divide[x_, y_]"
+        use_2d = (
+            evaluation.definitions.get_ownvalues("System`$Use2DOutputForm")[0].replace
+            is SymbolTrue
+        )
+        if not use_2d:
+            return Expression(
+                SymbolInfix,
+                ListExpression(
+                    Expression(SymbolHoldForm, x), Expression(SymbolHoldForm, y)
+                ),
+                String("/"),
+                Integer(400),
+                SymbolLeft,
+            )
+        return None
+
 
 class Minus(PrefixOperator):
     """
@@ -350,10 +379,21 @@ class Power(InfixOperator, MPMathFunction):
             Expression(SymbolPattern, Symbol("x"), Expression(SymbolBlank)),
             RationalOneHalf,
         ): "HoldForm[Sqrt[x]]",
-        (("InputForm", "OutputForm"), "x_ ^ y_"): (
+        (("InputForm",), "x_ ^ y_"): (
             'Infix[{HoldForm[x], HoldForm[y]}, "^", 590, Right]'
         ),
-        ("", "x_ ^ y_"): (
+        (("OutputForm",), "x_ ^ y_"): (
+            "If[$Use2DOutputForm, "
+            "Superscript[HoldForm[x], HoldForm[y]], "
+            'Infix[{HoldForm[x], HoldForm[y]}, "^", 590, Right]]'
+        ),
+        (
+            (
+                "StandardForm",
+                "TraditionalForm",
+            ),
+            "x_ ^ y_",
+        ): (
             "PrecedenceForm[Superscript[PrecedenceForm[HoldForm[x], 590],"
             "  HoldForm[y]], 590]"
         ),

mathics/builtin/forms/print.py

@@ -20,7 +20,7 @@
 from mathics.core.symbols import SymbolFalse, SymbolTrue
 from mathics.core.systemsymbols import SymbolInputForm, SymbolOutputForm
 from mathics.format.box.makeboxes import is_print_form_callback
-from mathics.format.form import render_input_form, render_output_form
+from mathics.format.form import render_input_form
 
 sort_order = "mathics.builtin.forms.general-purpose-forms"
 
@@ -258,7 +258,21 @@ def eval_makeboxes_outputform(expr: BaseElement, evaluation: Evaluation, **kwarg
     Build a 2D representation of the expression using only keyboard characters.
     """
 
-    text_outputform = str(render_output_form(expr, evaluation, **kwargs))
+    from mathics.builtin.box.layout import InterpretationBox
+    from mathics.format.form.outputform import render_output_form
+    from mathics.format.render.prettyprint import render_2d_text
+
+    if (
+        evaluation.definitions.get_ownvalues("System`$Use2DOutputForm")[0].replace
+        is SymbolTrue
+    ):
+        text_outputform = str(render_2d_text(expr, evaluation, **{"2d": True}))
+
+        if "\n" in text_outputform:
+            text_outputform = "\n" + text_outputform
+    else:  # 1D
+        text_outputform = str(render_output_form(expr, evaluation, **kwargs))
+
     pane = PaneBox(String('"' + text_outputform + '"'))
     return InterpretationBox(
         pane, Expression(SymbolOutputForm, expr), **{"System`Editable": SymbolFalse}

mathics/builtin/forms/variables.py

@@ -5,7 +5,12 @@
 
 """
 
-from mathics.core.attributes import A_LOCKED, A_PROTECTED, A_READ_PROTECTED
+from mathics.core.attributes import (
+    A_LOCKED,
+    A_NO_ATTRIBUTES,
+    A_PROTECTED,
+    A_READ_PROTECTED,
+)
 from mathics.core.builtin import Builtin, Predefined
 from mathics.core.list import ListExpression
 
@@ -179,3 +184,35 @@ class PrintForms_(Predefined):
 
     def evaluate(self, evaluation):
         return ListExpression(*evaluation.definitions.printforms)
+
+
+class Use2DOutputForm_(Predefined):
+    r"""
+    <dl>
+      <dt>'$Use2DOutputForm'
+      <dd>internal variable that controls if 'OutputForm[expr]' is shown \
+          in one line (standard Mathics behavior) or \
+          or in a prettyform-like multiline output (the standard way in WMA).
+          The default value is 'False', keeping the standard Mathics behavior.
+    </dl>
+
+    >> $Use2DOutputForm
+     = False
+    >> OutputForm[a^b]
+     = a ^ b
+    >> $Use2DOutputForm = True; OutputForm[a ^ b]
+     =  
+     .  b
+     . a 
+
+    Setting the variable back to False go back to the normal behavior:
+    >> $Use2DOutputForm = False; OutputForm[a ^ b]
+     = a ^ b
+    """
+
+    attributes = A_NO_ATTRIBUTES
+    name = "$Use2DOutputForm"
+    rules = {
+        "$Use2DOutputForm": "False",
+    }
+    summary_text = "use the 2D OutputForm"

mathics/doc/doc_entries.py

@@ -10,7 +10,6 @@
 import logging
 import re
 from abc import ABC
-from os import getenv
 from typing import TYPE_CHECKING, Callable, Dict, List, Optional, Sequence, Tuple
 
 from mathics.core.evaluation import Message, Print, _Out