formatting OutputForm

outputform and fullform following the WMA formatting steps

mathics/builtin/box/layout.py

@@ -188,6 +188,33 @@ def eval_display(boxexpr, evaluation):
         return boxexpr.elements[0]
 
 
+class PaneBox(BoxExpression):
+    """
+    <url>
+    :WMA link:
+    https://reference.wolfram.com/language/ref/InterpretationBox.html</url>
+
+    <dl>
+      <dt>'PaneBox[expr]'
+      <dd> is a low-level box construct, used in OutputForm.
+    </dl>
+
+    """
+
+    attributes = A_HOLD_ALL_COMPLETE | A_PROTECTED | A_READ_PROTECTED
+    summary_text = "box associated to panel"
+
+    def apply_display_form(boxexpr, form, evaluation, expression):
+        """ToExpression[boxexpr_PaneBox, form_]"""
+        return Expression(expression.head, boxexpr.elements[0], form).evaluate(
+            evaluation
+        )
+
+    def apply_display(boxexpr, evaluation):
+        """DisplayForm[boxexpr_PaneBox]"""
+        return boxexpr.elements[0]
+
+
 class RowBox(BoxExpression):
     """
     <url>

mathics/builtin/forms/output.py

@@ -37,6 +37,7 @@
     StringLParen,
     StringRParen,
     eval_baseform,
+    eval_makeboxes_outputform,
     eval_mathmlform,
     eval_tableform,
     eval_texform,
@@ -490,8 +491,13 @@ class OutputForm(FormBaseClass):
      = -Graphics-
     """
 
+    formats = {"OutputForm[s_String]": "s"}
     summary_text = "plain-text output format"
 
+    def eval_makeboxes(self, expr, form, evaluation):
+        """MakeBoxes[OutputForm[expr_], form_]"""
+        return eval_makeboxes_outputform(expr, evaluation, form)
+
 
 class PythonForm(FormBaseClass):
     """

mathics/core/atoms.py

@@ -1016,10 +1016,13 @@ def __str__(self) -> str:
         return '"%s"' % self.value
 
     def atom_to_boxes(self, f, evaluation):
+        return self.make_boxes(f.get_name())
+
+    def make_boxes(self, f):
         from mathics.eval.makeboxes import _boxed_string
 
         inner = str(self.value)
-        if f in SYSTEM_SYMBOLS_INPUT_OR_FULL_FORM:
+        if f in ("System`InputForm", "System`FullForm"):
             inner = '"' + inner.replace("\\", "\\\\") + '"'
             return _boxed_string(inner, **{"System`ShowStringCharacters": SymbolTrue})
         return String('"' + inner + '"')

mathics/eval/makeboxes/__init__.py

@@ -7,6 +7,7 @@
     _boxed_string,
     eval_generic_makeboxes,
     eval_makeboxes,
+    eval_makeboxes_outputform,
     format_element,
     int_to_string_shorter_repr,
     to_boxes,
@@ -18,19 +19,25 @@
     eval_tableform,
     eval_texform,
 )
-from mathics.eval.makeboxes.precedence import builtins_precedence, parenthesize
+from mathics.eval.makeboxes.precedence import (
+    builtins_precedence,
+    compare_precedence,
+    parenthesize,
+)
 
 __all__ = [
     "NumberForm_to_String",
     "StringLParen",
     "StringRParen",
     "_boxed_string",
     "builtins_precedence",
+    "compare_precedence",
     "do_format",
     "eval_baseform",
     "eval_generic_makeboxes",
     "eval_infix",
     "eval_makeboxes",
+    "eval_makeboxes_outputform",
     "eval_mathmlform",
     "eval_postprefix",
     "eval_tableform",

mathics/eval/makeboxes/makeboxes.py

@@ -13,7 +13,7 @@
 from mathics.core.evaluation import Evaluation
 from mathics.core.expression import Expression
 from mathics.core.symbols import Atom, Symbol, SymbolFullForm, SymbolMakeBoxes
-from mathics.core.systemsymbols import SymbolStandardForm
+from mathics.core.systemsymbols import SymbolOutputForm, SymbolStandardForm
 from mathics.eval.makeboxes.formatvalues import do_format
 from mathics.eval.makeboxes.precedence import parenthesize
 
@@ -126,8 +126,21 @@ def int_to_string_shorter_repr(value: int, form: Symbol, max_digits=640):
     return String(value_str)
 
 
+def eval_makeboxes_outputform(expr, evaluation, form):
+    """
+    Build a 2D text representation of the expression.
+    """
+    from mathics.builtin.box.layout import InterpretationBox, PaneBox
+    from mathics.format.outputform import expression_to_outputform_text
+
+    text_outputform = str(expression_to_outputform_text(expr, evaluation, form))
+    elem1 = PaneBox(String(text_outputform))
+    elem2 = Expression(SymbolOutputForm, expr)
+    return InterpretationBox(elem1, elem2)
+
+
 def eval_fullform_makeboxes(
-    self, expr, evaluation: Evaluation, form=SymbolStandardForm
+    expr, evaluation: Evaluation, form=SymbolStandardForm
 ) -> Optional[BaseElement]:
     """
     This function takes the definitions provided by the evaluation
@@ -220,9 +233,27 @@ def format_element(
     Applies formats associated to the expression, and then calls Makeboxes
     """
     evaluation.is_boxing = True
+    while element.get_head() is form:
+        element = element.elements[0]
+
+    if element.has_form("FullForm", 1):
+        return eval_fullform_makeboxes(element.elements[0], evaluation)
+
+    # In order to work like in WMA, `format_element`
+    # should evaluate `MakeBoxes[element//form, StandardForm]`
+    # Then, MakeBoxes[expr_, StandardForm], for any expr,
+    # should apply Format[...] rules, and then
+    # MakeBoxes[...] rules. These rules should be stored
+    # as FormatValues[...]
+    # As a first step in that direction, let's mimic this behaviour
+    # just for the case of OutputForm:
+    if element.has_form("OutputForm", 1):
+        return eval_makeboxes_outputform(element.elements[0], evaluation, form)
+
     expr = do_format(element, evaluation, form)
     if expr is None:
         return None
+
     result = Expression(SymbolMakeBoxes, expr, form)
     result_box = result.evaluate(evaluation)
     if isinstance(result_box, String):

mathics/format/latex.py

@@ -19,6 +19,8 @@
 from mathics.builtin.box.layout import (
     FractionBox,
     GridBox,
+    InterpretationBox,
+    PaneBox,
     RowBox,
     SqrtBox,
     StyleBox,
@@ -133,6 +135,16 @@ def render(format, string, in_text=False):
 add_conversion_fn(String, string)
 
 
+def interpretation_panebox(self, **options):
+    return lookup_conversion_method(self.elements[0], "latex")(
+        self.elements[0], **options
+    )
+
+
+add_conversion_fn(InterpretationBox, interpretation_panebox)
+add_conversion_fn(PaneBox, interpretation_panebox)
+
+
 def fractionbox(self, **options) -> str:
     _options = self.box_options.copy()
     _options.update(options)

mathics/format/mathml.py

@@ -15,6 +15,8 @@
 from mathics.builtin.box.layout import (
     FractionBox,
     GridBox,
+    InterpretationBox,
+    PaneBox,
     RowBox,
     SqrtBox,
     StyleBox,
@@ -110,6 +112,16 @@ def render(format, string):
 add_conversion_fn(String, string)
 
 
+def interpretation_panebox(self, **options):
+    return lookup_conversion_method(self.elements[0], "latex")(
+        self.elements[0], **options
+    )
+
+
+add_conversion_fn(InterpretationBox, interpretation_panebox)
+add_conversion_fn(PaneBox, interpretation_panebox)
+
+
 def fractionbox(self, **options) -> str:
     _options = self.box_options.copy()
     _options.update(options)