More honest test

Author: rocky

test/formtest.py

@@ -4,10 +4,12 @@
 This is a minimal example so we can discuss feasiblity.
 """
 from mathics.builtin.forms.base import box
-from mathics.core.atoms import IntegerM1, Integer1, Rational
+from mathics.core.atoms import IntegerM1, Integer1, Integer2, Rational
 from mathics.core.expression import Expression
+from mathics.core.parser import parse, MathicsSingleLineFeeder
 from mathics.core.symbols import SymbolDivide
 from mathics.core.systemsymbols import (
+    SymbolFractionBox,
     SymbolMakeBoxes,
     SymbolPower,
     SymbolSqrt,
@@ -32,20 +34,29 @@
 # It is not intended to be used in a final implementation.
 
 
-def sqrt_boxform_fn(expr):
+def fractionbox_fn(expr):
+    # To be continued...
+    return Expression(SymbolFractionBox, *expr.elements)
+
+
+def sqrtbox_fn(expr):
     return Expression(SymbolSqrt, expr.elements[0])
 
 
-def power_boxform_fn(expr):
+def powerbox_fn(expr):
     new_expr = expr.elements[0]
     if new_expr.elements[-1] == IntegerM1:
         return Expression(SymbolDivide, Integer1, new_expr.elements[0])
-    elif new_expr.elements[-1] == Rational(1, 2):
+    elif new_expr.elements[-1] in (Rational(1, 2), Integer1 * (Integer2**IntegerM1)):
         return Expression(SymbolSqrt, new_expr.elements[0])
     return new_expr
 
 
-boxform_rules = {SymbolSqrt: sqrt_boxform_fn, SymbolPower: power_boxform_fn}
+boxform_rules = {
+    # SymbolTimes: fractionbox_fn,
+    SymbolPower: powerbox_fn,
+    SymbolSqrt: sqrtbox_fn,
+}
 
 
 def apply_formatvalues_rules(expr, evaluation):
@@ -71,16 +82,23 @@ def apply_formatvalues_rules(expr, evaluation):
 # Begin demo code.
 
 for expr_str in (
-    "1 / x",  # Show off "Division" boxing
+    # FIXME;
+    # "1 / x",  # Show off "Division" boxing
     "a ^ b",  # Show off "Power" boxing
-    "Sqrt[a]",  # Show off "Square-root boxing"
+    "Sqrt[a]",  # "Square-root boxing"
+    "a ^ (1/2)",  # "Square-root boxing"
 ):
-    expr = session.evaluate(expr_str)
-    print("Input expression:  ", expr)
+    print("expression:        ", expr_str)
+
+    # Parse, but don't evaluate expression.
+    expr = parse(session.definitions, MathicsSingleLineFeeder(expr_str))
+    print("Parsed expression: ", expr)
 
     # Here is how Mathics currently evaluates MakeBoxes
     boxed_expr = Expression(SymbolMakeBoxes, expr, SymbolStandardForm)
     print("Mathics MakeBoxes: ", boxed_expr)
+
+    # Evaluate to get final printed/rendered form
     print("Eval'd Makeboxes:  ", boxed_expr.evaluate(session.evaluation))
 
     # Here is how Mathics might better box an expression.