"HeldExpression" (interpreter type)

Wolfram Language expression.

DetailsDetails

Allowed FormsAllowed Forms

  • Any valid Wolfram Language expression.

Restriction SpecificationsRestriction Specifications

InterpretationInterpretation

ExamplesExamplesopen allclose all

Basic Examples  (5)Basic Examples  (5)

Interpret expressions and avoid evaluation:

In[1]:=
Click for copyable input
Out[1]=
In[2]:=
Click for copyable input
Out[2]=

No evaluation is attempted when matching the choices:

In[1]:=
Click for copyable input
Out[1]=
In[2]:=
Click for copyable input
Out[2]=

By default, only expressions with no side effect are allowed:

In[1]:=
Click for copyable input
Out[1]=

This can be changed by allowing All symbols:

In[2]:=
Click for copyable input
Out[2]=

Restrict to a list of symbols:

In[1]:=
Click for copyable input
Out[1]=
In[2]:=
Click for copyable input
Out[2]=

Specify contexts for the allowed and output symbols:

In[1]:=
Click for copyable input
Out[1]=