Function Repository Resource:

RecursiveRewrite

Source Notebook

Rewrite an expression, replacing repeatedly by strings

Contributed by: Enrique Zeleny

ResourceFunction["RecursiveRewrite"][expr]

rewrites expr, replacing repeatedly by strings.

Details and Options

Any string can be used in the "RewriteSymbol" option.

Examples

Basic Examples (4)

Choose an expression:

In[1]:=

Get a list of replacements to rewrite the expression:

In[2]:=

Out[2]=

In[3]:=

Out[3]=

Recover the original expression, applying replacements only six times, starting with the final string:

In[4]:=

Out[4]=

To see the values of subexpressions, you can use the function FromRecursiveRewrite instead:

In[5]:=

Out[5]=

Scope (1)

RecursiveRewrite prevents evaluation as it rewrites:

In[6]:=

$ResourceFunction["RecursiveRewrite"][ Hold[{Quantity[x, "Dollars"], Print[1 + 1], Hold@Image[Plot[Sin[x], {x, 0, 2 \[Pi]}, ImageSize -> 200]]}]]$

Out[6]=

In[7]:=

Out[7]=

Options (4)

RewriteSymbol (4)

Start with an expression:

In[8]:=

Rewrite a subexpression using the symbol "R":

In[9]:=

Out[9]=

Recover the subexpression:

In[10]:=

Out[10]=

Rewrite the expression inside the square root for only six steps and write the strings as subscripts:

In[11]:=

Out[11]=

Possible Issues (1)

Avoid using strings identical to rewrite symbols:

In[12]:=

Out[12]=

In[13]:=

Out[13]=

Requirements

Wolfram Language 11.3 (March 2018) or above

Version History

1.0.1 – 19 October 2020
1.0.0 – 06 March 2019

License Information

This work is licensed under a Creative Commons Attribution 4.0 International License