Wolfram Language Paclet Repository
Community-contributed installable additions to the Wolfram Language
Wolfram`Parser`
RecCell  |
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▪
The cell wraps a fresh global symbol kept un-evaluated. A target must outlive the function that built the grammar; a -local symbol can be garbage-collected once the builder returns - its only live reference is held inside - which silently breaks the recursion. The global cell never gets collected and resolves regardless of when its parser is set. This mirrors the -per-rule wiring the paclet's own EBNF front end uses.
▪
Allocate one cell per recursive production. Mutually-recursive productions each get their own cell and reference each other through .
Examples
(4)
Basic Examples
(1)
In[1]:=
cell=
[];list=
"["],
["[0-9]+"],
[cell],
[","],
["]";
[cell,list];
[list,"[1,[2,3],[]]"]
 | RecCell |
| ParseBetween |
 | ParseLiteral |
| ParseSepBy |
 | ParseChoice |
| ParseRegex |
| RecRef |
| ParseLiteral |
| ParseLiteral |
 | SetRec |
 | Parse |
Out[1]=
{1,{2,3},{}}
The same grammar handles a flat list - the recursion is simply not exercised:
In[2]:=
| Parse |
Out[2]=
{1,2,3}
Scope
(1)
Properties & Relations
(1)
Possible Issues
(1)
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""