filter: Filter JSON-formatted AST.
Description
Apply a filter on the JSON-formatted abstract syntax tree (AST).
Usage
filter(FUN, ..., input = stdin(), output = stdout())
Arguments
- FUN
- the function to be applied on the AST. 
- ...
- optional arguments to - FUN.
 
- input
- a connection object or a character string from which the JSON-formatted AST is read. 
- output
- a connection object or a character string to which the JSON-formatted AST is written.