> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/perl6-rosettacode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/m/mad_libs.md).

# Mad Libs

Some explanation: `S:g[...] = ...` is a global substitution that returns its result. `%` is an anonymous state variable in which we cache any results of a prompt using the `//=` operator, which assigns only if the left side is undefined. `slurp` reads an entire file from STDIN or as named in the argument list.

```perl
print S:g[ '<' (.*?) '>' ] = %.{$0} //= prompt "$0? " given slurp;
```

Sample run:

```
$ madlibs walk
name? Phydeaux
He or She? She
noun? flea
Phydeaux went for a walk in the park. She
found a flea. Phydeaux decided to take it home.
```