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Thread-Topic: [RFC] Configurable callback to dump results of expressions in
 `php -a`
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Date: Sun, 20 Dec 2020 22:36:38 +0000
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Subject: [RFC] Configurable callback to dump results of expressions in `php
 -a`
From: tysonandre775@hotmail.com (tyson andre)

Hi internals,=0A=
=0A=
I've created a new RFC https://wiki.php.net/rfc/readline_interactive_shell_=
result_function=0A=
adding a way to configure a callback to be called to dump the value of sing=
le-expression statements from `php -a`=0A=
(and an ini setting that can be disabled to prevent that callback from bein=
g called).=0A=
=0A=
Many REPLs (Read-Eval-Print Loops) for other programming languages that I'm=
 familiar with=0A=
print a (possibly truncated) representation of the result of expressions, b=
ut PHP doesn't.=0A=
It would be useful to allow users to extend the functionality of the defaul=
t interactive php shell (php -a),=0A=
possibly with auto_prepend_file or through use of command wrappers/aliases,=
 or after loading the shell.=0A=
Prior to this RFC, there was no way to extend the interactive php shell in =
this way.=0A=
(I've seen https://github.com/bobthecow/psysh mentioned as an alternative f=
or php -a while investigating this,=0A=
but that's a shell written from scratch, and doesn't have some functionalit=
y from php -a such as tolerance of fatal errors)=0A=
=0A=
Because PHP's interactive shell is written in C, adding new features or bug=
 fixes is inconvenient - it would require a lot=0A=
of time getting familiar with C programming, PHP's internals and memory man=
agement,=0A=
and with PHP's internal C ast representation.=0A=
It would be easier and more accessible to extend PHP's interactive shell th=
rough code written in PHP rather than code written in C.=0A=
=0A=
This was among the proposed enhancements I brought up in https://externals.=
io/message/111073 .=0A=
An earlier version of the implementation was also created months ago -  htt=
ps://github.com/php/php-src/pull/5962=0A=
=0A=
Thanks,=0A=
- Tyson=