compat

Overview ¶

Package compat implements PHP language surface that a script expects to be there rather than a library it calls: functions whose behaviour is defined by what the interpreter does, not by what they compute.

It is wired in by importing it, the way a program imports a database/sql driver:

import _ "github.com/titpetric/phpscript/stdlib/compat"

stdlib does that for you (see stdlib/imports.go). A host that wants a different set builds its Runtime without stdlib.

Output buffering ¶

PHP's ob_* family redirects everything echo would emit into a stack of in-memory buffers, and template engines lean on it: rendering to a string is "start a buffer, include the compiled template, take the contents". That is what MiniTPL\Template::get() is built on.

ob_start();
include $compiled;
$html = ob_get_clean();

The buffers are pushed onto the runtime with runner.PushOutput, so the capture covers everything that reaches Runtime.Output: echo, inline HTML, and builtins that emit text of their own, such as die() with a message.

A function that reports "no buffer is active" returns false, as PHP does, rather than an empty string; the two are distinguishable with ===.

Regular expressions ¶

PHP's preg_* family is PCRE; Go's regexp is RE2, which cannot express backreferences or lookaround. regex.go compiles each pattern with whichever engine can express it, so both `\1` and a linear-time guarantee are available where they apply.