Zend: suggest similar names for undefined function/class/method error by jorgsowa · Pull Request #22589 · php/php-src

jorgsowa · 2026-07-04T11:29:29Z

An idea that I came up with during the implementation of case-sensitive PHP. Small DX improvement over the typos and mistakes in function/classes names.

Because this covers the case of an undefined function, it shouldn't decrease the performance of a properly working application.

Adaptive threshold: names under 8 characters must be within edit distance 1 to be suggested; names 8+ characters allow distance 2. This avoids noisy suggestions for short identifiers (a 1-character edit on a 4-letter name is a big relative change) while still catching multi-typo mistakes in longer names.

We can extend it to constants, etc., if the idea is good enough.

TimWolla

Some feedback regarding the implementation.

NickSdot · 2026-08-05T18:49:06Z

+try {
+    test();
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";


Suggested change

echo $e->getMessage(), "\n";

echo $e::class, ': ', $e->getMessage(), "\n";

NickSdot · 2026-08-05T18:57:45Z

I like this.

Added some nit comments. Context is the ongoing effort in #22799.

LamentXU123 · 2026-08-07T18:54:41Z

I am in favor of this. Just mentioning that this doesn't requires a RFC imho. Improving error message is not a BC break. We only need to send emails to internals to make sure not body rejects, which you already done.

However, since we are very close to the soft feature freeze. @php/release-managers-86 Do you think this qualifies as a post- soft-feature-freeze feature?

When a function, method, class, interface or trait cannot be found, append a "(did you mean X?)" hint naming the closest existing match by Levenshtein distance: Call to undefined function strlenn() (did you mean strlen?) Call to undefined method Calculator::addd() (did you mean add?) Class "ArrayObjekt" not found (did you mean ArrayObject?) Names shorter than 3 characters are not matched. The allowed distance is 1, or 2 for names of 8 or more characters. Matching is case-insensitive and the suggestion uses the declared casing. Function suggestions cover direct and dynamic calls, constant expressions and the opcache JIT. For unqualified calls in a namespace, names in the current namespace are tried first, falling back to global names, mirroring function lookup.

jorgsowa requested review from Girgias and dstogov as code owners July 4, 2026 11:29

github-actions Bot added Category: Engine Extension: opcache Extension: spl ABI break labels Jul 4, 2026

TimWolla requested changes Jul 4, 2026

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Comment thread Zend/zend_execute.c Outdated

Comment thread Zend/zend_execute_API.c Outdated

Comment thread Zend/zend_execute.c Outdated

Comment thread Zend/zend_execute.c Outdated

Comment thread Zend/zend_execute.c Outdated

Comment thread Zend/zend_string.c Outdated

jorgsowa force-pushed the feat/levenshtein-suggestions branch from ad14e87 to 3c111b3 Compare August 3, 2026 21:50

jorgsowa changed the title ~~Zend: suggest similar names for undefined function/method/class errors~~ Zend: suggest similar names for undefined function error Aug 3, 2026

jorgsowa changed the title ~~Zend: suggest similar names for undefined function error~~ Zend: suggest similar names for undefined function/class/method error Aug 3, 2026