Incompatible PHP OpenAPI changes in PhpStorm 2020.3

In PHP 8, the throw expression has been converted to a statement, so that it can now be used in arrow functions and coalescing and ternary expressions.

The following changes were introduced:

• The PSI element com.jetbrains.php.lang.psi.elements.PhpThrow is now deprecated, and the new PSI element com.jetbrains.php.lang.psi.elements.PhpThrowExpression is introduced instead.

• We encourage using PhpThrowExpression, since such expressions can appear in more places.

• PhpThrow PSI layout has changed: it is now a Statement with a single child PhpThrowExpression. The PhpThrow#getArgument delegates to PhpThrowExpression#getArgument for now.

• In PhpStorm 2020.2, the PhpThrow class will be removed and replaced with StatementImpl.

See the YouTrack issue for details.

Previously supported only in argument lists, trailing commas can now be used in parameter lists, as well.

The following changes were introduced:

• The last psi-element of parameter lists can now be PhpTokenTypes.opCOMMA. This might affect getting the last parameter: earlier the last psi-element of ParameterList was always a parameter but now it can also be a comma.

• If you are using PsiElement.getLastChild() to get the last parameter, it is now recommended replacing it with getting a parameter by index via ParameterList.getParameter(int).

See the YouTrack issue for details.

With this PHP 8 change, it is now possible to catch exceptions without capturing them to variables.

The following changes were introduced:

• Catch now might not have a variable inside. The @Nullable annotation for the method Catch.getException() that returns a variable was already available. However, if you are getting a variable from Catch differently, or ignoring the @Nullable annotation, you need to be aware of this case effective since PHP 8.0.

See the YouTrack issue for details.

The new shorthand syntax allows defining class properties by "promoting" the constructor parameters with a visibility keyword (public, protected, or private).

The following changes were introduced:

• com.jetbrains.php.lang.psi.elements.Parameter now can contain one of com.jetbrains.php.lang.lexer.PhpTokenTypes#tsVARIABLE_MODIFIERS as a child element.

See the YouTrack issue for details.

The new nullsafe operator ?-> with full short-circuiting allows applying the null-coalescing behavior to method calls, thus eliminating the need for additional null checks.

The following changes were introduced:

• com.jetbrains.php.lang.psi.elements.MemberReference now has an optional child com.jetbrains.php.lang.lexer.PhpTokenTypes#opQUEST between the class reference and com.jetbrains.php.lang.lexer.PhpTokenTypes#ARROW.

See the YouTrack issue for details.

With named parameters, you can pass arguments to a function based on the parameter name, rather than its position.

The following changes were introduced:

• The layout of com.jetbrains.php.lang.psi.elements.ParameterList for call sites has changed. Earlier, it was a comma-separated list of arguments; now, each argument can have optional previous siblings: com.jetbrains.php.lang.lexer.PhpTokenTypes#IDENTIFIER and com.jetbrains.php.lang.lexer.PhpTokenTypesopCOLON.

See the YouTrack issue for details.

With attributes, you can provide structured, syntactic metadata to declarations of classes, properties, functions, methods, parameters, and constants.

The following changes were introduced:

• New PSI elements PhpAttribute and PhpAttributesList were added.

• Possible attributes' owners (com.jetbrains.php.lang.psi.elements.Function, com.jetbrains.php.lang.psi.elements.Parameter, and so on) can now have zero or more instances of PhpAttributesList as first children. This means that now it is not safe to assume that PhpPsiElement#getFirstChild will return some token. We encourage finding the needed tokens by IElementType manually.

• If a PHPDoc comment of a named element is preceded by PhpAttribute, it will not be a sibling of a named element, but rather a child. We encourage using PhpNamedElement#getDocComment (which is already updated to reflect the changes) instead of finding the PHPDoc comment manually.

• The stub tree structure has changed for some elements. If this causes problems in plugins, consider using higher-level facilities or contact support for additional help.

See the YouTrack issue for details.

New match expressions provide functionality similar to switch, but with safer semantics and the ability to return values.

The following changes were introduced:

• New PSI elements: PhpMatchExpression and PhpMatchArm.

• A list of match arms is obtained via PhpMatchExpression#getMatchArms(). The default match arm is not included in this list and is obtained by calling PhpMatchExpression#getDefaultMatchArm().

• Each PhpMatchArm provides a list of conditions via PhpMatchArm#getConditions(). The method returns an empty list for the default match arm.

• Match arm body expression is obtained by invoking PhpMatchArm#getBodyExpression().

See the YouTrack issue for details.