Support for PFA in constant expressions

Author: arnaud-lb

Zend/tests/partial_application/constexpr_001.phpt

@@ -0,0 +1,30 @@
+--TEST--
+PFA in constexpr 001
+--FILE--
+<?php
+
+function f($a = g("foo", ?)) {
+    return $a(1);
+}
+
+function g(string $a, int $b) {
+    return [$a, $b];
+}
+
+var_dump(f());
+var_dump(f());
+
+?>
+--EXPECT--
+array(2) {
+  [0]=>
+  string(3) "foo"
+  [1]=>
+  int(1)
+}
+array(2) {
+  [0]=>
+  string(3) "foo"
+  [1]=>
+  int(1)
+}

Zend/tests/partial_application/constexpr_002.phpt

@@ -0,0 +1,22 @@
+--TEST--
+PFA in constexpr: non-constexpr arg
+--FILE--
+<?php
+
+function f($a = g(new stdClass, $x, ?)) {
+    return $a(1);
+}
+
+function g(string $a, int $b) {
+    return [$a, $b];
+}
+
+try {
+    var_dump(f());
+} catch (Error $e) {
+    echo $e::class, ": ", $e->getMessage(), " on line ", $e->getLine();
+}
+
+?>
+--EXPECTF--
+Fatal error: Constant expression contains invalid operations in %s on line %d

Zend/tests/partial_application/constexpr_003.phpt

@@ -0,0 +1,25 @@
+--TEST--
+PFA in constexpr: named args
+--FILE--
+<?php
+
+function f($a = g(c: ?, ...)) {
+    return $a(1.5, b: 3);
+}
+
+function g(string $a = 'hello', int $b = 2, float $c = 0) {
+    return [$a, $b, $c];
+}
+
+var_dump(f());
+
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  string(5) "hello"
+  [1]=>
+  int(3)
+  [2]=>
+  float(1.5)
+}

Zend/tests/partial_application/constexpr_004.phpt

@@ -0,0 +1,28 @@
+--TEST--
+PFA in constexpr: extra named args
+--FILE--
+<?php
+
+function f($a = g(?, foo: 'bar', ...)) {
+    return $a(1, bar: 'baz');
+}
+
+function g(...$args) {
+    return [$args];
+}
+
+var_dump(f());
+
+?>
+--EXPECT--
+array(1) {
+  [0]=>
+  array(3) {
+    [0]=>
+    int(1)
+    ["foo"]=>
+    string(3) "bar"
+    ["bar"]=>
+    string(3) "baz"
+  }
+}

Zend/tests/partial_application/constexpr_005.phpt

@@ -0,0 +1,13 @@
+--TEST--
+PFA in constexpr: variadic placeholder must be after positional params
+--FILE--
+<?php
+
+function f($a = g(..., 1)) {
+}
+
+f();
+
+?>
+--EXPECTF--
+Fatal error: Variadic placeholder must be last in %s on line %d

Zend/tests/partial_application/constexpr_006.phpt

@@ -0,0 +1,13 @@
+--TEST--
+PFA in constexpr: variadic placeholder must be after named params
+--FILE--
+<?php
+
+function f($a = g(..., foo: 1)) {
+}
+
+f();
+
+?>
+--EXPECTF--
+Fatal error: Variadic placeholder must be last in %s on line %d

Zend/tests/partial_application/constexpr_007.phpt

@@ -0,0 +1,13 @@
+--TEST--
+PFA in constexpr: variadic placeholder may only appear once
+--FILE--
+<?php
+
+function f($a = g(..., ...)) {
+}
+
+f();
+
+?>
+--EXPECTF--
+Fatal error: Variadic placeholder may only appear once in %s on line %d

Zend/tests/partial_application/constexpr_008.phpt

@@ -0,0 +1,13 @@
+--TEST--
+PFA in constexpr: variadic placeholder not allowed to be named
+--FILE--
+<?php
+
+function f($a = g(foo: ...)) {
+}
+
+f();
+
+?>
+--EXPECTF--
+Parse error: syntax error, unexpected token "..." in %s on line %d

Zend/tests/partial_application/constexpr_010.phpt

@@ -0,0 +1,20 @@
+--TEST--
+PFA in constexpr: error during partial creation
+--FILE--
+<?php
+
+function f($a = g(?)) {
+}
+
+function g($a, $b) {
+}
+
+try {
+    f();
+} catch (Error $e) {
+    echo $e::class, ": ", $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+ArgumentCountError: Partial application of g() expects exactly 2 arguments, 1 given

Zend/tests/partial_application/constexpr_011.phpt

@@ -0,0 +1,33 @@
+--TEST--
+PFA in constexpr: error during arg list evaluation
+--FILE--
+<?php
+
+function f($a = g(strlen(?), e: strlen(?), a: strlen(?), ...)) {
+}
+
+function g($a, $b, $c, $d, $e) {
+}
+
+function h($a = i(strlen(?), a: strlen(?), b: invalid(?), ...)) {
+}
+
+function i(...$args) {
+}
+
+try {
+    f();
+} catch (Error $e) {
+    echo $e::class, ": ", $e->getMessage(), "\n";
+}
+
+try {
+    h();
+} catch (Error $e) {
+    echo $e::class, ": ", $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+Error: Named parameter $a overwrites previous argument
+Error: Call to undefined function invalid()