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[RFC] Add clamp function #19434

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[RFC] Add clamp function #19434

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3168db8
Implement clamp function
kylekatarnls Aug 9, 2025
90ab306
Improve NAN handling
kylekatarnls Aug 10, 2025
a189b2c
Fix object support for frameless clamp function
kylekatarnls Aug 10, 2025
37cbb4a
Update stub hash
kylekatarnls Aug 10, 2025
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6 changes: 6 additions & 0 deletions ext/standard/basic_functions.stub.php
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Original file line number Diff line number Diff line change
Expand Up @@ -1629,6 +1629,12 @@ function min(mixed $value, mixed ...$values): mixed {}
*/
function max(mixed $value, mixed ...$values): mixed {}

/**
* @compile-time-eval
* @frameless-function {"arity": 3}
*/
function clamp(mixed $value, mixed $min, mixed $max): mixed {}

function array_walk(array|object &$array, callable $callback, mixed $arg = UNKNOWN): true {}

function array_walk_recursive(array|object &$array, callable $callback, mixed $arg = UNKNOWN): true {}
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16 changes: 15 additions & 1 deletion ext/standard/basic_functions_arginfo.h
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73 changes: 73 additions & 0 deletions ext/standard/math.c
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Original file line number Diff line number Diff line change
Expand Up @@ -389,6 +389,79 @@ PHP_FUNCTION(round)
}
/* }}} */

/* {{{ Return the given value if in range of min and max */
PHP_FUNCTION(clamp)
{
zval *zvalue, *zmin, *zmax;

ZEND_PARSE_PARAMETERS_START(3, 3)
Z_PARAM_ZVAL(zvalue)
Z_PARAM_ZVAL(zmin)
Z_PARAM_ZVAL(zmax)
ZEND_PARSE_PARAMETERS_END();

if (EXPECTED(Z_TYPE_P(zmin) == IS_DOUBLE) && UNEXPECTED(zend_isnan(Z_DVAL_P(zmin)))) {
zend_argument_value_error(2, "cannot be NAN");
RETURN_THROWS();
}

if (EXPECTED(Z_TYPE_P(zmax) == IS_DOUBLE) && UNEXPECTED(zend_isnan(Z_DVAL_P(zmax)))) {
zend_argument_value_error(3, "cannot be NAN");
RETURN_THROWS();
}

if (zend_compare(zmin, zmax) > 0) {
zend_argument_value_error(2, "must be smaller than or equal to argument #3 ($max)");
RETURN_THROWS();
}

if (zend_compare(zmax, zvalue) == -1) {
RETURN_COPY(zmax);
}

if (zend_compare(zvalue, zmin) == -1) {
RETURN_COPY(zmin);
}

RETURN_COPY(zvalue);
}
/* }}} */

/* {{{ Return the given value if in range of min and max */
ZEND_FRAMELESS_FUNCTION(clamp, 3)
{
zval *zvalue, *zmin, *zmax;
Z_FLF_PARAM_ZVAL(1, zvalue);
Z_FLF_PARAM_ZVAL(2, zmin);
Z_FLF_PARAM_ZVAL(3, zmax);

if (EXPECTED(Z_TYPE_P(zmin) == IS_DOUBLE) && UNEXPECTED(zend_isnan(Z_DVAL_P(zmin)))) {
zend_argument_value_error(2, "cannot be NAN");
RETURN_THROWS();
}

if (EXPECTED(Z_TYPE_P(zmax) == IS_DOUBLE) && UNEXPECTED(zend_isnan(Z_DVAL_P(zmax)))) {
zend_argument_value_error(3, "cannot be NAN");
RETURN_THROWS();
}

if (zend_compare(zmin, zmax) > 0) {
zend_argument_value_error(2, "must be smaller than or equal to argument #3 ($max)");
RETURN_THROWS();
}

if (zend_compare(zmax, zvalue) == -1) {
RETURN_COPY(zmax);
}

if (zend_compare(zvalue, zmin) == -1) {
RETURN_COPY(zmin);
}

RETURN_COPY(zvalue);
}
/* }}} */

/* {{{ Returns the sine of the number in radians */
PHP_FUNCTION(sin)
{
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61 changes: 61 additions & 0 deletions ext/standard/tests/math/clamp.phpt
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Original file line number Diff line number Diff line change
@@ -0,0 +1,61 @@
--TEST--
clamp() tests
--INI--
precision=14
date.timezone = UTC
--FILE--
<?php

var_dump(clamp(2, 1, 3));
var_dump(clamp(0, 1, 3));
var_dump(clamp(6, 1, 3));
var_dump(clamp(2, 1.3, 3.4));
var_dump(clamp(2.5, 1, 3));
var_dump(clamp(2.5, 1.3, 3.4));
var_dump(clamp(0, 1.3, 3.4));
var_dump(clamp(M_PI, -INF, INF));
var_dump(clamp(NAN, 4, 6));
var_dump(clamp("a", "c", "g"));
var_dump(clamp("d", "c", "g"));
echo clamp('2025-08-01', '2025-08-15', '2025-09-15'), "\n";
echo clamp('2025-08-20', '2025-08-15', '2025-09-15'), "\n";
echo clamp(new \DateTimeImmutable('2025-08-01'), new \DateTimeImmutable('2025-08-15'), new \DateTimeImmutable('2025-09-15'))->format('Y-m-d'), "\n";
echo clamp(new \DateTimeImmutable('2025-08-20'), new \DateTimeImmutable('2025-08-15'), new \DateTimeImmutable('2025-09-15'))->format('Y-m-d'), "\n";

try {
var_dump(clamp(4, NAN, 6));
} catch (ValueError $error) {
echo $error->getMessage(), "\n";
}

try {
var_dump(clamp(7, 6, NAN));
} catch (ValueError $error) {
echo $error->getMessage(), "\n";
}

try {
var_dump(clamp(1, 3, 2));
} catch (ValueError $error) {
echo $error->getMessage(), "\n";
}
?>
--EXPECT--
int(2)
int(1)
int(3)
int(2)
float(2.5)
float(2.5)
float(1.3)
float(3.141592653589793)
float(NAN)
string(1) "c"
string(1) "d"
2025-08-15
2025-08-20
2025-08-15
2025-08-20
clamp(): Argument #2 ($min) cannot be NAN
clamp(): Argument #3 ($max) cannot be NAN
clamp(): Argument #2 ($min) must be smaller than or equal to argument #3 ($max)