feat!: add FloatValidator and NumericConstraintsTrait

- Add FloatValidator for dedicated floating-point number validation
- Create NumericConstraintsTrait with shared numeric constraints (min, max, multipleOf, positive, negative)
- Enhance IntValidator with numeric constraints via trait
- Add Validator::isFloat() factory method
- Smart multipleOf() implementation for both int and float types
- Eliminate code duplication between numeric validators

BREAKING CHANGE: Renamed NumberValidator to FloatValidator, isNumber() to isFloat()

Author: lemmon

src/Lemmon/FloatValidator.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace Lemmon;
+
+class FloatValidator extends FieldValidator
+{
+    use NumericConstraintsTrait;
+
+    /**
+     * @inheritDoc
+     */
+    protected function coerceValue(mixed $value): mixed
+    {
+        if (is_numeric($value)) {
+            return is_int($value) ? (float) $value : (float) $value;
+        }
+        return $value;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    protected function validateType(mixed $value, string $key): mixed
+    {
+        if (!is_numeric($value)) {
+            throw new ValidationException(['Value must be a float.']);
+        }
+        return (float) $value;
+    }
+}

src/Lemmon/IntValidator.php

@@ -4,6 +4,8 @@
 
 class IntValidator extends FieldValidator
 {
+    use NumericConstraintsTrait;
+
     /**
      * @inheritDoc
      */

src/Lemmon/NumericConstraintsTrait.php

@@ -0,0 +1,90 @@
+<?php
+
+namespace Lemmon;
+
+/**
+ * Trait providing common numeric validation constraints.
+ *
+ * This trait contains validation methods that are shared between
+ * IntValidator and FloatValidator to eliminate code duplication.
+ */
+trait NumericConstraintsTrait
+{
+    /**
+     * Validates that the value is greater than or equal to the minimum.
+     *
+     * @param int|float $min The minimum value.
+     * @param ?string $message Custom error message.
+     * @return static
+     */
+    public function min(int|float $min, ?string $message = null): static
+    {
+        return $this->addValidation(
+            fn ($value, $key = null, $input = null) => $value >= $min,
+            $message ?? "Value must be at least {$min}."
+        );
+    }
+
+    /**
+     * Validates that the value is less than or equal to the maximum.
+     *
+     * @param int|float $max The maximum value.
+     * @param ?string $message Custom error message.
+     * @return static
+     */
+    public function max(int|float $max, ?string $message = null): static
+    {
+        return $this->addValidation(
+            fn ($value, $key = null, $input = null) => $value <= $max,
+            $message ?? "Value must be at most {$max}."
+        );
+    }
+
+    /**
+     * Validates that the value is a multiple of the given divisor.
+     *
+     * @param int|float $divisor The divisor.
+     * @param ?string $message Custom error message.
+     * @return static
+     */
+    public function multipleOf(int|float $divisor, ?string $message = null): static
+    {
+        return $this->addValidation(
+            function ($value, $key = null, $input = null) use ($divisor) {
+                if (is_int($divisor) && is_int($value)) {
+                    return $value % $divisor === 0;
+                }
+                return fmod((float) $value, (float) $divisor) === 0.0;
+            },
+            $message ?? "Value must be a multiple of {$divisor}."
+        );
+    }
+
+    /**
+     * Validates that the value is positive (greater than zero).
+     *
+     * @param ?string $message Custom error message.
+     * @return static
+     */
+    public function positive(?string $message = null): static
+    {
+        return $this->addValidation(
+            fn ($value, $key = null, $input = null) => $value > 0,
+            $message ?? 'Value must be positive.'
+        );
+    }
+
+    /**
+     * Validates that the value is negative (less than zero).
+     *
+     * @param ?string $message Custom error message.
+     * @return static
+     */
+    public function negative(?string $message = null): static
+    {
+        return $this->addValidation(
+            fn ($value, $key = null, $input = null) => $value < 0,
+            $message ?? 'Value must be negative.'
+        );
+    }
+}

src/Lemmon/Validator.php

@@ -65,4 +65,14 @@ public static function isBool(): BoolValidator
     {
         return new BoolValidator();
     }
+
+    /**
+     * Creates a new FloatValidator for floating-point numbers.
+     *
+     * @return FloatValidator
+     */
+    public static function isFloat(): FloatValidator
+    {
+        return new FloatValidator();
+    }
 }