WIP: Refactor Keywords implementation

.gitattributes

@@ -1,6 +1,7 @@
 * text=auto
 
 **/*Test.php export-ignore
+**/*TestCase.php export-ignore
 **/Fake*.php export-ignore
 /.gitattributes export-ignore
 /.gitignore export-ignore

.styleci.yml

@@ -1,12 +1,5 @@
-preset: recommended
-
+preset: psr12
 enabled:
   - not_operator_with_successor_space
   - phpdoc_no_empty_return
   - unalign_double_arrow
-
-disabled:
-  - align_double_arrow
-  - phpdoc_align
-  - phpdoc_separation
-  - simplified_null_return

composer.json

@@ -12,7 +12,8 @@
         "php": "^7.4"
     },
     "require-dev": {
-        "phpunit/phpunit": "^8"
+        "phpunit/phpunit": "^8",
+        "sempro/phpunit-pretty-print": "^1.2"
     },
     "autoload": {
         "psr-4": {

phpunit.xml

@@ -1,5 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit bootstrap="vendor/autoload.php" colors="true">
+<phpunit
+    bootstrap="vendor/autoload.php"
+    colors="true"
+    printerClass="Sempro\PHPUnitPrettyPrinter\PrettyPrinter"
+>
     <testsuites>
         <testsuite name="Distil">
             <directory suffix="Test.php">src/</directory>

src/CriteriaTest.php

@@ -6,7 +6,6 @@
 
 use Distil\Exceptions\CannotAddCriterion;
 use Distil\Exceptions\CannotGetCriterion;
-use Distil\FakeCriterion;
 use PHPUnit\Framework\TestCase;
 
 use function array_values;

src/Exceptions/InvalidKeyword.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Distil\Exceptions;
+
+use Distil\Values\BooleanKeyword;
+use RuntimeException;
+
+use function array_keys;
+use function implode;
+
+final class InvalidKeyword extends RuntimeException
+{
+    public static function cannotBeCastedToBoolean(string $keyword): self
+    {
+        return new self(
+            "[$keyword] is not a valid boolean keyword. Valid keywords are: " .
+            implode(', ', array_keys(BooleanKeyword::CASTED_VALUES))
+        );
+    }
+
+    public static function cannotBeCastedToInteger(string $keyword): self
+    {
+        return new self(
+            "[$keyword] is not a valid integer keyword. It must be an string representation of an integer."
+        );
+    }
+
+    public static function cannotBeCastedToDateTime(string $keyword): self
+    {
+        return new self(
+            "[$keyword] is not a valid DateTime keyword. It must be a date/time string " .
+            '(see https://www.php.net/manual/en/datetime.formats.php).'
+        );
+    }
+}

src/FakeCriterion.php

@@ -4,6 +4,9 @@
 
 namespace Distil;
 
+/**
+ * @internal
+ */
 final class FakeCriterion implements Criterion
 {
     use ActsAsCriteriaFactory;

src/Types/BooleanCriterion.php

@@ -4,14 +4,13 @@
 
 use Distil\ActsAsCriteriaFactory;
 use Distil\Criterion;
-use Distil\Exceptions\InvalidCriterionValue;
-use Distil\Keywords\HasKeywords;
-use Distil\Keywords\Keyword;
-use Distil\Keywords\Value;
+use Distil\Values\BooleanKeyword;
+use Distil\Values\ConstructsFromKeyword;
 
-abstract class BooleanCriterion implements Criterion, HasKeywords
+abstract class BooleanCriterion implements Criterion
 {
     use ActsAsCriteriaFactory;
+    use ConstructsFromKeyword;
 
     public const KEYWORD_TRUE = 'true';
     public const KEYWORD_FALSE = 'false';
@@ -28,13 +27,7 @@ public function __construct(bool $value)
      */
     public static function fromString(string $value): self
     {
-        $value = (new Keyword(static::class, $value))->value();
-
-        if (! is_bool($value)) {
-            throw InvalidCriterionValue::expectedBoolean(static::class);
-        }
-
-        return new static($value);
+        return self::fromKeyword(new BooleanKeyword($value));
     }
 
     public function value(): bool
@@ -49,19 +42,6 @@ public function isTruthy(): bool
 
     public function isFalsy(): bool
     {
-        return ! $this->isTruthy();
-    }
-
-    public static function keywords(): array
-    {
-        return [
-            static::KEYWORD_TRUE => true,
-            static::KEYWORD_FALSE => false,
-        ];
-    }
-
-    public function __toString(): string
-    {
-        return (new Value($this, $this->value))->keyword();
+        return ! $this->value;
     }
 }

src/Types/DateTimeCriterion.php

@@ -2,42 +2,41 @@
 
 namespace Distil\Types;
 
-use DateTime;
-use DateTimeImmutable;
 use DateTimeInterface;
 use Distil\ActsAsCriteriaFactory;
 use Distil\Criterion;
-use Distil\Exceptions\InvalidCriterionValue;
-use Distil\Keywords\Keyword;
-use Distil\Keywords\Value;
+use Distil\Values\ConstructsFromKeyword;
+use Distil\Values\DateTimeKeyword;
 
 abstract class DateTimeCriterion implements Criterion
 {
     use ActsAsCriteriaFactory;
+    use ConstructsFromKeyword;
 
     private DateTimeInterface $value;
     private string $format;
 
-    public function __construct(DateTimeInterface $value, string $format = DateTime::ATOM)
+    public function __construct(DateTimeInterface $value, string $format = DateTimeInterface::ATOM)
     {
         $this->value = $value;
         $this->format = $format;
     }
 
+    public function __toString(): string
+    {
+        if ($this->keyword) {
+            return (string) $this->keyword;
+        }
+
+        return $this->value->format($this->format);
+    }
+
     /**
      * @return static
      */
-    public static function fromString(string $value, string $format = DateTime::ATOM): self
+    public static function fromString(string $value): self
     {
-        $value = (new Keyword(static::class, $value))->value();
-
-        if ($value instanceof DateTimeInterface) {
-            return new static($value, $format);
-        } elseif (strtotime($value)) {
-            return new static(new DateTimeImmutable($value), $format);
-        }
-
-        throw InvalidCriterionValue::expectedTimeString(static::class);
+        return self::fromKeyword(new DateTimeKeyword($value));
     }
 
     public function value(): DateTimeInterface
@@ -49,9 +48,4 @@ public function format(): string
     {
         return $this->format;
     }
-
-    public function __toString(): string
-    {
-        return (new Value($this, $this->value))->keyword() ?: $this->value->format($this->format);
-    }
 }

src/Types/IntegerCriterion.php

@@ -5,12 +5,14 @@
 use Distil\ActsAsCriteriaFactory;
 use Distil\Criterion;
 use Distil\Exceptions\InvalidCriterionValue;
-use Distil\Keywords\Keyword;
-use Distil\Keywords\Value;
+use Distil\Values\ConstructsFromKeyword;
+
+use function is_numeric;
 
 abstract class IntegerCriterion implements Criterion
 {
     use ActsAsCriteriaFactory;
+    use ConstructsFromKeyword;
 
     private int $value;
 
@@ -19,13 +21,8 @@ public function __construct(int $value)
         $this->value = $value;
     }
 
-    /**
-     * @return static
-     */
     public static function fromString(string $value): self
     {
-        $value = (new Keyword(static::class, $value))->value();
-
         if (! is_numeric($value)) {
             throw InvalidCriterionValue::expectedNumeric(static::class);
         }
@@ -37,9 +34,4 @@ public function value(): int
     {
         return $this->value;
     }
-
-    public function __toString(): string
-    {
-        return (new Value($this, $this->value))->keyword() ?: (string) $this->value;
-    }
 }

src/Types/StringCriterion.php

@@ -4,27 +4,10 @@
 
 use Distil\ActsAsCriteriaFactory;
 use Distil\Criterion;
-use Distil\Keywords\Keyword;
-use Distil\Keywords\Value;
+use Distil\Values\ConstructsFromKeyword;
 
 abstract class StringCriterion implements Criterion
 {
     use ActsAsCriteriaFactory;
-
-    private string $value;
-
-    public function __construct(string $value)
-    {
-        $this->value = (new Keyword(static::class, $value))->value();
-    }
-
-    public function value(): string
-    {
-        return $this->value;
-    }
-
-    public function __toString(): string
-    {
-        return (new Value($this, $this->value))->keyword() ?: $this->value;
-    }
+    use ConstructsFromKeyword;
 }

src/Values/BooleanKeyword.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Distil\Values;
+
+use Distil\Exceptions\InvalidKeyword;
+
+use function array_key_exists;
+
+final class BooleanKeyword implements Keyword
+{
+    use ConstructsNullableKeyword;
+
+    public const CASTED_VALUES = [
+        'true' => true,
+        '1' => true,
+        'false' => false,
+        '0' => false,
+    ];
+
+    private string $stringValue;
+    private bool $castedValue;
+
+    public function __construct(string $keyword)
+    {
+        $this->guardAgainstInvalidValues($keyword);
+
+        $this->stringValue = $keyword;
+        $this->castedValue = self::CASTED_VALUES[$keyword];
+    }
+
+    private function guardAgainstInvalidValues(string $keyword): void
+    {
+        if ($this->isNotAKeyword($keyword)) {
+            throw InvalidKeyword::cannotBeCastedToBoolean($keyword);
+        }
+    }
+
+    public function __toString(): string
+    {
+        return $this->stringValue;
+    }
+
+    public function castedValue(): bool
+    {
+        return $this->castedValue;
+    }
+
+    private function isNotAKeyword(string $keyword): bool
+    {
+        return ! array_key_exists($keyword, self::CASTED_VALUES);
+    }
+}