Variable length arithmetic (#25)

Co-authored-by: tpetry <[email protected]>

Author: jaspertey

README.md

@@ -140,12 +140,12 @@ use Tpetry\QueryExpressions\Operator\Arithmetic\{
 };
 use Tpetry\QueryExpressions\Operator\Value\Value;
 
-new Add(string|Expression $value1, string|Expression $value2);
-new Divide(string|Expression $value1, string|Expression $value2);
-new Modulo(string|Expression $value1, string|Expression $value2);
-new Multiply(string|Expression $value1, string|Expression $value2);
+new Add(string|Expression $value1, string|Expression $value2, string|Expression ...$values);
+new Divide(string|Expression $value1, string|Expression $value2, string|Expression ...$values);
+new Modulo(string|Expression $value1, string|Expression $value2, string|Expression ...$values);
+new Multiply(string|Expression $value1, string|Expression $value2, string|Expression ...$values);
 new Power(string|Expression $value1, string|Expression $value2);
-new Subtract(string|Expression $value1, string|Expression $value2);
+new Subtract(string|Expression $value1, string|Expression $value2, string|Expression ...$values);
 
 // UPDATE user_quotas SET credits = credits - 15 WHERE id = 1985
 $quota->update([

src/Operator/Arithmetic/Add.php

@@ -4,9 +4,7 @@
 
 namespace Tpetry\QueryExpressions\Operator\Arithmetic;
 
-use Tpetry\QueryExpressions\Operator\OperatorExpression;
-
-class Add extends OperatorExpression
+class Add extends ArithmeticExpression
 {
     protected function operator(): string
     {

src/Operator/Arithmetic/ArithmeticExpression.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tpetry\QueryExpressions\Operator\Arithmetic;
+
+use Illuminate\Contracts\Database\Query\Expression;
+use Illuminate\Database\Grammar;
+use Tpetry\QueryExpressions\Concerns\StringizeExpression;
+
+/**
+ * @internal
+ */
+abstract class ArithmeticExpression implements Expression
+{
+    use StringizeExpression;
+
+    /** @var string[]|Expression[] */
+    private readonly array $values;
+
+    public function __construct(
+        private readonly string|Expression $value1,
+        private readonly string|Expression $value2,
+        string|Expression ...$values,
+    ) {
+        $this->values = $values;
+    }
+
+    public function getValue(Grammar $grammar): string
+    {
+        $expression = implode(" {$this->operator()} ", $this->expressions($grammar));
+
+        return "({$expression})";
+    }
+
+    /**
+     * @return array<int, float|int|string>
+     */
+    protected function expressions(Grammar $grammar): array
+    {
+        return array_map(
+            fn (string|Expression $value) => $this->stringize($grammar, $value),
+            [$this->value1, $this->value2, ...$this->values],
+        );
+    }
+
+    abstract protected function operator(): string;
+}

src/Operator/Arithmetic/Divide.php

@@ -4,9 +4,7 @@
 
 namespace Tpetry\QueryExpressions\Operator\Arithmetic;
 
-use Tpetry\QueryExpressions\Operator\OperatorExpression;
-
-class Divide extends OperatorExpression
+class Divide extends ArithmeticExpression
 {
     protected function operator(): string
     {

src/Operator/Arithmetic/Modulo.php

@@ -4,9 +4,7 @@
 
 namespace Tpetry\QueryExpressions\Operator\Arithmetic;
 
-use Tpetry\QueryExpressions\Operator\OperatorExpression;
-
-class Modulo extends OperatorExpression
+class Modulo extends ArithmeticExpression
 {
     protected function operator(): string
     {

src/Operator/Arithmetic/Multiply.php

@@ -4,9 +4,7 @@
 
 namespace Tpetry\QueryExpressions\Operator\Arithmetic;
 
-use Tpetry\QueryExpressions\Operator\OperatorExpression;
-
-class Multiply extends OperatorExpression
+class Multiply extends ArithmeticExpression
 {
     protected function operator(): string
     {

src/Operator/Arithmetic/Power.php

@@ -4,30 +4,43 @@
 
 namespace Tpetry\QueryExpressions\Operator\Arithmetic;
 
-use Illuminate\Contracts\Database\Query\Expression;
 use Illuminate\Database\Grammar;
 use Tpetry\QueryExpressions\Concerns\IdentifiesDriver;
 use Tpetry\QueryExpressions\Concerns\StringizeExpression;
 
-class Power implements Expression
+class Power extends ArithmeticExpression
 {
     use IdentifiesDriver;
     use StringizeExpression;
 
-    public function __construct(
-        private readonly string|Expression $value1,
-        private readonly string|Expression $value2,
-    ) {
+    public function getValue(Grammar $grammar): string
+    {
+        return match ($this->identify($grammar)) {
+            'mysql', 'sqlite', 'sqlsrv' => $this->buildPowerFunctionChain($grammar),
+            'pgsql' => parent::getValue($grammar),
+        };
     }
 
-    public function getValue(Grammar $grammar)
+    protected function buildPowerFunctionChain(Grammar $grammar): string
     {
-        $value1 = $this->stringize($grammar, $this->value1);
-        $value2 = $this->stringize($grammar, $this->value2);
+        $expressions = $this->expressions($grammar);
 
-        return match ($this->identify($grammar)) {
-            'mysql', 'sqlite', 'sqlsrv' => "power({$value1}, {$value2})",
-            'pgsql' => "({$value1} ^ {$value2})",
-        };
+        // Build the initial expressions by using the two required parameters of the object.
+        $value0 = array_shift($expressions);
+        $value1 = array_shift($expressions);
+        $expression = "power({$value0}, {$value1})";
+
+        // For each remaining value call the power function again with the last result and the new value.
+        while (count($expressions) > 0) {
+            $value = array_shift($expressions);
+            $expression = "power({$expression}, $value)";
+        }
+
+        return $expression;
+    }
+
+    protected function operator(): string
+    {
+        return '^';
     }
 }

src/Operator/Arithmetic/Subtract.php

@@ -4,9 +4,7 @@
 
 namespace Tpetry\QueryExpressions\Operator\Arithmetic;
 
-use Tpetry\QueryExpressions\Operator\OperatorExpression;
-
-class Subtract extends OperatorExpression
+class Subtract extends ArithmeticExpression
 {
     protected function operator(): string
     {

tests/Operator/Arithmetic/AddTest.php

@@ -44,3 +44,14 @@
     ->toBePgsql('(0 + "val")')
     ->toBeSqlite('(0 + "val")')
     ->toBeSqlsrv('(0 + [val])');
+
+it('can add variadic values')
+    ->expect(new Add(new Expression(0), 'val1', 'val2', new Expression(1)))
+    ->toBeExecutable(function (Blueprint $table) {
+        $table->integer('val1');
+        $table->integer('val2');
+    })
+    ->toBeMysql('(0 + `val1` + `val2` + 1)')
+    ->toBePgsql('(0 + "val1" + "val2" + 1)')
+    ->toBeSqlite('(0 + "val1" + "val2" + 1)')
+    ->toBeSqlsrv('(0 + [val1] + [val2] + 1)');

tests/Operator/Arithmetic/DivideTest.php

@@ -44,3 +44,14 @@
     ->toBePgsql('(0 / "val")')
     ->toBeSqlite('(0 / "val")')
     ->toBeSqlsrv('(0 / [val])');
+
+it('can divide variadic values')
+    ->expect(new Divide(new Expression(0), 'val1', 'val2', new Expression(1)))
+    ->toBeExecutable(function (Blueprint $table) {
+        $table->integer('val1');
+        $table->integer('val2');
+    })
+    ->toBeMysql('(0 / `val1` / `val2` / 1)')
+    ->toBePgsql('(0 / "val1" / "val2" / 1)')
+    ->toBeSqlite('(0 / "val1" / "val2" / 1)')
+    ->toBeSqlsrv('(0 / [val1] / [val2] / 1)');