Adding Statement::when conditionable

CHANGELOG.md

@@ -7,6 +7,7 @@ All Notable changes to `Csv` will be documented in this file
 ### Added
 
 - `JsonConverter::withPrettyPrint` now accepts an optional `$identSize` parameter as its unique parameter.
+- `Statement::when` to enable conditionable query building.
 
 ### Deprecated
 

src/Statement.php

@@ -292,6 +292,26 @@ public function limit(int $limit): self
         return $clone;
     }
 
+    /**
+     * Apply the callback if the given "condition" is (or resolves to) true.
+     *
+     * @param (callable($this): bool)|bool $condition
+     * @param callable($this): ($this|null) $callback
+     * @param ?callable($this): ($this|null) $default
+     */
+    public function when(callable|bool $condition, callable $callback, ?callable $default = null): self
+    {
+        if (!is_bool($condition)) {
+            $condition = $condition($this);
+        }
+
+        return match (true) {
+            $condition => $callback($this),
+            null !== $default => $default($this),
+            default => $this,
+        } ?? $this;
+    }
+
     /**
      * Executes the prepared Statement on the {@link TabularDataReader} object.
      *
@@ -437,7 +457,6 @@ protected function buildOrderBy(Iterator $iterator): Iterator
             return $cmp ?? 0;
         };
 
-
         $class = new class () extends ArrayIterator {
             public function seek(int $offset): void
             {