Features: Conditional expression and try...on error block.

- Feature (experimental syntax?): "X if (bool) else Y" conditional expression.
  - Usage should be simpler than writing a full, potentially multilined IF statement.
    ```
    if (bool) {
      result = X;
    } else {
      result = Y;
    }
    ```
    versus the new `result = X if (bool) else Y`.
- Feature (experimental): "try ... on error" construct.
  - It is now possible to catch errors using new "try { .... } on error { ... }" construct.
  - This was handy for writing language tests that are expected to fail.
    - I'm unsure of any other advantages for end-users given the potential scope of Primi. We will see...
  - Handler class: TryStatement.
- Fixed grammar bug:
  - It was not possible to place //comments inside array definition that spans multiple lines. That's possible now.
- Fixed bug in HandlerFactory:
  - $strict flag being true was silently ignored when a handler was missing (the factory returned false) in any previous non-strict calls. This is fixed now.

example/try_error.primi

@@ -0,0 +1,15 @@
+//
+// try..on error block catches any errors.
+//
+
+was_error = false
+executed_after_error = false
+try {
+	// Division by zero, bruh!
+	1 / 0
+	executed_after_error = true
+} on error {
+	was_error = true
+}
+assert(was_error, 'Raised error was caught')
+assert(!executed_after_error, 'Code after error was not executed')

src/Context.php

@@ -70,7 +70,7 @@ public function getVariable(string $name): ?Value {
 			return self::$globals[$name];
 		}
 
-		// This should be slightly faster than throwsin exceptions for undefined
+		// This should be slightly faster than throwing exceptions for undefined
 		// variables.
 		return null;
 

src/factories/HandlerFactory.php

@@ -8,21 +8,20 @@ class HandlerFactory extends \Smuuf\Primi\StrictObject {
 
 	public static function get(string $name, ?bool $strict = true) {
 
-		// Using caching should be faster than repeatedly building strings and checking classes and stuff.
-		if (isset(self::$cache[$name])) {
-			return self::$cache[$name];
+		// Using caching is faster than repeatedly building strings and checking
+		// classes and stuff.
+		$class = self::$cache[$name] ?? (
+			class_exists($class = __NAMESPACE__ . "\\Handlers\\$name")
+				? $class
+				: false
+		);
+
+		if ($class === false && $strict) {
+			throw new \LogicException("Handler '$name' not found.");
 		}
 
-		$className = __NAMESPACE__ . "\\Handlers\\$name";
-		if (!class_exists($className)) {
-			if ($strict) {
-				throw new \LogicException("Handler '$className' not found.");
-			}
-			$className = false;
-		}
-
-		self::$cache[$name] = $className;
-		return $className;
+		self::$cache[$name] = $class;
+		return $class;
 
 	}
 

src/handlers/CondExpr.php

@@ -0,0 +1,46 @@
+<?php
+
+namespace Smuuf\Primi\Handlers;
+
+use \Smuuf\Primi\Context;
+use \Smuuf\Primi\ErrorException;
+use \Smuuf\Primi\HandlerFactory;
+use \Smuuf\Primi\Helpers\Common;
+use \Smuuf\Primi\Helpers\SimpleHandler;
+use \Smuuf\Primi\InternalUndefinedTruthnessException;
+
+class CondExpr extends SimpleHandler {
+
+	public static function handle(array $node, Context $context) {
+
+		// Execute the left-hand node and get its return value.
+		$condHandler = HandlerFactory::get($node['cond']['name']);
+		$return = $condHandler::handle($node['cond'], $context);
+
+		try {
+
+			// If the result of the left hand equals to truthy value,
+			// execute the code branch stored in the right-hand node.
+			if (Common::isTruthy($return)) {
+				$trueHandler = HandlerFactory::get($node['true']['name']);
+				return $trueHandler::handle($node['true'], $context);
+			} else {
+				$falseHandler = HandlerFactory::get($node['false']['name']);
+				return $falseHandler::handle($node['false'], $context);
+			}
+
+		} catch (InternalUndefinedTruthnessException $e) {
+			throw new ErrorException($e->getMessage(), $node);
+		}
+
+	}
+
+	public static function reduce(array &$node): void {
+
+		if (!isset($node['cond'])) {
+			$node = $node['true'];
+		}
+
+	}
+
+}

src/handlers/TryStatement.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Smuuf\Primi\Handlers;
+
+use \Smuuf\Primi\Context;
+use \Smuuf\Primi\ErrorException;
+use \Smuuf\Primi\HandlerFactory;
+use \Smuuf\Primi\Helpers\SimpleHandler;
+
+class TryStatement extends SimpleHandler {
+
+	public static function handle(array $node, Context $context) {
+
+		try {
+
+			// Execute the main code.
+			$mainHandler = HandlerFactory::get($node['main']['name']);
+			return $mainHandler::handle($node['main'], $context);
+
+		} catch (ErrorException $e) {
+
+			// Execute the onerror block if any error occured with the main
+			// code.
+			$errorHandler = HandlerFactory::get($node['onerror']['name']);
+			return $errorHandler::handle($node['onerror'], $context);
+
+		}
+
+	}
+
+}