feature #19528 [ExpressionLanguage] Mention parsing and linting (alexandre-daubois)

This PR was merged into the 6.4 branch.

Discussion
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[ExpressionLanguage] Mention parsing and linting

Required for #19521

Commits
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42b5153 [ExpressionLanguage] Mention parsing and linting

Author: OskarStark

components/expression_language.rst

@@ -96,6 +96,26 @@ can chain multiple coalescing operators.
 
     The null-coalescing operator was introduced in Symfony 6.2.
 
+Parsing and Linting Expressions
+...............................
+
+The ExpressionLanguage component provides a way to parse and lint expressions.
+The :method:`Symfony\\Component\\ExpressionLanguage\\ExpressionLanguage::parse`
+method returns a :class:`Symfony\\Component\\ExpressionLanguage\\ParsedExpression`
+instance that can be used to inspect and manipulate the expression. The
+:method:`Symfony\\Component\\ExpressionLanguage\\ExpressionLanguage::lint`, on the
+other hand, returns a boolean indicating if the expression is valid or not::
+
+    use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
+
+    $expressionLanguage = new ExpressionLanguage();
+
+    var_dump($expressionLanguage->parse('1 + 2'));
+    // displays the AST nodes of the expression which can be
+    // inspected and manipulated
+
+    var_dump($expressionLanguage->lint('1 + 2')); // displays true
+
 Passing in Variables
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