Add list comprehension

pages/querying/differences-in-cypher-implementations.mdx

@@ -187,13 +187,6 @@ In other cases, Memgraph does not yet support patterns in functions, e.g. `size(
 Most of the time, the same functionalities can be expressed differently in Memgraph
 using `OPTIONAL` expansions, function calls, etc.
 
-{<h4 className="custom-header">List comprehension</h4>}
-The following type of query is not yet supported in Memgraph:
-```cypher
-MATCH (keanu:Person {name:'Keanu Reeves'})
-RETURN [x IN keanu.resume WHERE x contains 'The Matrix'] AS matrixList
-```
-
 ### Unsupported expressions
 
 {<h4 className="custom-header">Cypher expressions</h4>}

pages/querying/expressions.mdx

@@ -192,3 +192,63 @@ WITH keanu,[(keanu)-->(b:Movie) | b.title]  + [(keanu)-->(b:Movie) | b.released]
 SET keanu.resume = movieTitles
 RETURN keanu.resume
 ```
+
+## List comprehension
+
+List comprehension is a syntactic construct in Cypher that allows for the creation of a new list by evaluating an expression over each element of an existing list, optionally filtering elements based on a predicate. This feature is particularly useful for transforming and filtering data within queries.
+
+The general syntax for list comprehension in Cypher is:
+
+```cypher
+[variable IN list [WHERE predicate] | expression]
+```
+
+- **`variable`**: Represents each element in the original list.
+- **`list`**: The original list to iterate over.
+- **`predicate`** (optional): A condition that filters elements; only elements satisfying this condition are processed.
+- **`expression`**: An expression applied to each filtered element; the results form the new list.
+
+**Examples:**
+
+1. **Transforming a List:**
+
+   To create a list of squares from a list of numbers:
+
+   ```cypher
+   RETURN [x IN [1, 2, 3, 4] | x * x] AS squares
+   ```
+
+   **Result:** `[1, 4, 9, 16]`
+
+2. **Filtering a List:**
+
+   To filter out even numbers from a list:
+
+   ```cypher
+   RETURN [x IN [1, 2, 3, 4] WHERE x % 2 <> 0] AS oddNumbers
+   ```
+
+   **Result:** `[1, 3]`
+
+3. **Combining Transformation and Filtering:**
+
+   To create a list of squares of even numbers:
+
+   ```cypher
+   RETURN [x IN [1, 2, 3, 4] WHERE x % 2 = 0 | x * x] AS evenSquares
+   ```
+
+   **Result:** `[4, 16]`
+
+4. **Extracting Node Properties:**
+
+   Assuming a graph where `Person` nodes are connected to `Movie` nodes with an `ACTED_IN` relationship, to retrieve the titles of movies released after the year 2000 that a person named 'Alice' acted in:
+
+   ```cypher
+   MATCH (alice:Person {name: 'Alice'})-[:ACTED_IN]->(movie:Movie)
+   RETURN [m IN collect(movie) WHERE m.released > 2000 | m.title] AS recentMovies
+   ```
+
+   **Result:** A list of movie titles released after 2000 that 'Alice' acted in.
+
+List comprehensions enhance the expressiveness of Cypher queries by enabling concise data transformation and filtering directly within the query syntax.