feature: add ilike support (#78)

add ilike support

Co-authored-by: jianjian.xie <jianjian.xie@uber.com>

Author: jja725

rust/lance-graph/src/ast.rs

@@ -218,11 +218,16 @@ pub enum BooleanExpression {
         expression: ValueExpression,
         list: Vec<ValueExpression>,
     },
-    /// LIKE pattern matching
+    /// LIKE pattern matching (case-sensitive)
     Like {
         expression: ValueExpression,
         pattern: String,
     },
+    /// ILIKE pattern matching (case-insensitive)
+    ILike {
+        expression: ValueExpression,
+        pattern: String,
+    },
     /// CONTAINS substring matching
     Contains {
         expression: ValueExpression,

rust/lance-graph/src/datafusion_planner/expression.rs

@@ -75,6 +75,10 @@ pub(crate) fn to_df_boolean_expr(expr: &BooleanExpression) -> Expr {
             expression,
             pattern,
         } => create_like_expr(expression, pattern, false),
+        BE::ILike {
+            expression,
+            pattern,
+        } => create_like_expr(expression, pattern, true),
         BE::Contains {
             expression,
             substring,
@@ -476,6 +480,85 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_boolean_expr_ilike() {
+        let expr = BooleanExpression::ILike {
+            expression: ValueExpression::Property(PropertyRef {
+                variable: "p".into(),
+                property: "name".into(),
+            }),
+            pattern: "alice%".into(),
+        };
+
+        if let Expr::Like(like_expr) = to_df_boolean_expr(&expr) {
+            assert!(!like_expr.negated, "Should not be negated");
+            assert!(
+                like_expr.case_insensitive,
+                "ILIKE should be case insensitive"
+            );
+            assert_eq!(like_expr.escape_char, None, "Should have no escape char");
+            match *like_expr.expr {
+                Expr::Column(ref col_expr) => {
+                    assert_eq!(col_expr.name(), "p__name");
+                }
+                other => panic!("Expected column expression, got {:?}", other),
+            }
+            // Check pattern is a literal
+            match *like_expr.pattern {
+                Expr::Literal(ref scalar, _) => {
+                    let s = format!("{:?}", scalar);
+                    assert!(
+                        s.contains("alice%"),
+                        "Pattern should be 'alice%', got: {}",
+                        s
+                    );
+                }
+                other => panic!("Expected literal pattern, got {:?}", other),
+            }
+        } else {
+            panic!("Expected Like expression");
+        }
+    }
+
+    #[test]
+    fn test_boolean_expr_like_vs_ilike_case_sensitivity() {
+        // Test LIKE (case-sensitive)
+        let like_expr = BooleanExpression::Like {
+            expression: ValueExpression::Property(PropertyRef {
+                variable: "p".into(),
+                property: "name".into(),
+            }),
+            pattern: "Test%".into(),
+        };
+
+        if let Expr::Like(like) = to_df_boolean_expr(&like_expr) {
+            assert!(
+                !like.case_insensitive,
+                "LIKE should be case-sensitive (case_insensitive = false)"
+            );
+        } else {
+            panic!("Expected Like expression");
+        }
+
+        // Test ILIKE (case-insensitive)
+        let ilike_expr = BooleanExpression::ILike {
+            expression: ValueExpression::Property(PropertyRef {
+                variable: "p".into(),
+                property: "name".into(),
+            }),
+            pattern: "Test%".into(),
+        };
+
+        if let Expr::Like(ilike) = to_df_boolean_expr(&ilike_expr) {
+            assert!(
+                ilike.case_insensitive,
+                "ILIKE should be case-insensitive (case_insensitive = true)"
+            );
+        } else {
+            panic!("Expected Like expression");
+        }
+    }
+
     #[test]
     fn test_boolean_expr_like_with_wildcard() {
         let expr = BooleanExpression::Like {

rust/lance-graph/src/parser.rs

@@ -341,6 +341,18 @@ fn comparison_expression(input: &str) -> IResult<&str, BooleanExpression> {
             },
         ));
     }
+    // Match ILIKE pattern (case-insensitive LIKE)
+    if let Ok((input_after_ilike, (_, _, pattern))) =
+        tuple((tag_no_case("ILIKE"), multispace0, string_literal))(input)
+    {
+        return Ok((
+            input_after_ilike,
+            BooleanExpression::ILike {
+                expression: left,
+                pattern,
+            },
+        ));
+    }
     // Match CONTAINS substring
     if let Ok((input_after_contains, (_, _, substring))) =
         tuple((tag_no_case("CONTAINS"), multispace0, string_literal))(input)
@@ -1265,4 +1277,62 @@ mod tests {
             _ => panic!("Expected AND expression"),
         }
     }
+
+    #[test]
+    fn test_parse_ilike_pattern() {
+        let query = "MATCH (n:Person) WHERE n.name ILIKE 'alice%' RETURN n.name";
+        let result = parse_cypher_query(query);
+        assert!(result.is_ok(), "ILIKE pattern should parse successfully");
+
+        let ast = result.unwrap();
+        let where_clause = ast.where_clause.expect("Expected WHERE clause");
+
+        match where_clause.expression {
+            BooleanExpression::ILike {
+                expression,
+                pattern,
+            } => {
+                match expression {
+                    ValueExpression::Property(prop) => {
+                        assert_eq!(prop.variable, "n");
+                        assert_eq!(prop.property, "name");
+                    }
+                    _ => panic!("Expected property expression"),
+                }
+                assert_eq!(pattern, "alice%");
+            }
+            _ => panic!("Expected ILIKE expression"),
+        }
+    }
+
+    #[test]
+    fn test_parse_like_and_ilike_together() {
+        let query =
+            "MATCH (n:Person) WHERE n.name LIKE 'Alice%' OR n.name ILIKE 'bob%' RETURN n.name";
+        let result = parse_cypher_query(query);
+        assert!(result.is_ok(), "LIKE and ILIKE together should parse");
+
+        let ast = result.unwrap();
+        let where_clause = ast.where_clause.expect("Expected WHERE clause");
+
+        match where_clause.expression {
+            BooleanExpression::Or(left, right) => {
+                // Left should be LIKE (case-sensitive)
+                match *left {
+                    BooleanExpression::Like { pattern, .. } => {
+                        assert_eq!(pattern, "Alice%");
+                    }
+                    _ => panic!("Expected LIKE expression on left"),
+                }
+                // Right should be ILIKE (case-insensitive)
+                match *right {
+                    BooleanExpression::ILike { pattern, .. } => {
+                        assert_eq!(pattern, "bob%");
+                    }
+                    _ => panic!("Expected ILIKE expression on right"),
+                }
+            }
+            _ => panic!("Expected OR expression"),
+        }
+    }
 }

rust/lance-graph/src/semantic.rs

@@ -247,6 +247,9 @@ impl SemanticAnalyzer {
             BooleanExpression::Like { expression, .. } => {
                 self.analyze_value_expression(expression)?;
             }
+            BooleanExpression::ILike { expression, .. } => {
+                self.analyze_value_expression(expression)?;
+            }
             BooleanExpression::Contains { expression, .. } => {
                 self.analyze_value_expression(expression)?;
             }