Merge 'extensions/regexp: Add support for regexp_replace()' from lgualtieri75

Reviewed-by: Preston Thorpe (@PThorpe92)

Closes #986

extensions/regexp/src/lib.rs

@@ -2,7 +2,7 @@ use limbo_ext::{register_extension, scalar, Value, ValueType};
 use regex::Regex;
 
 register_extension! {
-    scalars: { regexp, regexp_like, regexp_substr }
+    scalars: { regexp, regexp_like, regexp_substr, regexp_replace }
 }
 
 #[scalar(name = "regexp")]
@@ -56,3 +56,29 @@ fn regexp_substr(&self, args: &[Value]) -> Value {
         _ => Value::null(),
     }
 }
+
+#[scalar(name = "regexp_replace")]
+fn regexp_replace(&self, args: &[Value]) -> Value {
+    let replacement = match args.get(2) {
+        Some(repl) => repl.to_text().unwrap_or_default(),
+        None => "", // If args[2] does not exist, use an empty string
+    };
+
+    match (args.get(0), args.get(1)) {
+        (Some(haystack), Some(pattern)) => {
+            let Some(haystack_text) = haystack.to_text() else {
+                return Value::from_text("".to_string()); // Return an empty string if haystack is not valid
+            };
+            let Some(pattern_text) = pattern.to_text() else {
+                return Value::from_text("".to_string()); // Return an empty string if pattern is not valid
+            };
+
+            let re = match Regex::new(&pattern_text) {
+                Ok(re) => re,
+                Err(_) => return Value::from_text("".to_string()), // Return an empty string if regex compilation fails
+            };
+            Value::from_text(re.replace(&haystack_text, replacement).to_string())
+        }
+        _ => Value::from_text("".to_string()), // Return an empty string for invalid value types
+    }
+}

testing/extensions.py

@@ -190,6 +190,21 @@ def test_regexp(pipe):
     run_test(
         pipe, "SELECT regexp_substr('the year is unknow', '[0-9]+');", returns_null
     )
+    run_test(
+        pipe,
+        "select regexp_replace('the year is 2021', '[0-9]+', '2050') = 'the year is 2050';",
+        validate_true,
+    )
+    run_test(
+        pipe,
+        "select regexp_replace('the year is 2021', '2k21', '2050') = 'the year is 2021';",
+        validate_true,
+    )
+    run_test(
+        pipe,
+        "select regexp_replace('the year is 2021', '([0-9]+)', '$1 or 2050') = 'the year is 2021 or 2050';",
+        validate_true,
+    )
 
 
 def validate_median(res):