Add strpos function as a synonym for position

src/expr/src/scalar/func.rs

@@ -2599,7 +2599,7 @@ where
     }
 }
 
-#[sqlfunc(propagates_nulls = true)]
+#[sqlfunc]
 fn position(substring: &str, string: &str) -> Result<i32, EvalError> {
     let char_index = string.find(substring);
 
@@ -2617,6 +2617,11 @@ fn position(substring: &str, string: &str) -> Result<i32, EvalError> {
     }
 }
 
+#[sqlfunc]
+fn strpos(string: &str, substring: &str) -> Result<i32, EvalError> {
+    position(substring, string)
+}
+
 #[sqlfunc(
     propagates_nulls = true,
     // `left` is unfortunately not monotonic (at least for negative second arguments),

src/expr/src/scalar/func/binary.rs

@@ -337,6 +337,7 @@ mod derive {
         ConvertFrom(ConvertFrom),
         Left(Left),
         Position(Position),
+        Strpos(Strpos),
         Right(Right),
         RepeatString(RepeatString),
         Normalize(Normalize),

src/expr/src/scalar/snapshots/mz_expr__scalar__func__position.snap

@@ -1,6 +1,6 @@
 ---
 source: src/expr/src/scalar/func.rs
-expression: "#[sqlfunc(propagates_nulls = true)]\nfn position(substring: &str, string: &str) -> Result<i32, EvalError> {\n    let char_index = string.find(substring);\n    if let Some(char_index) = char_index {\n        let string_prefix = &string[0..char_index];\n        let num_prefix_chars = string_prefix.chars().count();\n        let num_prefix_chars = i32::try_from(num_prefix_chars)\n            .map_err(|_| EvalError::Int32OutOfRange(\n                num_prefix_chars.to_string().into(),\n            ))?;\n        Ok(num_prefix_chars + 1)\n    } else {\n        Ok(0)\n    }\n}\n"
+expression: "#[sqlfunc()]\nfn position(substring: &str, string: &str) -> Result<i32, EvalError> {\n    let char_index = string.find(substring);\n    if let Some(char_index) = char_index {\n        let string_prefix = &string[0..char_index];\n        let num_prefix_chars = string_prefix.chars().count();\n        let num_prefix_chars = i32::try_from(num_prefix_chars)\n            .map_err(|_| EvalError::Int32OutOfRange(\n                num_prefix_chars.to_string().into(),\n            ))?;\n        Ok(num_prefix_chars + 1)\n    } else {\n        Ok(0)\n    }\n}\n"
 ---
 #[derive(
     proptest_derive::Arbitrary,
@@ -46,9 +46,6 @@ impl<'a> crate::func::binary::EagerBinaryFunc<'a> for Position {
                         && (input_type_a.nullable || input_type_b.nullable)),
             )
     }
-    fn propagates_nulls(&self) -> bool {
-        true
-    }
 }
 impl std::fmt::Display for Position {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {

src/expr/src/scalar/snapshots/mz_expr__scalar__func__strpos.snap

@@ -0,0 +1,57 @@
+---
+source: src/expr/src/scalar/func.rs
+expression: "#[sqlfunc()]\nfn strpos(string: &str, substring: &str) -> Result<i32, EvalError> {\n    position(substring, string)\n}\n"
+---
+#[derive(
+    proptest_derive::Arbitrary,
+    Ord,
+    PartialOrd,
+    Clone,
+    Debug,
+    Eq,
+    PartialEq,
+    serde::Serialize,
+    serde::Deserialize,
+    Hash,
+    mz_lowertest::MzReflect
+)]
+pub struct Strpos;
+impl<'a> crate::func::binary::EagerBinaryFunc<'a> for Strpos {
+    type Input1 = &'a str;
+    type Input2 = &'a str;
+    type Output = Result<i32, EvalError>;
+    fn call(
+        &self,
+        a: Self::Input1,
+        b: Self::Input2,
+        temp_storage: &'a mz_repr::RowArena,
+    ) -> Self::Output {
+        strpos(a, b)
+    }
+    fn output_type(
+        &self,
+        input_type_a: mz_repr::SqlColumnType,
+        input_type_b: mz_repr::SqlColumnType,
+    ) -> mz_repr::SqlColumnType {
+        use mz_repr::AsColumnType;
+        let output = Self::Output::as_column_type();
+        let propagates_nulls = crate::func::binary::EagerBinaryFunc::propagates_nulls(
+            self,
+        );
+        let nullable = output.nullable;
+        output
+            .nullable(
+                nullable
+                    || (propagates_nulls
+                        && (input_type_a.nullable || input_type_b.nullable)),
+            )
+    }
+}
+impl std::fmt::Display for Strpos {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        f.write_str(stringify!(strpos))
+    }
+}
+fn strpos(string: &str, substring: &str) -> Result<i32, EvalError> {
+    position(substring, string)
+}

src/sql/src/func.rs

@@ -2622,6 +2622,9 @@ pub static PG_CATALOG_BUILTINS: LazyLock<BTreeMap<&'static str, Func>> = LazyLoc
         "asinh" => Scalar {
             params!(Float64) => UnaryFunc::Asinh(func::Asinh) => Float64, 2465;
         },
+        "strpos" => Scalar {
+            params!(String, String) => BinaryFunc::from(func::Strpos) => Int32, 868;
+        },
         "split_part" => Scalar {
             params!(String, String, Int32) => VariadicFunc::SplitPart => String, 2088;
         },