[FLINK-37924][table] Update expected argument types and signatures for Variant access

Author: JinkunLiu

flink-table/flink-table-common/src/main/java/org/apache/flink/table/types/inference/strategies/ItemAtIndexArgumentTypeStrategy.java

@@ -120,6 +120,6 @@ public Optional<DataType> inferArgumentType(
     public Signature.Argument getExpectedArgument(
             FunctionDefinition functionDefinition, int argumentPos) {
         return Signature.Argument.of(
-                "[<INTEGER NUMERIC> | <MAP_KEY_TYPE> | <CHARACTER STRING> or <INTEGER NUMERIC>]");
+                "[<CHARACTER STRING> | <INTEGER NUMERIC> | <MAP_KEY_TYPE>]");
     }
 }

flink-table/flink-table-common/src/test/java/org/apache/flink/table/types/inference/ItemAtIndexArgumentTypeStrategyTest.java

@@ -42,7 +42,7 @@ protected Stream<TestSpec> testData() {
                                 DataTypes.ARRAY(DataTypes.STRING().notNull()),
                                 DataTypes.SMALLINT().notNull())
                         .expectSignature(
-                                "f([<ARRAY> | <MAP> | <VARIANT>], [<INTEGER NUMERIC> | <MAP_KEY_TYPE> | <CHARACTER STRING> or <INTEGER NUMERIC>])")
+                                "f([<ARRAY> | <MAP> | <VARIANT>], [<CHARACTER STRING> | <INTEGER NUMERIC> | <MAP_KEY_TYPE>])")
                         .expectArgumentTypes(
                                 DataTypes.ARRAY(DataTypes.STRING().notNull()),
                                 DataTypes.SMALLINT().notNull()),
@@ -58,7 +58,7 @@ protected Stream<TestSpec> testData() {
                                 DataTypes.MAP(DataTypes.BIGINT(), DataTypes.STRING().notNull()),
                                 DataTypes.SMALLINT())
                         .expectSignature(
-                                "f([<ARRAY> | <MAP> | <VARIANT>], [<INTEGER NUMERIC> | <MAP_KEY_TYPE> | <CHARACTER STRING> or <INTEGER NUMERIC>])")
+                                "f([<ARRAY> | <MAP> | <VARIANT>], [<CHARACTER STRING> | <INTEGER NUMERIC> | <MAP_KEY_TYPE>])")
                         .expectArgumentTypes(
                                 DataTypes.MAP(DataTypes.BIGINT(), DataTypes.STRING().notNull()),
                                 DataTypes.BIGINT()),
@@ -78,7 +78,7 @@ protected Stream<TestSpec> testData() {
                         .calledWithArgumentTypes(
                                 DataTypes.VARIANT(), DataTypes.SMALLINT().notNull())
                         .expectSignature(
-                                "f([<ARRAY> | <MAP> | <VARIANT>], [<INTEGER NUMERIC> | <MAP_KEY_TYPE> | <CHARACTER STRING> or <INTEGER NUMERIC>])")
+                                "f([<ARRAY> | <MAP> | <VARIANT>], [<CHARACTER STRING> | <INTEGER NUMERIC> | <MAP_KEY_TYPE>])")
                         .expectArgumentTypes(DataTypes.VARIANT(), DataTypes.SMALLINT().notNull()),
                 TestSpec.forStrategy(
                                 "Validate incorrect index for a variant", ITEM_AT_INPUT_STRATEGY)
@@ -90,7 +90,7 @@ protected Stream<TestSpec> testData() {
                 TestSpec.forStrategy("Validate string key for a variant", ITEM_AT_INPUT_STRATEGY)
                         .calledWithArgumentTypes(DataTypes.VARIANT(), DataTypes.STRING().notNull())
                         .expectSignature(
-                                "f([<ARRAY> | <MAP> | <VARIANT>], [<INTEGER NUMERIC> | <MAP_KEY_TYPE> | <CHARACTER STRING> or <INTEGER NUMERIC>])")
+                                "f([<ARRAY> | <MAP> | <VARIANT>], [<CHARACTER STRING> | <INTEGER NUMERIC> | <MAP_KEY_TYPE>])")
                         .expectArgumentTypes(DataTypes.VARIANT(), DataTypes.STRING().notNull()),
                 TestSpec.forStrategy(
                                 "Validate incorrect variant key for a variant",