move primitive dialect configuration into a struct

src/dialect/ansi.rs

@@ -10,22 +10,25 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::dialect::Dialect;
+use crate::dialect::{Dialect, DialectFlags};
 
 /// A [`Dialect`] for [ANSI SQL](https://en.wikipedia.org/wiki/SQL:2011).
-#[derive(Debug)]
-pub struct AnsiDialect {}
+#[derive(Debug, Default)]
+pub struct AnsiDialect;
 
 impl Dialect for AnsiDialect {
+    fn flags(&self) -> DialectFlags {
+        DialectFlags {
+            require_interval_qualifier: true,
+            ..Default::default()
+        }
+    }
+
     fn is_identifier_start(&self, ch: char) -> bool {
         ch.is_ascii_lowercase() || ch.is_ascii_uppercase()
     }
 
     fn is_identifier_part(&self, ch: char) -> bool {
         ch.is_ascii_lowercase() || ch.is_ascii_uppercase() || ch.is_ascii_digit() || ch == '_'
     }
-
-    fn require_interval_qualifier(&self) -> bool {
-        true
-    }
 }

src/dialect/bigquery.rs

@@ -10,13 +10,33 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::dialect::Dialect;
+use crate::dialect::{Dialect, DialectFlags};
 
 /// A [`Dialect`] for [Google Bigquery](https://cloud.google.com/bigquery/)
 #[derive(Debug, Default)]
 pub struct BigQueryDialect;
 
 impl Dialect for BigQueryDialect {
+    fn flags(&self) -> DialectFlags {
+        DialectFlags {
+            // See https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#quoted_literals
+            supports_triple_quoted_string: true,
+            // See https://cloud.google.com/bigquery/docs/reference/standard-sql/navigation_functions#first_value
+            supports_window_function_null_treatment_arg: true,
+            // See https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#escape_sequences
+            supports_string_literal_backslash_escape: true,
+            // See https://cloud.google.com/bigquery/docs/reference/standard-sql/window-function-calls#ref_named_window
+            supports_window_clause_named_window_reference: true,
+            // See https://cloud.google.com/bigquery/docs/reference/standard-sql/procedural-language#set
+            supports_parenthesized_set_variables: true,
+            // See https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#select_except
+            supports_select_wildcard_except: true,
+            // See https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types#interval_type
+            require_interval_qualifier: true,
+            ..Default::default()
+        }
+    }
+
     // See https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#identifiers
     fn is_delimited_identifier_start(&self, ch: char) -> bool {
         ch == '`'
@@ -33,38 +53,4 @@ impl Dialect for BigQueryDialect {
     fn is_identifier_part(&self, ch: char) -> bool {
         ch.is_ascii_lowercase() || ch.is_ascii_uppercase() || ch.is_ascii_digit() || ch == '_'
     }
-
-    /// See [doc](https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#quoted_literals)
-    fn supports_triple_quoted_string(&self) -> bool {
-        true
-    }
-
-    /// See [doc](https://cloud.google.com/bigquery/docs/reference/standard-sql/navigation_functions#first_value)
-    fn supports_window_function_null_treatment_arg(&self) -> bool {
-        true
-    }
-
-    // See https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#escape_sequences
-    fn supports_string_literal_backslash_escape(&self) -> bool {
-        true
-    }
-
-    /// See [doc](https://cloud.google.com/bigquery/docs/reference/standard-sql/window-function-calls#ref_named_window)
-    fn supports_window_clause_named_window_reference(&self) -> bool {
-        true
-    }
-
-    /// See [doc](https://cloud.google.com/bigquery/docs/reference/standard-sql/procedural-language#set)
-    fn supports_parenthesized_set_variables(&self) -> bool {
-        true
-    }
-
-    // See https://cloud.google.com/bigquery/docs/reference/standard-sql/query-syntax#select_except
-    fn supports_select_wildcard_except(&self) -> bool {
-        true
-    }
-
-    fn require_interval_qualifier(&self) -> bool {
-        true
-    }
 }

src/dialect/clickhouse.rs

@@ -10,13 +10,22 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::dialect::Dialect;
+use crate::dialect::{Dialect, DialectFlags};
 
 // A [`Dialect`] for [ClickHouse](https://clickhouse.com/).
-#[derive(Debug)]
-pub struct ClickHouseDialect {}
+#[derive(Debug, Default)]
+pub struct ClickHouseDialect;
 
 impl Dialect for ClickHouseDialect {
+    fn flags(&self) -> DialectFlags {
+        DialectFlags {
+            supports_string_literal_backslash_escape: true,
+            supports_select_wildcard_except: true,
+            describe_requires_table_keyword: true,
+            require_interval_qualifier: true,
+            ..Default::default()
+        }
+    }
     fn is_identifier_start(&self, ch: char) -> bool {
         // See https://clickhouse.com/docs/en/sql-reference/syntax/#syntax-identifiers
         ch.is_ascii_lowercase() || ch.is_ascii_uppercase() || ch == '_'
@@ -25,20 +34,4 @@ impl Dialect for ClickHouseDialect {
     fn is_identifier_part(&self, ch: char) -> bool {
         self.is_identifier_start(ch) || ch.is_ascii_digit()
     }
-
-    fn supports_string_literal_backslash_escape(&self) -> bool {
-        true
-    }
-
-    fn supports_select_wildcard_except(&self) -> bool {
-        true
-    }
-
-    fn describe_requires_table_keyword(&self) -> bool {
-        true
-    }
-
-    fn require_interval_qualifier(&self) -> bool {
-        true
-    }
 }

src/dialect/databricks.rs

@@ -1,13 +1,25 @@
-use crate::dialect::Dialect;
+use crate::dialect::{Dialect, DialectFlags};
 
 /// A [`Dialect`] for [Databricks SQL](https://www.databricks.com/)
 ///
 /// See <https://docs.databricks.com/en/sql/language-manual/index.html>.
 #[derive(Debug, Default)]
 pub struct DatabricksDialect;
 
+/// see <https://docs.databricks.com/en/sql/language-manual/sql-ref-identifiers.html>
 impl Dialect for DatabricksDialect {
-    // see https://docs.databricks.com/en/sql/language-manual/sql-ref-identifiers.html
+    fn flags(&self) -> DialectFlags {
+        DialectFlags {
+            supports_filter_during_aggregation: true,
+            // https://docs.databricks.com/en/sql/language-manual/sql-ref-syntax-qry-select-groupby.html
+            supports_group_by_expr: true,
+            supports_lambda_functions: true,
+            // https://docs.databricks.com/en/sql/language-manual/sql-ref-syntax-qry-select.html#syntax
+            supports_select_wildcard_except: true,
+            require_interval_qualifier: true,
+            ..Default::default()
+        }
+    }
 
     fn is_delimited_identifier_start(&self, ch: char) -> bool {
         matches!(ch, '`')
@@ -20,26 +32,4 @@ impl Dialect for DatabricksDialect {
     fn is_identifier_part(&self, ch: char) -> bool {
         matches!(ch, 'a'..='z' | 'A'..='Z' | '0'..='9' | '_')
     }
-
-    fn supports_filter_during_aggregation(&self) -> bool {
-        true
-    }
-
-    // https://docs.databricks.com/en/sql/language-manual/sql-ref-syntax-qry-select-groupby.html
-    fn supports_group_by_expr(&self) -> bool {
-        true
-    }
-
-    fn supports_lambda_functions(&self) -> bool {
-        true
-    }
-
-    // https://docs.databricks.com/en/sql/language-manual/sql-ref-syntax-qry-select.html#syntax
-    fn supports_select_wildcard_except(&self) -> bool {
-        true
-    }
-
-    fn require_interval_qualifier(&self) -> bool {
-        true
-    }
 }

src/dialect/duckdb.rs

@@ -10,16 +10,30 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::dialect::Dialect;
+use crate::dialect::{Dialect, DialectFlags};
 
 /// A [`Dialect`] for [DuckDB](https://duckdb.org/)
 #[derive(Debug, Default)]
 pub struct DuckDbDialect;
 
 // In most cases the redshift dialect is identical to [`PostgresSqlDialect`].
 impl Dialect for DuckDbDialect {
-    fn supports_trailing_commas(&self) -> bool {
-        true
+    fn flags(&self) -> DialectFlags {
+        DialectFlags {
+            supports_trailing_commas: true,
+            supports_filter_during_aggregation: true,
+            supports_group_by_expr: true,
+            supports_named_fn_args_with_eq_operator: true,
+            // DuckDB uses this syntax for `STRUCT`s.
+            //
+            // https://duckdb.org/docs/sql/data_types/struct.html#creating-structs
+            supports_dictionary_syntax: true,
+            // DuckDB uses this syntax for `MAP`s.
+            //
+            // https://duckdb.org/docs/sql/data_types/map.html#creating-maps
+            support_map_literal_syntax: true,
+            ..Default::default()
+        }
     }
 
     fn is_identifier_start(&self, ch: char) -> bool {
@@ -29,30 +43,4 @@ impl Dialect for DuckDbDialect {
     fn is_identifier_part(&self, ch: char) -> bool {
         ch.is_alphabetic() || ch.is_ascii_digit() || ch == '$' || ch == '_'
     }
-
-    fn supports_filter_during_aggregation(&self) -> bool {
-        true
-    }
-
-    fn supports_group_by_expr(&self) -> bool {
-        true
-    }
-
-    fn supports_named_fn_args_with_eq_operator(&self) -> bool {
-        true
-    }
-
-    // DuckDB uses this syntax for `STRUCT`s.
-    //
-    // https://duckdb.org/docs/sql/data_types/struct.html#creating-structs
-    fn supports_dictionary_syntax(&self) -> bool {
-        true
-    }
-
-    // DuckDB uses this syntax for `MAP`s.
-    //
-    // https://duckdb.org/docs/sql/data_types/map.html#creating-maps
-    fn support_map_literal_syntax(&self) -> bool {
-        true
-    }
 }

src/dialect/generic.rs

@@ -10,14 +10,33 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use crate::dialect::Dialect;
+use crate::dialect::{Dialect, DialectFlags};
 
 /// A permissive, general purpose [`Dialect`], which parses a wide variety of SQL
 /// statements, from many different dialects.
 #[derive(Debug, Default)]
 pub struct GenericDialect;
 
 impl Dialect for GenericDialect {
+    fn flags(&self) -> DialectFlags {
+        DialectFlags {
+            supports_unicode_string_literal: true,
+            supports_group_by_expr: true,
+            supports_connect_by: true,
+            supports_match_recognize: true,
+            supports_start_transaction_modifier: true,
+            supports_window_function_null_treatment_arg: true,
+            supports_dictionary_syntax: true,
+            supports_window_clause_named_window_reference: true,
+            supports_parenthesized_set_variables: true,
+            supports_select_wildcard_except: true,
+            support_map_literal_syntax: true,
+            allow_extract_custom: true,
+            allow_extract_single_quotes: true,
+            supports_create_index_with_clause: true,
+            ..Default::default()
+        }
+    }
     fn is_delimited_identifier_start(&self, ch: char) -> bool {
         ch == '"' || ch == '`'
     }
@@ -34,60 +53,4 @@ impl Dialect for GenericDialect {
             || ch == '#'
             || ch == '_'
     }
-
-    fn supports_unicode_string_literal(&self) -> bool {
-        true
-    }
-
-    fn supports_group_by_expr(&self) -> bool {
-        true
-    }
-
-    fn supports_connect_by(&self) -> bool {
-        true
-    }
-
-    fn supports_match_recognize(&self) -> bool {
-        true
-    }
-
-    fn supports_start_transaction_modifier(&self) -> bool {
-        true
-    }
-
-    fn supports_window_function_null_treatment_arg(&self) -> bool {
-        true
-    }
-
-    fn supports_dictionary_syntax(&self) -> bool {
-        true
-    }
-
-    fn supports_window_clause_named_window_reference(&self) -> bool {
-        true
-    }
-
-    fn supports_parenthesized_set_variables(&self) -> bool {
-        true
-    }
-
-    fn supports_select_wildcard_except(&self) -> bool {
-        true
-    }
-
-    fn support_map_literal_syntax(&self) -> bool {
-        true
-    }
-
-    fn allow_extract_custom(&self) -> bool {
-        true
-    }
-
-    fn allow_extract_single_quotes(&self) -> bool {
-        true
-    }
-
-    fn supports_create_index_with_clause(&self) -> bool {
-        true
-    }
 }