move primitive dialect configuration into a struct

README.md

@@ -24,7 +24,7 @@ let sql = "SELECT a, b, 123, myfunc(b) \
            WHERE a > b AND b < 100 \
            ORDER BY a DESC, b";
 
-let dialect = GenericDialect {}; // or AnsiDialect, or your own dialect ...
+let dialect = GenericDialect::default(); // or AnsiDialect, or your own dialect ...
 
 let ast = Parser::parse_sql(&dialect, sql).unwrap();
 

examples/cli.rs

@@ -37,18 +37,18 @@ $ cargo run --feature json_example --example cli FILENAME.sql [--dialectname]
     );
 
     let dialect: Box<dyn Dialect> = match std::env::args().nth(2).unwrap_or_default().as_ref() {
-        "--ansi" => Box::new(AnsiDialect {}),
-        "--bigquery" => Box::new(BigQueryDialect {}),
-        "--postgres" => Box::new(PostgreSqlDialect {}),
-        "--ms" => Box::new(MsSqlDialect {}),
-        "--mysql" => Box::new(MySqlDialect {}),
-        "--snowflake" => Box::new(SnowflakeDialect {}),
-        "--hive" => Box::new(HiveDialect {}),
-        "--redshift" => Box::new(RedshiftSqlDialect {}),
-        "--clickhouse" => Box::new(ClickHouseDialect {}),
-        "--duckdb" => Box::new(DuckDbDialect {}),
-        "--sqlite" => Box::new(SQLiteDialect {}),
-        "--generic" | "" => Box::new(GenericDialect {}),
+        "--ansi" => Box::new(AnsiDialect::default()),
+        "--bigquery" => Box::new(BigQueryDialect::default()),
+        "--postgres" => Box::new(PostgreSqlDialect::default()),
+        "--ms" => Box::new(MsSqlDialect::default()),
+        "--mysql" => Box::new(MySqlDialect::default()),
+        "--snowflake" => Box::new(SnowflakeDialect::default()),
+        "--hive" => Box::new(HiveDialect::default()),
+        "--redshift" => Box::new(RedshiftSqlDialect::default()),
+        "--clickhouse" => Box::new(ClickHouseDialect::default()),
+        "--duckdb" => Box::new(DuckDbDialect::default()),
+        "--sqlite" => Box::new(SQLiteDialect::default()),
+        "--generic" | "" => Box::new(GenericDialect::default()),
         s => panic!("Unexpected parameter: {s}"),
     };
 

examples/parse_select.rs

@@ -21,7 +21,7 @@ fn main() {
                WHERE a > b AND b < 100 \
                ORDER BY a DESC, b";
 
-    let dialect = GenericDialect {};
+    let dialect = GenericDialect::default();
 
     let ast = Parser::parse_sql(&dialect, sql).unwrap();
 

fuzz/fuzz_targets/fuzz_parse_sql.rs

@@ -5,7 +5,7 @@ use sqlparser::parser::Parser;
 fn main() {
     loop {
         fuzz!(|data: String| {
-            let dialect = GenericDialect {};
+            let dialect = GenericDialect::default();
             let _ = Parser::parse_sql(&dialect, &data);
         });
     }

sqlparser_bench/benches/sqlparser_bench.rs

@@ -16,7 +16,7 @@ use sqlparser::parser::Parser;
 
 fn basic_queries(c: &mut Criterion) {
     let mut group = c.benchmark_group("sqlparser-rs parsing benchmark");
-    let dialect = GenericDialect {};
+    let dialect = GenericDialect::default();
 
     let string = "SELECT * FROM table WHERE 1 = 1";
     group.bench_function("sqlparser::select", |b| {

src/ast/visitor.rs

@@ -155,7 +155,7 @@ visit_noop!(bigdecimal::BigDecimal);
 /// }
 ///
 /// let sql = "SELECT a FROM foo where x IN (SELECT y FROM bar)";
-/// let statements = Parser::parse_sql(&GenericDialect{}, sql)
+/// let statements = Parser::parse_sql(&GenericDialect::default(), sql)
 ///    .unwrap();
 ///
 /// // Drive the visitor through the AST
@@ -266,7 +266,7 @@ pub trait Visitor {
 /// }
 ///
 /// let sql = "SELECT to_replace FROM foo where to_replace IN (SELECT to_replace FROM bar)";
-/// let mut statements = Parser::parse_sql(&GenericDialect{}, sql).unwrap();
+/// let mut statements = Parser::parse_sql(&GenericDialect::default(), sql).unwrap();
 ///
 /// // Drive the visitor through the AST
 /// statements.visit(&mut Replacer);
@@ -361,7 +361,7 @@ impl<E, F: FnMut(&mut ObjectName) -> ControlFlow<E>> VisitorMut for RelationVisi
 /// # use sqlparser::ast::{visit_relations};
 /// # use core::ops::ControlFlow;
 /// let sql = "SELECT a FROM foo where x IN (SELECT y FROM bar)";
-/// let statements = Parser::parse_sql(&GenericDialect{}, sql)
+/// let statements = Parser::parse_sql(&GenericDialect::default(), sql)
 ///    .unwrap();
 ///
 /// // visit statements, capturing relations (table names)
@@ -401,7 +401,7 @@ where
 /// # use sqlparser::ast::{ObjectName, visit_relations_mut};
 /// # use core::ops::ControlFlow;
 /// let sql = "SELECT a FROM foo";
-/// let mut statements = Parser::parse_sql(&GenericDialect{}, sql)
+/// let mut statements = Parser::parse_sql(&GenericDialect::default(), sql)
 ///    .unwrap();
 ///
 /// // visit statements, renaming table foo to bar
@@ -449,7 +449,7 @@ impl<E, F: FnMut(&mut Expr) -> ControlFlow<E>> VisitorMut for ExprVisitor<F> {
 /// # use sqlparser::ast::{visit_expressions};
 /// # use core::ops::ControlFlow;
 /// let sql = "SELECT a FROM foo where x IN (SELECT y FROM bar)";
-/// let statements = Parser::parse_sql(&GenericDialect{}, sql)
+/// let statements = Parser::parse_sql(&GenericDialect::default(), sql)
 ///    .unwrap();
 ///
 /// // visit all expressions
@@ -493,7 +493,7 @@ where
 /// # use sqlparser::ast::{Expr, visit_expressions_mut, visit_statements_mut};
 /// # use core::ops::ControlFlow;
 /// let sql = "SELECT (SELECT y FROM z LIMIT 9) FROM t LIMIT 3";
-/// let mut statements = Parser::parse_sql(&GenericDialect{}, sql).unwrap();
+/// let mut statements = Parser::parse_sql(&GenericDialect::default(), sql).unwrap();
 ///
 /// // Remove all select limits in sub-queries
 /// visit_expressions_mut(&mut statements, |expr| {
@@ -518,7 +518,7 @@ where
 /// # use sqlparser::ast::*;
 /// # use core::ops::ControlFlow;
 /// let sql = "SELECT x, y FROM t";
-/// let mut statements = Parser::parse_sql(&GenericDialect{}, sql).unwrap();
+/// let mut statements = Parser::parse_sql(&GenericDialect::default(), sql).unwrap();
 ///
 /// visit_expressions_mut(&mut statements, |expr| {
 ///   if matches!(expr, Expr::Identifier(col_name) if col_name.value == "x") {
@@ -579,7 +579,7 @@ impl<E, F: FnMut(&mut Statement) -> ControlFlow<E>> VisitorMut for StatementVisi
 /// # use sqlparser::ast::{visit_statements};
 /// # use core::ops::ControlFlow;
 /// let sql = "SELECT a FROM foo where x IN (SELECT y FROM bar); CREATE TABLE baz(q int)";
-/// let statements = Parser::parse_sql(&GenericDialect{}, sql)
+/// let statements = Parser::parse_sql(&GenericDialect::default(), sql)
 ///    .unwrap();
 ///
 /// // visit all statements
@@ -616,7 +616,7 @@ where
 /// # use sqlparser::ast::{Statement, visit_statements_mut};
 /// # use core::ops::ControlFlow;
 /// let sql = "SELECT x FROM foo LIMIT 9+$limit; SELECT * FROM t LIMIT f()";
-/// let mut statements = Parser::parse_sql(&GenericDialect{}, sql).unwrap();
+/// let mut statements = Parser::parse_sql(&GenericDialect::default(), sql).unwrap();
 ///
 /// // Remove all select limits in outer statements (not in sub-queries)
 /// visit_statements_mut(&mut statements, |stmt| {
@@ -715,7 +715,7 @@ mod tests {
     }
 
     fn do_visit(sql: &str) -> Vec<String> {
-        let dialect = GenericDialect {};
+        let dialect = GenericDialect::default();
         let tokens = Tokenizer::new(&dialect, sql).tokenize().unwrap();
         let s = Parser::new(&dialect)
             .with_tokens(tokens)

src/dialect/ansi.rs

@@ -10,22 +10,31 @@
 // 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 {}
+pub struct AnsiDialect(DialectFlags);
+
+impl Default for AnsiDialect {
+    fn default() -> Self {
+        Self(DialectFlags {
+            require_interval_qualifier: true,
+            ..Default::default()
+        })
+    }
+}
 
 impl Dialect for AnsiDialect {
+    fn flags(&self) -> &DialectFlags {
+        &self.0
+    }
+
     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 +10,39 @@
 // 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;
+#[derive(Debug)]
+pub struct BigQueryDialect(DialectFlags);
+
+impl Default for BigQueryDialect {
+    fn default() -> Self {
+        Self(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()
+        })
+    }
+}
 
 impl Dialect for BigQueryDialect {
+    fn flags(&self) -> &DialectFlags {
+        &self.0
+    }
+
     // See https://cloud.google.com/bigquery/docs/reference/standard-sql/lexical#identifiers
     fn is_delimited_identifier_start(&self, ch: char) -> bool {
         ch == '`'
@@ -33,38 +59,4 @@ 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 +10,29 @@
 // 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 {}
+pub struct ClickHouseDialect(DialectFlags);
+
+impl Default for ClickHouseDialect {
+    fn default() -> Self {
+        Self(DialectFlags {
+            supports_string_literal_backslash_escape: true,
+            supports_select_wildcard_except: true,
+            describe_requires_table_keyword: true,
+            require_interval_qualifier: true,
+            ..Default::default()
+        })
+    }
+}
 
 impl Dialect for ClickHouseDialect {
+    fn flags(&self) -> &DialectFlags {
+        &self.0
+    }
+
     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 +41,4 @@ 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 +1,31 @@
-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;
+#[derive(Debug)]
+pub struct DatabricksDialect(DialectFlags);
+
+impl Default for DatabricksDialect {
+    fn default() -> Self {
+        Self(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()
+        })
+    }
+}
 
+/// 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 {
+        &self.0
+    }
 
     fn is_delimited_identifier_start(&self, ch: char) -> bool {
         matches!(ch, '`')
@@ -20,26 +38,4 @@ 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
-    }
 }