bigquery.rs

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use crate::dialect::{Dialect, DialectFlags};

/// A [`Dialect`] for [Google Bigquery](https://cloud.google.com/bigquery/)
#[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 == '`'
    }

    fn supports_projection_trailing_commas(&self) -> bool {
        true
    }

    fn is_identifier_start(&self, ch: char) -> bool {
        ch.is_ascii_lowercase() || ch.is_ascii_uppercase() || ch == '_'
    }

    fn is_identifier_part(&self, ch: char) -> bool {
        ch.is_ascii_lowercase() || ch.is_ascii_uppercase() || ch.is_ascii_digit() || ch == '_'
    }
}