databend-common-ast 0.2.5

// Copyright 2021 Datafuse Labs
//
// 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 nom::Parser;
use nom_rule::rule;

use super::common::ident;
use super::expr::literal_string;
use super::expr::literal_u64;
use super::statement::parse_create_option;
use crate::ast::CreateSequenceStmt;
use crate::ast::DropSequenceStmt;
use crate::ast::Statement;
use crate::parser::common::IResult;
use crate::parser::common::map_res;
use crate::parser::common::*;
use crate::parser::input::Input;
use crate::parser::statement::show_options;
use crate::parser::token::*;

pub fn sequence(i: Input) -> IResult<Statement> {
    rule!(
         #create_sequence: "`CREATE [OR REPLACE] SEQUENCE [IF NOT EXISTS] <sequence_name> [START = <initial_value>] [INCREMENT = <sequence_interval>] [COMMENT = '<string_literal>']`"
         | #drop_sequence: "`DROP [IF EXISTS] <sequence_name>`"
         | #show_sequences: "`SHOW SEQUENCES [<show_limit>]`"
         | #desc_sequence: "`DESCRIBE SEQUENCE <sequence_name>`"
    ).parse(i)
}

fn create_sequence(i: Input) -> IResult<Statement> {
    map_res(
        rule! {
            CREATE ~ ( OR ~ ^REPLACE )? ~ SEQUENCE ~ ( IF ~ ^NOT ~ ^EXISTS )?
            ~ #ident
            ~ ( START ~ ( WITH | "=" )? ~ #literal_u64 )?
            ~ ( INCREMENT ~ ( BY | "=" )? ~ #literal_u64 )?
            ~ ( COMMENT ~ "=" ~ #literal_string )?
        },
        |(
            _,
            opt_or_replace,
            _,
            opt_if_not_exists,
            sequence,
            opt_start,
            opt_increment,
            opt_comment,
        )| {
            let create_option =
                parse_create_option(opt_or_replace.is_some(), opt_if_not_exists.is_some())?;

            Ok(Statement::CreateSequence(CreateSequenceStmt {
                create_option,
                sequence,
                start: opt_start.map(|(_, _, start)| start),
                increment: opt_increment.map(|(_, _, start)| start),
                comment: opt_comment.map(|(_, _, comment)| comment),
            }))
        },
    )(i)
}

fn drop_sequence(i: Input) -> IResult<Statement> {
    map_res(
        rule! {
            DROP ~ SEQUENCE ~ ( IF ~ ^EXISTS )? ~ #ident
        },
        |(_, _, opt_if_exists, sequence)| {
            Ok(Statement::DropSequence(DropSequenceStmt {
                sequence,
                if_exists: opt_if_exists.is_some(),
            }))
        },
    )(i)
}

fn show_sequences(i: Input) -> IResult<Statement> {
    map_res(
        rule! {
            SHOW ~ SEQUENCES ~ #show_options?
        },
        |(_, _, show_options)| Ok(Statement::ShowSequences { show_options }),
    )(i)
}

fn desc_sequence(i: Input) -> IResult<Statement> {
    map_res(
        rule! {
            ( DESC | DESCRIBE ) ~ SEQUENCE ~ #ident
        },
        |(_, _, name)| Ok(Statement::DescSequence { name }),
    )(i)
}