Allow raw SQL subqueries without surrounding brackets

Related to #247
Related to #225
Related to #1319

lib/src/sql/ending.rs

@@ -1,13 +1,16 @@
 use crate::sql::comment::comment;
+use crate::sql::comment::shouldbespace;
 use crate::sql::error::IResult;
 use crate::sql::operator::{assigner, operator};
 use nom::branch::alt;
 use nom::bytes::complete::tag;
+use nom::bytes::complete::tag_no_case;
 use nom::character::complete::char;
 use nom::character::complete::multispace1;
 use nom::combinator::eof;
 use nom::combinator::map;
 use nom::combinator::peek;
+use nom::sequence::preceded;
 
 pub fn number(i: &str) -> IResult<&str, ()> {
 	peek(alt((
@@ -62,3 +65,17 @@ pub fn duration(i: &str) -> IResult<&str, ()> {
 		map(eof, |_| ()),
 	)))(i)
 }
+
+pub fn subquery(i: &str) -> IResult<&str, ()> {
+	peek(alt((
+		map(preceded(shouldbespace, tag_no_case("THEN")), |_| ()),
+		map(preceded(shouldbespace, tag_no_case("ELSE")), |_| ()),
+		map(preceded(shouldbespace, tag_no_case("END")), |_| ()),
+		map(comment, |_| ()),
+		map(char(']'), |_| ()),
+		map(char('}'), |_| ()),
+		map(char(';'), |_| ()),
+		map(char(','), |_| ()),
+		map(eof, |_| ()),
+	)))(i)
+}

lib/src/sql/subquery.rs

@@ -3,6 +3,7 @@ use crate::dbs::Options;
 use crate::dbs::Transaction;
 use crate::err::Error;
 use crate::sql::comment::mightbespace;
+use crate::sql::ending::subquery as ending;
 use crate::sql::error::IResult;
 use crate::sql::statements::create::{create, CreateStatement};
 use crate::sql::statements::delete::{delete, DeleteStatement};
@@ -222,7 +223,7 @@ impl Display for Subquery {
 }
 
 pub fn subquery(i: &str) -> IResult<&str, Subquery> {
-	alt((subquery_ifelse, subquery_others))(i)
+	alt((subquery_ifelse, subquery_other, subquery_value))(i)
 }
 
 fn subquery_ifelse(i: &str) -> IResult<&str, Subquery> {
@@ -230,10 +231,35 @@ fn subquery_ifelse(i: &str) -> IResult<&str, Subquery> {
 	Ok((i, v))
 }
 
-fn subquery_others(i: &str) -> IResult<&str, Subquery> {
+fn subquery_value(i: &str) -> IResult<&str, Subquery> {
 	let (i, _) = char('(')(i)?;
 	let (i, _) = mightbespace(i)?;
-	let (i, v) = alt((
+	let (i, v) = map(value, Subquery::Value)(i)?;
+	let (i, _) = mightbespace(i)?;
+	let (i, _) = char(')')(i)?;
+	Ok((i, v))
+}
+
+fn subquery_other(i: &str) -> IResult<&str, Subquery> {
+	alt((
+		|i| {
+			let (i, _) = char('(')(i)?;
+			let (i, _) = mightbespace(i)?;
+			let (i, v) = subquery_inner(i)?;
+			let (i, _) = mightbespace(i)?;
+			let (i, _) = char(')')(i)?;
+			Ok((i, v))
+		},
+		|i| {
+			let (i, v) = subquery_inner(i)?;
+			let (i, _) = ending(i)?;
+			Ok((i, v))
+		},
+	))(i)
+}
+
+fn subquery_inner(i: &str) -> IResult<&str, Subquery> {
+	alt((
 		map(output, Subquery::Output),
 		map(select, Subquery::Select),
 		map(create, Subquery::Create),
@@ -241,11 +267,7 @@ fn subquery_others(i: &str) -> IResult<&str, Subquery> {
 		map(delete, Subquery::Delete),
 		map(relate, Subquery::Relate),
 		map(insert, Subquery::Insert),
-		map(value, Subquery::Value),
+	))(i)
-	))(i)?;
-	let (i, _) = mightbespace(i)?;
-	let (i, _) = char(')')(i)?;
-	Ok((i, v))
 }
 
 #[cfg(test)]

lib/tests/subquery.rs

@@ -110,19 +110,19 @@ async fn subquery_ifelse() -> Result<(), Error> {
 		RETURN $record;
 		-- Update the record field if it exists
 		IF $record.count THEN
-			( UPDATE person:test SET sport += 'football' RETURN sport )
+			(UPDATE person:test SET sport += 'football' RETURN sport)
 		ELSE
-			( UPDATE person:test SET sport = ['basketball'] RETURN sport )
+			(UPDATE person:test SET sport = ['basketball'] RETURN sport)
 		END;
 		-- Check if the record exists
-		LET $record = (SELECT *, count() AS count FROM person:test);
+		LET $record = SELECT *, count() AS count FROM person:test;
 		-- Return the specified record
 		RETURN $record;
 		-- Update the record field if it exists
 		IF $record.count THEN
-			( UPDATE person:test SET sport += 'football' RETURN sport )
+			UPDATE person:test SET sport += 'football' RETURN sport
 		ELSE
-			( UPDATE person:test SET sport = ['basketball'] RETURN sport )
+			UPDATE person:test SET sport = ['basketball'] RETURN sport
 		END;
 	";
 	let dbs = Datastore::new("memory").await?;