feat: dollar-quoted strings support (#772)

* feat: support dollar-quoted strings

* remove comment

* unused code

* removed debugging

* added tests

* fmt

* clippy

* updated tests

src/ast/mod.rs

@@ -39,7 +39,9 @@ pub use self::query::{
     SelectInto, SelectItem, SetExpr, SetOperator, SetQuantifier, Table, TableAlias, TableFactor,
     TableWithJoins, Top, Values, WildcardAdditionalOptions, With,
 };
-pub use self::value::{escape_quoted_string, DateTimeField, TrimWhereField, Value};
+pub use self::value::{
+    escape_quoted_string, DateTimeField, DollarQuotedString, TrimWhereField, Value,
+};
 
 #[cfg(feature = "visitor")]
 pub use visitor::*;

src/ast/value.rs

@@ -35,6 +35,8 @@ pub enum Value {
     Number(BigDecimal, bool),
     /// 'string value'
     SingleQuotedString(String),
+    // $<tag_name>$string value$<tag_name>$ (postgres syntax)
+    DollarQuotedString(DollarQuotedString),
     /// e'string value' (postgres extension)
     /// <https://www.postgresql.org/docs/8.3/sql-syntax-lexical.html#SQL-SYNTAX-STRINGS
     EscapedStringLiteral(String),
@@ -60,6 +62,7 @@ impl fmt::Display for Value {
             Value::Number(v, l) => write!(f, "{}{long}", v, long = if *l { "L" } else { "" }),
             Value::DoubleQuotedString(v) => write!(f, "\"{}\"", v),
             Value::SingleQuotedString(v) => write!(f, "'{}'", escape_single_quote_string(v)),
+            Value::DollarQuotedString(v) => write!(f, "{}", v),
             Value::EscapedStringLiteral(v) => write!(f, "E'{}'", escape_escaped_string(v)),
             Value::NationalStringLiteral(v) => write!(f, "N'{}'", v),
             Value::HexStringLiteral(v) => write!(f, "X'{}'", v),
@@ -71,6 +74,27 @@ impl fmt::Display for Value {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, PartialOrd, Eq, Ord, Hash)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "visitor", derive(Visit))]
+pub struct DollarQuotedString {
+    pub value: String,
+    pub tag: Option<String>,
+}
+
+impl fmt::Display for DollarQuotedString {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match &self.tag {
+            Some(tag) => {
+                write!(f, "${}${}${}$", tag, self.value, tag)
+            }
+            None => {
+                write!(f, "$${}$$", self.value)
+            }
+        }
+    }
+}
+
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Ord, PartialOrd, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "visitor", derive(Visit))]

src/parser.rs

@@ -778,6 +778,7 @@ impl<'a> Parser<'a> {
             Token::Number(_, _)
             | Token::SingleQuotedString(_)
             | Token::DoubleQuotedString(_)
+            | Token::DollarQuotedString(_)
             | Token::NationalStringLiteral(_)
             | Token::HexStringLiteral(_) => {
                 self.prev_token();
@@ -4104,6 +4105,7 @@ impl<'a> Parser<'a> {
             },
             Token::SingleQuotedString(ref s) => Ok(Value::SingleQuotedString(s.to_string())),
             Token::DoubleQuotedString(ref s) => Ok(Value::DoubleQuotedString(s.to_string())),
+            Token::DollarQuotedString(ref s) => Ok(Value::DollarQuotedString(s.clone())),
             Token::NationalStringLiteral(ref s) => Ok(Value::NationalStringLiteral(s.to_string())),
             Token::EscapedStringLiteral(ref s) => Ok(Value::EscapedStringLiteral(s.to_string())),
             Token::HexStringLiteral(ref s) => Ok(Value::HexStringLiteral(s.to_string())),
@@ -4148,24 +4150,9 @@ impl<'a> Parser<'a> {
     pub fn parse_function_definition(&mut self) -> Result<FunctionDefinition, ParserError> {
         let peek_token = self.peek_token();
         match peek_token.token {
-            Token::DoubleDollarQuoting if dialect_of!(self is PostgreSqlDialect) => {
+            Token::DollarQuotedString(value) if dialect_of!(self is PostgreSqlDialect) => {
                 self.next_token();
-                let mut func_desc = String::new();
-                loop {
-                    if let Some(next_token) = self.next_token_no_skip() {
-                        match &next_token.token {
-                            Token::DoubleDollarQuoting => break,
-                            Token::EOF => {
-                                return self.expected(
-                                    "literal string",
-                                    TokenWithLocation::wrap(Token::EOF),
-                                );
-                            }
-                            token => func_desc.push_str(token.to_string().as_str()),
-                        }
-                    }
-                }
-                Ok(FunctionDefinition::DoubleDollarDef(func_desc))
+                Ok(FunctionDefinition::DoubleDollarDef(value.value))
             }
             _ => Ok(FunctionDefinition::SingleQuotedDef(
                 self.parse_literal_string()?,
@@ -4712,7 +4699,7 @@ impl<'a> Parser<'a> {
     }
 
     /// Parse a query expression, i.e. a `SELECT` statement optionally
-    /// preceeded with some `WITH` CTE declarations and optionally followed
+    /// preceded with some `WITH` CTE declarations and optionally followed
     /// by `ORDER BY`. Unlike some other parse_... methods, this one doesn't
     /// expect the initial keyword to be already consumed
     pub fn parse_query(&mut self) -> Result<Query, ParserError> {

src/tokenizer.rs

@@ -34,6 +34,7 @@ use serde::{Deserialize, Serialize};
 #[cfg(feature = "visitor")]
 use sqlparser_derive::Visit;
 
+use crate::ast::DollarQuotedString;
 use crate::dialect::SnowflakeDialect;
 use crate::dialect::{Dialect, MySqlDialect};
 use crate::keywords::{Keyword, ALL_KEYWORDS, ALL_KEYWORDS_INDEX};
@@ -55,6 +56,8 @@ pub enum Token {
     SingleQuotedString(String),
     /// Double quoted string: i.e: "string"
     DoubleQuotedString(String),
+    /// Dollar quoted string: i.e: $$string$$ or $tag_name$string$tag_name$
+    DollarQuotedString(DollarQuotedString),
     /// "National" string literal: i.e: N'string'
     NationalStringLiteral(String),
     /// "escaped" string literal, which are an extension to the SQL standard: i.e: e'first \n second' or E 'first \n second'
@@ -149,8 +152,6 @@ pub enum Token {
     PGCubeRoot,
     /// `?` or `$` , a prepared statement arg placeholder
     Placeholder(String),
-    /// `$$`, used for PostgreSQL create function definition
-    DoubleDollarQuoting,
     /// ->, used as a operator to extract json field in PostgreSQL
     Arrow,
     /// ->>, used as a operator to extract json field as text in PostgreSQL
@@ -184,6 +185,7 @@ impl fmt::Display for Token {
             Token::Char(ref c) => write!(f, "{}", c),
             Token::SingleQuotedString(ref s) => write!(f, "'{}'", s),
             Token::DoubleQuotedString(ref s) => write!(f, "\"{}\"", s),
+            Token::DollarQuotedString(ref s) => write!(f, "{}", s),
             Token::NationalStringLiteral(ref s) => write!(f, "N'{}'", s),
             Token::EscapedStringLiteral(ref s) => write!(f, "E'{}'", s),
             Token::HexStringLiteral(ref s) => write!(f, "X'{}'", s),
@@ -236,7 +238,6 @@ impl fmt::Display for Token {
             Token::HashArrow => write!(f, "#>"),
             Token::HashLongArrow => write!(f, "#>>"),
             Token::AtArrow => write!(f, "@>"),
-            Token::DoubleDollarQuoting => write!(f, "$$"),
             Token::ArrowAt => write!(f, "<@"),
             Token::HashMinus => write!(f, "#-"),
             Token::AtQuestion => write!(f, "@?"),
@@ -837,17 +838,8 @@ impl<'a> Tokenizer<'a> {
                     let s = peeking_take_while(chars, |ch| ch.is_numeric());
                     Ok(Some(Token::Placeholder(String::from("?") + &s)))
                 }
-                '$' => {
-                    chars.next();
-                    match chars.peek() {
-                        Some('$') => self.consume_and_return(chars, Token::DoubleDollarQuoting),
-                        _ => {
-                            let s =
-                                peeking_take_while(chars, |ch| ch.is_alphanumeric() || ch == '_');
-                            Ok(Some(Token::Placeholder(String::from("$") + &s)))
-                        }
-                    }
-                }
+                '$' => Ok(Some(self.tokenize_dollar_preceded_value(chars)?)),
+
                 //whitespace check (including unicode chars) should be last as it covers some of the chars above
                 ch if ch.is_whitespace() => {
                     self.consume_and_return(chars, Token::Whitespace(Whitespace::Space))
@@ -858,6 +850,97 @@ impl<'a> Tokenizer<'a> {
         }
     }
 
+    /// Tokenize dollar preceded value (i.e: a string/placeholder)
+    fn tokenize_dollar_preceded_value(&self, chars: &mut State) -> Result<Token, TokenizerError> {
+        let mut s = String::new();
+        let mut value = String::new();
+
+        chars.next();
+
+        if let Some('$') = chars.peek() {
+            chars.next();
+
+            let mut is_terminated = false;
+            let mut prev: Option<char> = None;
+
+            while let Some(&ch) = chars.peek() {
+                if prev == Some('$') {
+                    if ch == '$' {
+                        chars.next();
+                        is_terminated = true;
+                        break;
+                    } else {
+                        s.push('$');
+                        s.push(ch);
+                    }
+                } else if ch != '$' {
+                    s.push(ch);
+                }
+
+                prev = Some(ch);
+                chars.next();
+            }
+
+            return if chars.peek().is_none() && !is_terminated {
+                self.tokenizer_error(chars.location(), "Unterminated dollar-quoted string")
+            } else {
+                Ok(Token::DollarQuotedString(DollarQuotedString {
+                    value: s,
+                    tag: None,
+                }))
+            };
+        } else {
+            value.push_str(&peeking_take_while(chars, |ch| {
+                ch.is_alphanumeric() || ch == '_'
+            }));
+
+            if let Some('$') = chars.peek() {
+                chars.next();
+                s.push_str(&peeking_take_while(chars, |ch| ch != '$'));
+
+                match chars.peek() {
+                    Some('$') => {
+                        chars.next();
+                        for (_, c) in value.chars().enumerate() {
+                            let next_char = chars.next();
+                            if Some(c) != next_char {
+                                return self.tokenizer_error(
+                                    chars.location(),
+                                    format!(
+                                        "Unterminated dollar-quoted string at or near \"{}\"",
+                                        value
+                                    ),
+                                );
+                            }
+                        }
+
+                        if let Some('$') = chars.peek() {
+                            chars.next();
+                        } else {
+                            return self.tokenizer_error(
+                                chars.location(),
+                                "Unterminated dollar-quoted string, expected $",
+                            );
+                        }
+                    }
+                    _ => {
+                        return self.tokenizer_error(
+                            chars.location(),
+                            "Unterminated dollar-quoted, expected $",
+                        );
+                    }
+                }
+            } else {
+                return Ok(Token::Placeholder(String::from("$") + &value));
+            }
+        }
+
+        Ok(Token::DollarQuotedString(DollarQuotedString {
+            value: s,
+            tag: if value.is_empty() { None } else { Some(value) },
+        }))
+    }
+
     fn tokenizer_error<R>(
         &self,
         loc: Location,

tests/sqlparser_postgres.rs

@@ -2507,3 +2507,84 @@ fn parse_drop_function() {
         }
     );
 }
+
+#[test]
+fn parse_dollar_quoted_string() {
+    let sql = "SELECT $$hello$$, $tag_name$world$tag_name$, $$Foo$Bar$$, $$Foo$Bar$$col_name, $$$$, $tag_name$$tag_name$";
+
+    let stmt = pg().parse_sql_statements(sql).unwrap();
+
+    let projection = match stmt.get(0).unwrap() {
+        Statement::Query(query) => match &*query.body {
+            SetExpr::Select(select) => &select.projection,
+            _ => unreachable!(),
+        },
+        _ => unreachable!(),
+    };
+
+    assert_eq!(
+        &Expr::Value(Value::DollarQuotedString(DollarQuotedString {
+            tag: None,
+            value: "hello".into()
+        })),
+        expr_from_projection(&projection[0])
+    );
+
+    assert_eq!(
+        &Expr::Value(Value::DollarQuotedString(DollarQuotedString {
+            tag: Some("tag_name".into()),
+            value: "world".into()
+        })),
+        expr_from_projection(&projection[1])
+    );
+
+    assert_eq!(
+        &Expr::Value(Value::DollarQuotedString(DollarQuotedString {
+            tag: None,
+            value: "Foo$Bar".into()
+        })),
+        expr_from_projection(&projection[2])
+    );
+
+    assert_eq!(
+        projection[3],
+        SelectItem::ExprWithAlias {
+            expr: Expr::Value(Value::DollarQuotedString(DollarQuotedString {
+                tag: None,
+                value: "Foo$Bar".into(),
+            })),
+            alias: Ident {
+                value: "col_name".into(),
+                quote_style: None,
+            },
+        }
+    );
+
+    assert_eq!(
+        expr_from_projection(&projection[4]),
+        &Expr::Value(Value::DollarQuotedString(DollarQuotedString {
+            tag: None,
+            value: "".into()
+        })),
+    );
+
+    assert_eq!(
+        expr_from_projection(&projection[5]),
+        &Expr::Value(Value::DollarQuotedString(DollarQuotedString {
+            tag: Some("tag_name".into()),
+            value: "".into()
+        })),
+    );
+}
+
+#[test]
+fn parse_incorrect_dollar_quoted_string() {
+    let sql = "SELECT $x$hello$$";
+    assert!(pg().parse_sql_statements(sql).is_err());
+
+    let sql = "SELECT $hello$$";
+    assert!(pg().parse_sql_statements(sql).is_err());
+
+    let sql = "SELECT $$$";
+    assert!(pg().parse_sql_statements(sql).is_err());
+}