chore(docs): refine docs (#1326)

Author: emilsivervik

src/parser/mod.rs

@@ -71,11 +71,11 @@ mod recursion {
     use super::ParserError;
 
     /// Tracks remaining recursion depth. This value is decremented on
-    /// each call to `try_decrease()`, when it reaches 0 an error will
+    /// each call to [`RecursionCounter::try_decrease()`], when it reaches 0 an error will
     /// be returned.
     ///
-    /// Note: Uses an Rc and Cell in order to satisfy the Rust
-    /// borrow checker so the automatic DepthGuard decrement a
+    /// Note: Uses an [`std::rc::Rc`] and [`std::cell::Cell`] in order to satisfy the Rust
+    /// borrow checker so the automatic [`DepthGuard`] decrement a
     /// reference to the counter.
     pub(crate) struct RecursionCounter {
         remaining_depth: Rc<Cell<usize>>,
@@ -92,7 +92,7 @@ mod recursion {
 
         /// Decreases the remaining depth by 1.
         ///
-        /// Returns `Err` if the remaining depth falls to 0.
+        /// Returns [`Err`] if the remaining depth falls to 0.
         ///
         /// Returns a [`DepthGuard`] which will adds 1 to the
         /// remaining depth upon drop;
@@ -131,7 +131,7 @@ mod recursion {
     /// Implementation [`RecursionCounter`] if std is NOT available (and does not
     /// guard against stack overflow).
     ///
-    /// Has the same API as the std RecursionCounter implementation
+    /// Has the same API as the std [`RecursionCounter`] implementation
     /// but does not actually limit stack depth.
     pub(crate) struct RecursionCounter {}
 
@@ -270,17 +270,17 @@ enum ParserState {
 
 pub struct Parser<'a> {
     tokens: Vec<TokenWithLocation>,
-    /// The index of the first unprocessed token in `self.tokens`
+    /// The index of the first unprocessed token in [`Parser::tokens`].
     index: usize,
     /// The current state of the parser.
     state: ParserState,
-    /// The current dialect to use
+    /// The current dialect to use.
     dialect: &'a dyn Dialect,
     /// Additional options that allow you to mix & match behavior
     /// otherwise constrained to certain dialects (e.g. trailing
-    /// commas) and/or format of parse (e.g. unescaping)
+    /// commas) and/or format of parse (e.g. unescaping).
     options: ParserOptions,
-    /// ensure the stack does not overflow by limiting recursion depth
+    /// Ensure the stack does not overflow by limiting recursion depth.
     recursion_counter: RecursionCounter,
 }
 
@@ -313,7 +313,6 @@ impl<'a> Parser<'a> {
 
     /// Specify the maximum recursion limit while parsing.
     ///
-    ///
     /// [`Parser`] prevents stack overflows by returning
     /// [`ParserError::RecursionLimitExceeded`] if the parser exceeds
     /// this depth while processing the query.
@@ -338,7 +337,6 @@ impl<'a> Parser<'a> {
 
     /// Specify additional parser options
     ///
-    ///
     /// [`Parser`] supports additional options ([`ParserOptions`])
     /// that allow you to mix & match behavior otherwise constrained
     /// to certain dialects (e.g. trailing commas).
@@ -824,7 +822,7 @@ impl<'a> Parser<'a> {
         })
     }
 
-    /// Parse a new expression including wildcard & qualified wildcard
+    /// Parse a new expression including wildcard & qualified wildcard.
     pub fn parse_wildcard_expr(&mut self) -> Result<Expr, ParserError> {
         let index = self.index;
 
@@ -867,13 +865,13 @@ impl<'a> Parser<'a> {
         self.parse_expr()
     }
 
-    /// Parse a new expression
+    /// Parse a new expression.
     pub fn parse_expr(&mut self) -> Result<Expr, ParserError> {
         let _guard = self.recursion_counter.try_decrease()?;
         self.parse_subexpr(0)
     }
 
-    /// Parse tokens until the precedence changes
+    /// Parse tokens until the precedence changes.
     pub fn parse_subexpr(&mut self, precedence: u8) -> Result<Expr, ParserError> {
         debug!("parsing expr");
         let mut expr = self.parse_prefix()?;
@@ -908,8 +906,7 @@ impl<'a> Parser<'a> {
         Ok(expr)
     }
 
-    /// Get the precedence of the next token
-    /// With AND, OR, and XOR
+    /// Get the precedence of the next token, with AND, OR, and XOR.
     pub fn get_next_interval_precedence(&self) -> Result<u8, ParserError> {
         let token = self.peek_token();
 
@@ -944,7 +941,7 @@ impl<'a> Parser<'a> {
         Ok(Statement::ReleaseSavepoint { name })
     }
 
-    /// Parse an expression prefix
+    /// Parse an expression prefix.
     pub fn parse_prefix(&mut self) -> Result<Expr, ParserError> {
         // allow the dialect to override prefix parsing
         if let Some(prefix) = self.dialect.parse_prefix(self) {
@@ -1456,8 +1453,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// parse a group by expr. a group by expr can be one of group sets, roll up, cube, or simple
-    /// expr.
+    /// Parse a group by expr. Group by expr can be one of group sets, roll up, cube, or simple expr.
     fn parse_group_by_expr(&mut self) -> Result<Expr, ParserError> {
         if self.dialect.supports_group_by_expr() {
             if self.parse_keywords(&[Keyword::GROUPING, Keyword::SETS]) {
@@ -1484,7 +1480,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// parse a tuple with `(` and `)`.
+    /// Parse a tuple with `(` and `)`.
     /// If `lift_singleton` is true, then a singleton tuple is lifted to a tuple of length 1, otherwise it will fail.
     /// If `allow_empty` is true, then an empty tuple is allowed.
     fn parse_tuple(
@@ -1953,13 +1949,11 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// Parses fulltext expressions [(1)]
+    /// Parses fulltext expressions [`sqlparser::ast::Expr::MatchAgainst`]
     ///
     /// # Errors
     /// This method will raise an error if the column list is empty or with invalid identifiers,
     /// the match expression is not a literal string, or if the search modifier is not valid.
-    ///
-    /// [(1)]: Expr::MatchAgainst
     pub fn parse_match_against(&mut self) -> Result<Expr, ParserError> {
         let columns = self.parse_parenthesized_column_list(Mandatory, false)?;
 
@@ -2004,17 +1998,19 @@ impl<'a> Parser<'a> {
         })
     }
 
-    /// Parse an INTERVAL expression.
+    /// Parse an `INTERVAL` expression.
     ///
     /// Some syntactically valid intervals:
     ///
-    ///   1. `INTERVAL '1' DAY`
-    ///   2. `INTERVAL '1-1' YEAR TO MONTH`
-    ///   3. `INTERVAL '1' SECOND`
-    ///   4. `INTERVAL '1:1:1.1' HOUR (5) TO SECOND (5)`
-    ///   5. `INTERVAL '1.1' SECOND (2, 2)`
-    ///   6. `INTERVAL '1:1' HOUR (5) TO MINUTE (5)`
-    ///   7. (MySql and BigQuey only):`INTERVAL 1 DAY`
+    /// ```sql
+    ///   1. INTERVAL '1' DAY
+    ///   2. INTERVAL '1-1' YEAR TO MONTH
+    ///   3. INTERVAL '1' SECOND
+    ///   4. INTERVAL '1:1:1.1' HOUR (5) TO SECOND (5)
+    ///   5. INTERVAL '1.1' SECOND (2, 2)
+    ///   6. INTERVAL '1:1' HOUR (5) TO MINUTE (5)
+    ///   7. (MySql & BigQuey only): INTERVAL 1 DAY
+    /// ```
     ///
     /// Note that we do not currently attempt to parse the quoted value.
     pub fn parse_interval(&mut self) -> Result<Expr, ParserError> {
@@ -2210,15 +2206,15 @@ impl<'a> Parser<'a> {
         ))
     }
 
-    /// Parse a field definition in a struct [1] or tuple [2].
+    /// Parse a field definition in a [struct] or [tuple].
     /// Syntax:
     ///
     /// ```sql
     /// [field_name] field_type
     /// ```
     ///
-    /// [1]: https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types#declaring_a_struct_type
-    /// [2]: https://clickhouse.com/docs/en/sql-reference/data-types/tuple
+    /// [struct]: https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types#declaring_a_struct_type
+    /// [tuple]: https://clickhouse.com/docs/en/sql-reference/data-types/tuple
     fn parse_struct_field_def(
         &mut self,
     ) -> Result<(StructField, MatchedTrailingBracket), ParserError> {
@@ -2272,15 +2268,15 @@ impl<'a> Parser<'a> {
         Ok(fields)
     }
 
-    /// DuckDB specific: Parse a duckdb dictionary [1]
+    /// DuckDB specific: Parse a duckdb [dictionary]
     ///
     /// Syntax:
     ///
     /// ```sql
     /// {'field_name': expr1[, ... ]}
     /// ```
     ///
-    /// [1]: https://duckdb.org/docs/sql/data_types/struct#creating-structs
+    /// [dictionary]: https://duckdb.org/docs/sql/data_types/struct#creating-structs
     fn parse_duckdb_struct_literal(&mut self) -> Result<Expr, ParserError> {
         self.expect_token(&Token::LBrace)?;
 
@@ -2291,13 +2287,15 @@ impl<'a> Parser<'a> {
         Ok(Expr::Dictionary(fields))
     }
 
-    /// Parse a field for a duckdb dictionary [1]
+    /// Parse a field for a duckdb [dictionary]
+    ///
     /// Syntax
+    ///
     /// ```sql
     /// 'name': expr
     /// ```
     ///
-    /// [1]: https://duckdb.org/docs/sql/data_types/struct#creating-structs
+    /// [dictionary]: https://duckdb.org/docs/sql/data_types/struct#creating-structs
     fn parse_duckdb_dictionary_field(&mut self) -> Result<DictionaryField, ParserError> {
         let key = self.parse_identifier(false)?;
 
@@ -2311,13 +2309,15 @@ impl<'a> Parser<'a> {
         })
     }
 
-    /// Parse clickhouse map [1]
+    /// Parse clickhouse [map]
+    ///
     /// Syntax
+    ///
     /// ```sql
     /// Map(key_data_type, value_data_type)
     /// ```
     ///
-    /// [1]: https://clickhouse.com/docs/en/sql-reference/data-types/map
+    /// [map]: https://clickhouse.com/docs/en/sql-reference/data-types/map
     fn parse_click_house_map_def(&mut self) -> Result<(DataType, DataType), ParserError> {
         self.expect_keyword(Keyword::MAP)?;
         self.expect_token(&Token::LParen)?;
@@ -2329,13 +2329,15 @@ impl<'a> Parser<'a> {
         Ok((key_data_type, value_data_type))
     }
 
-    /// Parse clickhouse tuple [1]
+    /// Parse clickhouse [tuple]
+    ///
     /// Syntax
+    ///
     /// ```sql
     /// Tuple([field_name] field_type, ...)
     /// ```
     ///
-    /// [1]: https://clickhouse.com/docs/en/sql-reference/data-types/tuple
+    /// [tuple]: https://clickhouse.com/docs/en/sql-reference/data-types/tuple
     fn parse_click_house_tuple_def(&mut self) -> Result<Vec<StructField>, ParserError> {
         self.expect_keyword(Keyword::TUPLE)?;
         self.expect_token(&Token::LParen)?;
@@ -2649,7 +2651,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// parse the ESCAPE CHAR portion of LIKE, ILIKE, and SIMILAR TO
+    /// Parse the `ESCAPE CHAR` portion of `LIKE`, `ILIKE`, and `SIMILAR TO`
     pub fn parse_escape_char(&mut self) -> Result<Option<String>, ParserError> {
         if self.parse_keyword(Keyword::ESCAPE) {
             Ok(Some(self.parse_literal_string()?))
@@ -2836,7 +2838,7 @@ impl<'a> Parser<'a> {
         })
     }
 
-    /// Parses the parens following the `[ NOT ] IN` operator
+    /// Parses the parens following the `[ NOT ] IN` operator.
     pub fn parse_in(&mut self, expr: Expr, negated: bool) -> Result<Expr, ParserError> {
         // BigQuery allows `IN UNNEST(array_expression)`
         // https://cloud.google.com/bigquery/docs/reference/standard-sql/operators#in_operators
@@ -2873,7 +2875,7 @@ impl<'a> Parser<'a> {
         Ok(in_op)
     }
 
-    /// Parses `BETWEEN <low> AND <high>`, assuming the `BETWEEN` keyword was already consumed
+    /// Parses `BETWEEN <low> AND <high>`, assuming the `BETWEEN` keyword was already consumed.
     pub fn parse_between(&mut self, expr: Expr, negated: bool) -> Result<Expr, ParserError> {
         // Stop parsing subexpressions for <low> and <high> on tokens with
         // precedence lower than that of `BETWEEN`, such as `AND`, `IS`, etc.
@@ -2888,7 +2890,7 @@ impl<'a> Parser<'a> {
         })
     }
 
-    /// Parse a postgresql casting style which is in the form of `expr::datatype`
+    /// Parse a postgresql casting style which is in the form of `expr::datatype`.
     pub fn parse_pg_cast(&mut self, expr: Expr) -> Result<Expr, ParserError> {
         Ok(Expr::Cast {
             kind: CastKind::DoubleColon,
@@ -2898,7 +2900,7 @@ impl<'a> Parser<'a> {
         })
     }
 
-    // use https://www.postgresql.org/docs/7.0/operators.htm#AEN2026 as a reference
+    // Use https://www.postgresql.org/docs/7.0/operators.htm#AEN2026 as a reference
     // higher number = higher precedence
     //
     // NOTE: The pg documentation is incomplete, e.g. the AT TIME ZONE operator
@@ -3217,7 +3219,7 @@ impl<'a> Parser<'a> {
 
     /// If the current token is one of the given `keywords`, consume the token
     /// and return the keyword that matches. Otherwise, no tokens are consumed
-    /// and returns `None`.
+    /// and returns [`None`].
     #[must_use]
     pub fn parse_one_of_keywords(&mut self, keywords: &[Keyword]) -> Option<Keyword> {
         match self.peek_token().token {
@@ -3393,8 +3395,7 @@ impl<'a> Parser<'a> {
         self.parse_comma_separated(f)
     }
 
-    /// Run a parser method `f`, reverting back to the current position
-    /// if unsuccessful.
+    /// Run a parser method `f`, reverting back to the current position if unsuccessful.
     #[must_use]
     fn maybe_parse<T, F>(&mut self, mut f: F) -> Option<T>
     where
@@ -3409,8 +3410,8 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// Parse either `ALL`, `DISTINCT` or `DISTINCT ON (...)`. Returns `None` if `ALL` is parsed
-    /// and results in a `ParserError` if both `ALL` and `DISTINCT` are found.
+    /// Parse either `ALL`, `DISTINCT` or `DISTINCT ON (...)`. Returns [`None`] if `ALL` is parsed
+    /// and results in a [`ParserError`] if both `ALL` and `DISTINCT` are found.
     pub fn parse_all_or_distinct(&mut self) -> Result<Option<Distinct>, ParserError> {
         let loc = self.peek_token().location;
         let all = self.parse_keyword(Keyword::ALL);