Move Value::Interval to Expr::Interval (#609)

* refactor(value): convert Value::Interval to Expr::Interval

* test(sqlparser_common): modify test case

* refactor(parser): rename func parse_interval

* refactor(tests) rename parse_interval test func

src/ast/mod.rs

@@ -410,6 +410,25 @@ pub enum Expr {
     ArrayIndex { obj: Box<Expr>, indexes: Vec<Expr> },
     /// An array expression e.g. `ARRAY[1, 2]`
     Array(Array),
+    /// INTERVAL literals, roughly in the following format:
+    /// `INTERVAL '<value>' [ <leading_field> [ (<leading_precision>) ] ]
+    /// [ TO <last_field> [ (<fractional_seconds_precision>) ] ]`,
+    /// e.g. `INTERVAL '123:45.67' MINUTE(3) TO SECOND(2)`.
+    ///
+    /// The parser does not validate the `<value>`, nor does it ensure
+    /// that the `<leading_field>` units >= the units in `<last_field>`,
+    /// so the user will have to reject intervals like `HOUR TO YEAR`.
+    Interval {
+        value: Box<Expr>,
+        leading_field: Option<DateTimeField>,
+        leading_precision: Option<u64>,
+        last_field: Option<DateTimeField>,
+        /// The seconds precision can be specified in SQL source as
+        /// `INTERVAL '__' SECOND(_, x)` (in which case the `leading_field`
+        /// will be `Second` and the `last_field` will be `None`),
+        /// or as `__ TO SECOND(x)`.
+        fractional_seconds_precision: Option<u64>,
+    },
 }
 
 impl fmt::Display for Expr {
@@ -722,6 +741,44 @@ impl fmt::Display for Expr {
             } => {
                 write!(f, "{} AT TIME ZONE '{}'", timestamp, time_zone)
             }
+            Expr::Interval {
+                value,
+                leading_field: Some(DateTimeField::Second),
+                leading_precision: Some(leading_precision),
+                last_field,
+                fractional_seconds_precision: Some(fractional_seconds_precision),
+            } => {
+                // When the leading field is SECOND, the parser guarantees that
+                // the last field is None.
+                assert!(last_field.is_none());
+                write!(
+                    f,
+                    "INTERVAL {} SECOND ({}, {})",
+                    value, leading_precision, fractional_seconds_precision
+                )
+            }
+            Expr::Interval {
+                value,
+                leading_field,
+                leading_precision,
+                last_field,
+                fractional_seconds_precision,
+            } => {
+                write!(f, "INTERVAL {}", value)?;
+                if let Some(leading_field) = leading_field {
+                    write!(f, " {}", leading_field)?;
+                }
+                if let Some(leading_precision) = leading_precision {
+                    write!(f, " ({})", leading_precision)?;
+                }
+                if let Some(last_field) = last_field {
+                    write!(f, " TO {}", last_field)?;
+                }
+                if let Some(fractional_seconds_precision) = fractional_seconds_precision {
+                    write!(f, " ({})", fractional_seconds_precision)?;
+                }
+                Ok(())
+            }
         }
     }
 }

src/ast/value.rs

@@ -21,8 +21,6 @@ use bigdecimal::BigDecimal;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-use super::Expr;
-
 /// Primitive SQL values such as number and string
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -45,25 +43,6 @@ pub enum Value {
     DoubleQuotedString(String),
     /// Boolean value true or false
     Boolean(bool),
-    /// INTERVAL literals, roughly in the following format:
-    /// `INTERVAL '<value>' [ <leading_field> [ (<leading_precision>) ] ]
-    /// [ TO <last_field> [ (<fractional_seconds_precision>) ] ]`,
-    /// e.g. `INTERVAL '123:45.67' MINUTE(3) TO SECOND(2)`.
-    ///
-    /// The parser does not validate the `<value>`, nor does it ensure
-    /// that the `<leading_field>` units >= the units in `<last_field>`,
-    /// so the user will have to reject intervals like `HOUR TO YEAR`.
-    Interval {
-        value: Box<Expr>,
-        leading_field: Option<DateTimeField>,
-        leading_precision: Option<u64>,
-        last_field: Option<DateTimeField>,
-        /// The seconds precision can be specified in SQL source as
-        /// `INTERVAL '__' SECOND(_, x)` (in which case the `leading_field`
-        /// will be `Second` and the `last_field` will be `None`),
-        /// or as `__ TO SECOND(x)`.
-        fractional_seconds_precision: Option<u64>,
-    },
     /// `NULL` value
     Null,
     /// `?` or `$` Prepared statement arg placeholder
@@ -80,44 +59,6 @@ impl fmt::Display for Value {
             Value::NationalStringLiteral(v) => write!(f, "N'{}'", v),
             Value::HexStringLiteral(v) => write!(f, "X'{}'", v),
             Value::Boolean(v) => write!(f, "{}", v),
-            Value::Interval {
-                value,
-                leading_field: Some(DateTimeField::Second),
-                leading_precision: Some(leading_precision),
-                last_field,
-                fractional_seconds_precision: Some(fractional_seconds_precision),
-            } => {
-                // When the leading field is SECOND, the parser guarantees that
-                // the last field is None.
-                assert!(last_field.is_none());
-                write!(
-                    f,
-                    "INTERVAL {} SECOND ({}, {})",
-                    value, leading_precision, fractional_seconds_precision
-                )
-            }
-            Value::Interval {
-                value,
-                leading_field,
-                leading_precision,
-                last_field,
-                fractional_seconds_precision,
-            } => {
-                write!(f, "INTERVAL {}", value)?;
-                if let Some(leading_field) = leading_field {
-                    write!(f, " {}", leading_field)?;
-                }
-                if let Some(leading_precision) = leading_precision {
-                    write!(f, " ({})", leading_precision)?;
-                }
-                if let Some(last_field) = last_field {
-                    write!(f, " TO {}", last_field)?;
-                }
-                if let Some(fractional_seconds_precision) = fractional_seconds_precision {
-                    write!(f, " ({})", fractional_seconds_precision)?;
-                }
-                Ok(())
-            }
             Value::Null => write!(f, "NULL"),
             Value::Placeholder(v) => write!(f, "{}", v),
         }

src/parser.rs

@@ -402,7 +402,7 @@ impl<'a> Parser<'a> {
         // expression that should parse as the column name "date".
         return_ok_if_some!(self.maybe_parse(|parser| {
             match parser.parse_data_type()? {
-                DataType::Interval => parser.parse_literal_interval(),
+                DataType::Interval => parser.parse_interval(),
                 // PostgreSQL allows almost any identifier to be used as custom data type name,
                 // and we support that in `parse_data_type()`. But unlike Postgres we don't
                 // have a list of globally reserved keywords (since they vary across dialects),
@@ -455,7 +455,7 @@ impl<'a> Parser<'a> {
                 Keyword::SUBSTRING => self.parse_substring_expr(),
                 Keyword::OVERLAY => self.parse_overlay_expr(),
                 Keyword::TRIM => self.parse_trim_expr(),
-                Keyword::INTERVAL => self.parse_literal_interval(),
+                Keyword::INTERVAL => self.parse_interval(),
                 Keyword::LISTAGG => self.parse_listagg_expr(),
                 // Treat ARRAY[1,2,3] as an array [1,2,3], otherwise try as subquery or a function call
                 Keyword::ARRAY if self.peek_token() == Token::LBracket => {
@@ -1096,7 +1096,7 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// Parse an INTERVAL literal.
+    /// Parse an INTERVAL expression.
     ///
     /// Some syntactically valid intervals:
     ///
@@ -1109,7 +1109,7 @@ impl<'a> Parser<'a> {
     ///   7. (MySql and BigQuey only):`INTERVAL 1 DAY`
     ///
     /// Note that we do not currently attempt to parse the quoted value.
-    pub fn parse_literal_interval(&mut self) -> Result<Expr, ParserError> {
+    pub fn parse_interval(&mut self) -> Result<Expr, ParserError> {
         // The SQL standard allows an optional sign before the value string, but
         // it is not clear if any implementations support that syntax, so we
         // don't currently try to parse it. (The sign can instead be included
@@ -1183,13 +1183,13 @@ impl<'a> Parser<'a> {
                 }
             };
 
-        Ok(Expr::Value(Value::Interval {
+        Ok(Expr::Interval {
             value: Box::new(value),
             leading_field,
             leading_precision,
             last_field,
             fractional_seconds_precision: fsec_precision,
-        }))
+        })
     }
 
     /// Parse an operator following an expression
@@ -3178,7 +3178,7 @@ impl<'a> Parser<'a> {
                 }
                 // Interval types can be followed by a complicated interval
                 // qualifier that we don't currently support. See
-                // parse_interval_literal for a taste.
+                // parse_interval for a taste.
                 Keyword::INTERVAL => Ok(DataType::Interval),
                 Keyword::REGCLASS => Ok(DataType::Regclass),
                 Keyword::STRING => Ok(DataType::String),

tests/sqlparser_common.rs

@@ -2930,24 +2930,24 @@ fn parse_literal_timestamp_with_time_zone() {
 }
 
 #[test]
-fn parse_literal_interval() {
+fn parse_interval() {
     let sql = "SELECT INTERVAL '1-1' YEAR TO MONTH";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::Value(Value::SingleQuotedString(String::from("1-1")))),
             leading_field: Some(DateTimeField::Year),
             leading_precision: None,
             last_field: Some(DateTimeField::Month),
             fractional_seconds_precision: None,
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );
 
     let sql = "SELECT INTERVAL '01:01.01' MINUTE (5) TO SECOND (5)";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::Value(Value::SingleQuotedString(String::from(
                 "01:01.01"
             )))),
@@ -2955,53 +2955,53 @@ fn parse_literal_interval() {
             leading_precision: Some(5),
             last_field: Some(DateTimeField::Second),
             fractional_seconds_precision: Some(5),
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );
 
     let sql = "SELECT INTERVAL '1' SECOND (5, 4)";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::Value(Value::SingleQuotedString(String::from("1")))),
             leading_field: Some(DateTimeField::Second),
             leading_precision: Some(5),
             last_field: None,
             fractional_seconds_precision: Some(4),
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );
 
     let sql = "SELECT INTERVAL '10' HOUR";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::Value(Value::SingleQuotedString(String::from("10")))),
             leading_field: Some(DateTimeField::Hour),
             leading_precision: None,
             last_field: None,
             fractional_seconds_precision: None,
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );
 
     let sql = "SELECT INTERVAL 5 DAY";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::Value(number("5"))),
             leading_field: Some(DateTimeField::Day),
             leading_precision: None,
             last_field: None,
             fractional_seconds_precision: None,
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );
 
     let sql = "SELECT INTERVAL 1 + 1 DAY";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::BinaryOp {
                 left: Box::new(Expr::Value(number("1"))),
                 op: BinaryOperator::Plus,
@@ -3011,27 +3011,27 @@ fn parse_literal_interval() {
             leading_precision: None,
             last_field: None,
             fractional_seconds_precision: None,
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );
 
     let sql = "SELECT INTERVAL '10' HOUR (1)";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::Value(Value::SingleQuotedString(String::from("10")))),
             leading_field: Some(DateTimeField::Hour),
             leading_precision: Some(1),
             last_field: None,
             fractional_seconds_precision: None,
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );
 
     let sql = "SELECT INTERVAL '1 DAY'";
     let select = verified_only_select(sql);
     assert_eq!(
-        &Expr::Value(Value::Interval {
+        &Expr::Interval {
             value: Box::new(Expr::Value(Value::SingleQuotedString(String::from(
                 "1 DAY"
             )))),
@@ -3039,7 +3039,7 @@ fn parse_literal_interval() {
             leading_precision: None,
             last_field: None,
             fractional_seconds_precision: None,
-        }),
+        },
         expr_from_projection(only(&select.projection)),
     );