Simplify, clippy

src/ast/mod.rs

@@ -209,8 +209,8 @@ pub enum Expr {
     /// SUBSTRING(<expr> [FROM <expr>] [FOR <expr>])
     Substring {
         expr: Box<Expr>,
-        substring_from: Option<SubstringFrom>,
-        substring_for: Option<SubstringFor>,
+        substring_from: Option<Box<Expr>>,
+        substring_for: Option<Box<Expr>>,
     },
     /// `expr COLLATE collation`
     Collate {
@@ -347,10 +347,10 @@ impl fmt::Display for Expr {
             } => {
                 write!(f, "SUBSTRING({}", expr)?;
                 if let Some(from_part) = substring_from {
-                    write!(f, " {}", from_part)?;
+                    write!(f, " FROM {}", from_part)?;
                 }
                 if let Some(from_part) = substring_for {
-                    write!(f, " {}", from_part)?;
+                    write!(f, " FOR {}", from_part)?;
                 }
 
                 write!(f, ")")
@@ -460,39 +460,6 @@ impl fmt::Display for WindowFrameBound {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-/// FROM part of SUBSTRING(<expr> [FROM <expr>])
-pub enum SubstringFrom {
-    ///
-    FromExpr(Box<Expr>),
-}
-
-impl fmt::Display for SubstringFrom {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            SubstringFrom::FromExpr(expr) => {
-                write!(f, "FROM {}", expr)
-            }
-        }
-    }
-}
-
-/// FROM part of SUBSTRING(<expr> [TO <expr>])
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub enum SubstringFor {
-    ForExpr(Box<Expr>),
-}
-
-impl fmt::Display for SubstringFor {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            SubstringFor::ForExpr(expr) => {
-                write!(f, "FOR {}", expr)
-            }
-        }
-    }
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum AddDropSync {

src/parser.rs

@@ -623,8 +623,8 @@ impl<'a> Parser<'a> {
 
         Ok(Expr::Substring {
             expr: Box::new(expr),
-            substring_from: from_expr.map(|x| SubstringFrom::FromExpr(Box::new(x))),
-            substring_for: to_expr.map(|x| SubstringFor::ForExpr(Box::new(x))),
+            substring_from: from_expr.map(Box::new),
+            substring_for: to_expr.map(Box::new),
         })
     }
 

tests/sqlparser_regression.rs

@@ -26,7 +26,7 @@ macro_rules! tpch_tests {
         fn $name() {
             let dialect = GenericDialect {};
 
-            let res = Parser::parse_sql(&dialect, QUERIES[$value -1]);
+            let _res = Parser::parse_sql(&dialect, QUERIES[$value -1]);
         }
     )*
     }