Add THEN and ELSE as logical operators

Make the lexer know about the existence of the `THEN` and `ELSE` word as logical operators to tokenize them.
appsignal · Jul 26, 2023 · c98665d · c98665d
1 parent 3ea4f71
commit c98665d
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Showing 3 changed files with 25 additions and 3 deletions.
diff --git a/src/lexer.rs b/src/lexer.rs
@@ -315,6 +315,12 @@ impl SqlLexer {
                         s if s.eq_ignore_ascii_case("not") => {
                             Token::Operator(Operator::Logical(LogicalOperator::Not))
                         }
+                        s if s.eq_ignore_ascii_case("then") => {
+                            Token::Operator(Operator::Logical(LogicalOperator::Then))
+                        }
+                        s if s.eq_ignore_ascii_case("else") => {
+                            Token::Operator(Operator::Logical(LogicalOperator::Else))
+                        }
                         s if s.eq_ignore_ascii_case("like") => {
                             Token::Operator(Operator::Logical(LogicalOperator::Like))
                         }
@@ -626,7 +632,7 @@ mod tests {
 
     #[test]
     fn test_logical_operators_uppercase() {
-        let sql = "IN NOT LIKE ILIKE RLIKE GLOB MATCH REGEXP".to_string();
+        let sql = "IN NOT LIKE ILIKE RLIKE GLOB MATCH REGEXP THEN ELSE".to_string();
         let lexer = SqlLexer::new(sql);
 
         let expected = vec![
@@ -645,14 +651,18 @@ mod tests {
             Token::Operator(Operator::Logical(LogicalOperator::Match)),
             Token::Space,
             Token::Operator(Operator::Logical(LogicalOperator::Regexp)),
+            Token::Space,
+            Token::Operator(Operator::Logical(LogicalOperator::Then)),
+            Token::Space,
+            Token::Operator(Operator::Logical(LogicalOperator::Else)),
         ];
 
         assert_eq!(lexer.lex().tokens, expected);
     }
 
     #[test]
     fn test_logical_operators_lowercase() {
-        let sql = "in not like rlike glob match regexp".to_string();
+        let sql = "in not like rlike glob match regexp then else".to_string();
         let lexer = SqlLexer::new(sql);
 
         let expected = vec![
@@ -669,14 +679,18 @@ mod tests {
             Token::Operator(Operator::Logical(LogicalOperator::Match)),
             Token::Space,
             Token::Operator(Operator::Logical(LogicalOperator::Regexp)),
+            Token::Space,
+            Token::Operator(Operator::Logical(LogicalOperator::Then)),
+            Token::Space,
+            Token::Operator(Operator::Logical(LogicalOperator::Else)),
         ];
 
         assert_eq!(lexer.lex().tokens, expected);
     }
 
     #[test]
     fn test_logical_operators_mixedcase() {
-        let sql = "In Not Like Rlike Glob Match Regexp".to_string();
+        let sql = "In Not Like Rlike Glob Match Regexp tHen ElsE".to_string();
         let lexer = SqlLexer::new(sql);
 
         let expected = vec![
@@ -693,6 +707,10 @@ mod tests {
             Token::Operator(Operator::Logical(LogicalOperator::Match)),
             Token::Space,
             Token::Operator(Operator::Logical(LogicalOperator::Regexp)),
+            Token::Space,
+            Token::Operator(Operator::Logical(LogicalOperator::Then)),
+            Token::Space,
+            Token::Operator(Operator::Logical(LogicalOperator::Else)),
         ];
 
         assert_eq!(lexer.lex().tokens, expected);

diff --git a/src/lib.rs b/src/lib.rs
@@ -57,6 +57,8 @@ pub enum LogicalOperator {
     Glob,   // GLOB
     Match,  // MATCH
     Regexp, // REGEXP
+    Then,   // THEN
+    Else,   // ELSE
 }
 
 #[derive(Debug, PartialEq)]

diff --git a/src/writer.rs b/src/writer.rs
@@ -33,6 +33,8 @@ impl SqlWriter {
                 Token::Operator(Operator::Logical(LogicalOperator::Rlike)) => out.push_str("RLIKE"),
                 Token::Operator(Operator::Logical(LogicalOperator::Glob)) => out.push_str("GLOB"),
                 Token::Operator(Operator::Logical(LogicalOperator::Match)) => out.push_str("MATCH"),
+                Token::Operator(Operator::Logical(LogicalOperator::Then)) => out.push_str("THEN"),
+                Token::Operator(Operator::Logical(LogicalOperator::Else)) => out.push_str("ELSE"),
                 Token::Operator(Operator::Logical(LogicalOperator::Regexp)) => {
                     out.push_str("REGEXP")
                 }