Better convert LexError to ParseError.

src/error.rs

@@ -22,8 +22,8 @@ pub enum LexError {
     MalformedChar(String),
     /// An identifier is in an invalid format.
     MalformedIdentifier(String),
-    /// Bad keyword encountered when tokenizing the script text.
-    ImproperKeyword(String),
+    /// Bad symbol encountered when tokenizing the script text.
+    ImproperSymbol(String),
 }
 
 impl Error for LexError {}
@@ -42,11 +42,18 @@ impl fmt::Display for LexError {
                 "Length of string literal exceeds the maximum limit ({})",
                 max
             ),
-            Self::ImproperKeyword(s) => write!(f, "{}", s),
+            Self::ImproperSymbol(s) => write!(f, "{}", s),
         }
     }
 }
 
+impl LexError {
+    /// Convert a `LexError` into a `ParseError`.
+    pub fn into_err(&self, pos: Position) -> ParseError {
+        ParseError(Box::new(self.into()), pos)
+    }
+}
+
 /// Type of error encountered when parsing a script.
 ///
 /// Some errors never appear when certain features are turned on.
@@ -217,6 +224,17 @@ impl fmt::Display for ParseErrorType {
     }
 }
 
+impl From<&LexError> for ParseErrorType {
+    fn from(err: &LexError) -> Self {
+        match err {
+            LexError::StringTooLong(max) => {
+                Self::LiteralTooLarge("Length of string literal".to_string(), *max)
+            }
+            _ => Self::BadInput(err.to_string()),
+        }
+    }
+}
+
 /// Error when parsing a script.
 #[derive(Debug, Eq, PartialEq, Clone, Hash)]
 pub struct ParseError(pub Box<ParseErrorType>, pub Position);