Handle break and return better.

src/result.rs

@@ -62,8 +62,8 @@ pub enum EvalAltResult {
     ErrorArithmetic(String, Position),
     /// Run-time error encountered. Wrapped value is the error message.
     ErrorRuntime(String, Position),
-    /// Internal use: Breaking out of loops.
-    LoopBreak,
+    /// Breaking out of loops - not an error if within a loop.
+    ErrorLoopBreak(Position),
     /// Not an error: Value returned from a script via the `return` keyword.
     /// Wrapped value is the result value.
     Return(Dynamic, Position),
@@ -106,7 +106,7 @@ impl EvalAltResult {
             Self::ErrorDotExpr(_, _) => "Malformed dot expression",
             Self::ErrorArithmetic(_, _) => "Arithmetic error",
             Self::ErrorRuntime(_, _) => "Runtime error",
-            Self::LoopBreak => "[Not Error] Breaks out of loop",
+            Self::ErrorLoopBreak(_) => "Break statement not inside a loop",
             Self::Return(_, _) => "[Not Error] Function returns value",
         }
     }
@@ -134,7 +134,7 @@ impl fmt::Display for EvalAltResult {
             Self::ErrorRuntime(s, pos) => {
                 write!(f, "{} ({})", if s.is_empty() { desc } else { s }, pos)
             }
-            Self::LoopBreak => write!(f, "{}", desc),
+            Self::ErrorLoopBreak(pos) => write!(f, "{} ({})", desc, pos),
             Self::Return(_, pos) => write!(f, "{} ({})", desc, pos),
             #[cfg(not(feature = "no_stdlib"))]
             Self::ErrorReadingScriptFile(path, err) => {
@@ -211,7 +211,6 @@ impl EvalAltResult {
         match self {
             #[cfg(not(feature = "no_stdlib"))]
             Self::ErrorReadingScriptFile(_, _) => Position::none(),
-            Self::LoopBreak => Position::none(),
 
             Self::ErrorParsing(err) => err.position(),
 
@@ -232,6 +231,7 @@ impl EvalAltResult {
             | Self::ErrorDotExpr(_, pos)
             | Self::ErrorArithmetic(_, pos)
             | Self::ErrorRuntime(_, pos)
+            | Self::ErrorLoopBreak(pos)
             | Self::Return(_, pos) => *pos,
         }
     }
@@ -240,7 +240,6 @@ impl EvalAltResult {
         match self {
             #[cfg(not(feature = "no_stdlib"))]
             Self::ErrorReadingScriptFile(_, _) => (),
-            Self::LoopBreak => (),
 
             Self::ErrorParsing(ParseError(_, ref mut pos))
             | Self::ErrorFunctionNotFound(_, ref mut pos)
@@ -260,6 +259,7 @@ impl EvalAltResult {
             | Self::ErrorDotExpr(_, ref mut pos)
             | Self::ErrorArithmetic(_, ref mut pos)
             | Self::ErrorRuntime(_, ref mut pos)
+            | Self::ErrorLoopBreak(ref mut pos)
             | Self::Return(_, ref mut pos) => *pos = new_position,
         }
     }