scarpet v1.2

src/main/java/carpet/script/exception/ExpressionException.java

@@ -0,0 +1,60 @@
+package carpet.script.exception;
+
+import carpet.script.Expression;
+import carpet.script.Fluff;
+import carpet.script.Tokenizer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static carpet.script.ExpressionInspector.Expression_getExpressionSnippet;
+import static carpet.script.ExpressionInspector.Expression_getName;
+
+/* The expression evaluators exception class. */
+public class ExpressionException extends RuntimeException
+{
+    public ExpressionException(String message)
+    {
+        super(message);
+    }
+
+    private static Fluff.TriFunction<Expression, Tokenizer.Token, String, List<String>> errorMaker = (expr, token, errmessage) ->
+    {
+
+        List<String> snippet = Expression_getExpressionSnippet(token, expr);
+        List<String> errMsg = new ArrayList<>(snippet);
+        if (snippet.size() != 1)
+        {
+            errmessage+= " at line "+(token.lineno+1)+", pos "+(token.linepos+1);
+        }
+        else
+        {
+            errmessage += " at pos "+(token.pos+1);
+        }
+        if (Expression_getName(expr) != null)
+        {
+            errmessage += " ("+Expression_getName(expr)+")";
+        }
+        errMsg.add(errmessage);
+        return errMsg;
+    };
+    public static Fluff.TriFunction<Expression, Tokenizer.Token, String, List<String>> errorSnooper = null;
+
+    static String makeMessage(Expression e, Tokenizer.Token t, String message) throws ExpressionException
+    {
+        if (errorSnooper != null)
+        {
+            List<String> alternative = errorSnooper.apply(e, t, message);
+            if (alternative!= null)
+            {
+                return String.join("\n", alternative);
+            }
+        }
+        return String.join("\n", errorMaker.apply(e, t, message));
+    }
+
+    public ExpressionException(Expression e, Tokenizer.Token t, String message)
+    {
+        super(makeMessage(e, t, message));
+    }
+}