add KissError.hx

src/kiss/KissError.hx

@@ -0,0 +1,70 @@
+package kiss;
+
+import kiss.Reader;
+import kiss.List;
+
+using kiss.Stream;
+using kiss.Reader;
+
+enum ErrorType {
+    CantCompile;
+    CompileWarning;
+    AssertionFail;
+}
+
+// Internal Kiss errors
+class KissError {
+    var exps:List<ReaderExp>;
+    var message:String;
+
+    function new(exps:Array<ReaderExp>, message:String) {
+        this.exps = exps;
+        this.message = message;
+    }
+
+    public static function fromExp(exp:ReaderExp, message:String) {
+        return new KissError([exp], message);
+    }
+
+    public static function fromExpStr(pos:Position, expStr:String, message:String) {
+        switch (Reader.read(Stream.fromString(expStr), Kiss.defaultKissState())) {
+            case Some(exp):
+                return fromExp({pos: pos, def: exp.def}, message);
+            default:
+                throw 'bad'; // TODO better message
+        }
+    }
+
+    public static function fromArgs(exps:Array<ReaderExp>, message:String) {
+        return new KissError(exps, message);
+    }
+
+    public function toString(type = CantCompile) {
+        var posPrefix = switch (exps.length) {
+            case 1:
+                exps[0].pos.toPrint();
+            default:
+                var firstPos = exps[0].pos.toPrint();
+                var lastPos = exps[-1].pos.toPrint();
+                var justLineAndColumnIdx = lastPos.indexOf(":") + 1;
+                firstPos + '-' + lastPos.substr(justLineAndColumnIdx);
+        }
+
+        var typePrefix = switch (type) {
+            case CantCompile:
+                "Kiss compilation failed";
+            case CompileWarning:
+                "Kiss compilation warning";
+            case AssertionFail:
+                "Assertion failed";
+        };
+
+        return '$posPrefix: $typePrefix: $message'
+            + "\nFrom:"
+            + [for (exp in exps) exp.def.toString()].toString();
+    }
+
+    public static function warnFromExp(exp:ReaderExp, message:String) {
+        Prelude.print(new KissError([exp], message).toString(CompileWarning));
+    }
+}