fix: bare STATUS and SHOW STATUS commands now work (issue #470)

Three problems fixed:

1. Grammar: add standalone `statusStatement: STATUS ;` wired into
   `utilityStatement`, so `STATUS` parses outside of a SHOW context.

2. Visitor (ExitShowStatement): `SHOW STATUS` (without CATALOG) was
   silently dropped because the STATUS token was only checked inside
   the CATALOG branch. Added a new `ctx.STATUS() != nil` branch (after
   CATALOG so SHOW CATALOG STATUS is unaffected) that emits StatusStmt.

3. Visitor (ExitHelpStatement): removed dead `case "status"` — STATUS
   is a lexer keyword so it can never match IDENTIFIER, making this
   branch unreachable.

Both `STATUS;` and `SHOW STATUS;` now print connection status.
`SHOW CATALOG STATUS` is unaffected.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: ako

mdl/grammar/MDLParser.g4

@@ -3467,6 +3467,7 @@ limitOffsetClause
 utilityStatement
     : connectStatement
     | disconnectStatement
+    | statusStatement
     | updateStatement
     | checkStatement
     | buildStatement
@@ -3497,6 +3498,10 @@ disconnectStatement
     : DISCONNECT
     ;
 
+statusStatement
+    : STATUS
+    ;
+
 updateStatement
     : UPDATE
     | REFRESH CATALOG FULL? SOURCE_KW? FORCE? BACKGROUND?

mdl/grammar/parser/MDLParser.interp

@@ -28,6 +28,11 @@ func (b *Builder) ExitDisconnectStatement(ctx *parser.DisconnectStatementContext
 	b.statements = append(b.statements, &ast.DisconnectStmt{})
 }
 
+// ExitStatusStatement is called when exiting the statusStatement production (bare STATUS).
+func (b *Builder) ExitStatusStatement(ctx *parser.StatusStatementContext) {
+	b.statements = append(b.statements, &ast.StatusStmt{})
+}
+
 // ----------------------------------------------------------------------------
 // Module Statements
 // ----------------------------------------------------------------------------

mdl/grammar/parser/mdl_parser.go

@@ -40,3 +40,37 @@ func TestDisconnect(t *testing.T) {
 		t.Fatalf("Expected DisconnectStmt, got %T", prog.Statements[0])
 	}
 }
+
+func TestStatus_BareKeyword(t *testing.T) {
+	prog, errs := Build(`STATUS;`)
+	if len(errs) > 0 {
+		t.Fatalf("Parse errors for bare STATUS: %v", errs)
+	}
+	if _, ok := prog.Statements[0].(*ast.StatusStmt); !ok {
+		t.Fatalf("Expected StatusStmt, got %T", prog.Statements[0])
+	}
+}
+
+func TestStatus_ShowStatus(t *testing.T) {
+	prog, errs := Build(`SHOW STATUS;`)
+	if len(errs) > 0 {
+		t.Fatalf("Parse errors for SHOW STATUS: %v", errs)
+	}
+	if _, ok := prog.Statements[0].(*ast.StatusStmt); !ok {
+		t.Fatalf("Expected StatusStmt for SHOW STATUS, got %T", prog.Statements[0])
+	}
+}
+
+func TestStatus_ShowCatalogStatusUnaffected(t *testing.T) {
+	prog, errs := Build(`SHOW CATALOG STATUS;`)
+	if len(errs) > 0 {
+		t.Fatalf("Parse errors for SHOW CATALOG STATUS: %v", errs)
+	}
+	stmt, ok := prog.Statements[0].(*ast.ShowStmt)
+	if !ok {
+		t.Fatalf("Expected ShowStmt, got %T", prog.Statements[0])
+	}
+	if stmt.ObjectType != ast.ShowCatalogStatus {
+		t.Errorf("Expected ShowCatalogStatus, got %v", stmt.ObjectType)
+	}
+}

mdl/grammar/parser/mdlparser_base_listener.go

@@ -217,13 +217,15 @@ func (b *Builder) ExitShowStatement(ctx *parser.ShowStatementContext) {
 	} else if ctx.VERSION() != nil {
 		b.statements = append(b.statements, &ast.ShowStmt{ObjectType: ast.ShowVersion})
 	} else if ctx.CATALOG() != nil {
-		// Check for SHOW CATALOG STATUS
+		// SHOW CATALOG STATUS or SHOW CATALOG TABLES
 		if ctx.STATUS() != nil {
 			b.statements = append(b.statements, &ast.ShowStmt{ObjectType: ast.ShowCatalogStatus})
 		} else {
-			// SHOW CATALOG TABLES (or other catalog show commands)
 			b.statements = append(b.statements, &ast.ShowStmt{ObjectType: ast.ShowCatalogTables})
 		}
+	} else if ctx.STATUS() != nil {
+		// SHOW STATUS — print connection status (path, version, module count)
+		b.statements = append(b.statements, &ast.StatusStmt{})
 	} else if ctx.CALLERS() != nil {
 		// SHOW CALLERS OF Module.Microflow [TRANSITIVE]
 		if qn := ctx.QualifiedName(); qn != nil {
@@ -1033,8 +1035,6 @@ func (b *Builder) ExitHelpStatement(ctx *parser.HelpStatementContext) {
 			b.statements = append(b.statements, stmt)
 		case "exit", "quit":
 			b.statements = append(b.statements, &ast.ExitStmt{})
-		case "status":
-			b.statements = append(b.statements, &ast.StatusStmt{})
 		}
 	}
 }