Preparo para fórmulas que devuelven cadenas

.metadata

@@ -4,7 +4,7 @@
 # This file should be version controlled and should not be manually edited.
 
 version:
-  revision: "077b4a4ce10a07b82caa6897f0c626f9c0a3ac90"
+  revision: "05db9689081f091050f01aed79f04dce0c750154"
   channel: "stable"
 
 project_type: app
@@ -13,26 +13,11 @@ project_type: app
 migration:
   platforms:
     - platform: root
-      create_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
+      create_revision: 05db9689081f091050f01aed79f04dce0c750154
-      base_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
+      base_revision: 05db9689081f091050f01aed79f04dce0c750154
-    - platform: android
-      create_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-      base_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-    - platform: ios
-      create_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-      base_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-    - platform: linux
-      create_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-      base_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-    - platform: macos
-      create_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-      base_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
     - platform: web
-      create_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
+      create_revision: 05db9689081f091050f01aed79f04dce0c750154
-      base_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
+      base_revision: 05db9689081f091050f01aed79f04dce0c750154
-    - platform: windows
-      create_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
-      base_revision: 077b4a4ce10a07b82caa6897f0c626f9c0a3ac90
 
   # User provided section
 

lib/ai/formula_screen.dart

@@ -26,7 +26,7 @@ class D4rtEditingController extends TextEditingController {
   String? _lastError;
 
   String? get lastError => _lastError;
-  Number? _lastValue;
+  FormulaResult? _lastValue;
 
   D4rtEditingController({String? text}) : super(text: text);
 
@@ -36,8 +36,10 @@ class D4rtEditingController extends TextEditingController {
       _lastValue = FormulaEvaluator.evaluateExpression(text);
       _lastError = null;
       return true;
-    } catch (e) {
+    } catch (e, s) {
       _lastError = e.toString();
+      print( "validate: $text: $e" );
+      print( "stack: $s" );
       return false;
     }
   }
@@ -98,16 +100,25 @@ class _FormulaScreenState extends State<FormulaScreen> {
         if( controller.d4rtValue == null ){
           throw FormulaEvaluationException( "Field ${input.name} is invalid" );
         }
-        final value = controller.d4rtValue;
+        final value = controller.d4rtValue.value;
 
         // Convert input to base unit if needed
         // Always convert from dropdown unit to variable's base unit
-        inputValues[input.name] = widget.corpus.convert(
+        late final convertedValue;
+        if( value is Number ) {
+          convertedValue = widget.corpus.convert(
             value,
             _selectedUnits[input.name]!,
             input.unit,
           );
         }
+        else{
+          convertedValue = value;
+        }
+
+        inputValues[input.name] = convertedValue;
+
+      }
 
       final evaluator = FormulaEvaluator();
       final result = evaluator.evaluate(widget.formula, inputValues);

lib/formula_evaluator.dart

@@ -25,6 +25,20 @@ class MyMath{
   static Number myPow(Number b, Number e) => Math.pow(b,e) as Number;
 }
 
+class FormulaResult{
+  const FormulaResult();
+}
+
+class StringResult extends FormulaResult{
+  final String value;
+  const StringResult(this.value);
+}
+
+class NumberResult extends FormulaResult{
+  final Number value;
+  const NumberResult(this.value);
+}
+
 class FormulaEvaluator {
   final D4rt _interpreter;
 
@@ -34,7 +48,7 @@ class FormulaEvaluator {
     prepareInterpreter(_interpreter);
   }
 
-  static Number getNumberValueOf(String s){
+  static Number _getNumberValueOf(String s){
     return double.parse(s);
   }
 
@@ -44,12 +58,12 @@ class FormulaEvaluator {
       name: 'MyMath',
       staticMethods: {
         'myPow': (visitor, positionalArgs, namedArgs) {
-          final Number base = getNumberValueOf( positionalArgs[0].toString() );
+          final Number base = _getNumberValueOf( positionalArgs[0].toString() );
-          final Number exp = getNumberValueOf( positionalArgs[1].toString() );
+          final Number exp = _getNumberValueOf( positionalArgs[1].toString() );
           return MyMath.myPow(base,exp);
         },
         'myLog': (visitor, positionalArgs, namedArgs) {
-          final Number x = getNumberValueOf( positionalArgs[0].toString() );
+          final Number x = _getNumberValueOf( positionalArgs[0].toString() );
           return MyMath.myLog(x);
         },
       }
@@ -58,7 +72,7 @@ class FormulaEvaluator {
     interpreter.registerBridgedClass(myMathDefinition, "package:d4rt_formulas.dart");
   }
 
-  static dynamic evaluateExpression(String code, [D4rt? interpreter]) {
+  static FormulaResult evaluateExpression(String code, [D4rt? interpreter]) {
     final d4rtInterpreter = interpreter ?? createDefaultInterpreter();
     prepareInterpreter(d4rtInterpreter);
     final d4rtCode = """
@@ -71,7 +85,16 @@ class FormulaEvaluator {
       }""";
     //print("evaluateExpression:\n$d4rtCode");
     final result = d4rtInterpreter.execute(source: d4rtCode);
-    return result.toDouble();
+    switch ( result ){
+      case int value:
+        return NumberResult(value.toDouble());
+      case Number value:
+        return NumberResult(value);
+      case String value:
+        return StringResult(value);
+      default:
+        throw FormulaEvaluationException( "Unexpected result type: ${result.runtimeType} -- $result" );
+    }
   }
   
   dynamic evaluate(Formula formula, Map<String, dynamic> inputValues) {