Refactoring (#81)

README.md

@@ -2199,12 +2199,11 @@ The source code includes a `Visitor` implementation
 whose sole purpose is to do this, `AstPrinter`. When enabled, it will
 print the AST to the logs.
 
-You can enable it by passing an `expression.Evaluator.Config` option to the `run` 
+You can enable it by passing an `expression.Configuration` option to the `run` 
 method with the `printAst` option enabled :
 
 ```apex
-expression.Evaluator.Config config = new expression.Evaluator.Config();
-config.printAst = true;
+expression.Configuration config = new expression.Configuration().printAst();
 Object value = expression.Evaluator.run('AND(true, false, 1=1)', config);
 // Outputs to the logs:
 // (AND true false (= 1 1))

expression-components/main/ui/controllers/FormulaEvaluatorUiController.cls

@@ -14,8 +14,7 @@ public with sharing class FormulaEvaluatorUiController {
     @AuraEnabled(Cacheable=true)
     public static Object evaluate(String recordId, String formula, Boolean respectSharing) {
         try {
-            Evaluator.Config config = new Evaluator.Config();
-            config.sharing = respectSharing ? Evaluator.SharingMode.WITH : Evaluator.SharingMode.WITHOUT;
+            Configuration config = new Configuration().respectSharing(respectSharing);
             if (String.isBlank(recordId)) {
                 return Evaluator.run(formula, config);
             } else {

expression-src/main/api/Configuration.cls

@@ -0,0 +1,43 @@
+global with sharing class Configuration {
+    public static Configuration.SharingMode evaluationSharingMode;
+
+    global enum SharingMode {
+        WITH,
+        WITHOUT
+    }
+
+    global SharingMode sharing = SharingMode.WITH;
+    global Boolean printAst = false;
+    public Boolean withDiagnostics = false;
+
+    global Configuration respectSharing(Boolean respect) {
+        sharing = respect ? SharingMode.WITH : SharingMode.WITHOUT;
+        return this;
+    }
+
+    global Configuration printAst() {
+        printAst = true;
+        return this;
+    }
+
+    global Configuration withDiagnostics() {
+        withDiagnostics = true;
+        return this;
+    }
+
+    public void subscribe(EvaluatorEventNotifier notifier) {
+        // Always subscribe to the event that sets the sharing mode
+        // at the beginning of the evaluation regardless of configuration.
+        notifier.subscribe(OnEvaluationStartEvent.class, new EvaluationSharingModeSetter());
+
+        if (this.printAst) {
+            notifier.subscribe(OnAfterParseEvent.class, new AstPrinter());
+        }
+
+        if (this.withDiagnostics) {
+            EvaluationDiagnosticsListener diagnosticsListener = new EvaluationDiagnosticsListener();
+            notifier.subscribe(OnEvaluationStartEvent.class, diagnosticsListener);
+            notifier.subscribe(OnEvaluationEndEvent.class, diagnosticsListener);
+        }
+    }
+}

expression-src/main/api/Evaluator.cls

@@ -1,16 +1,14 @@
 /**
  * @description Evaluates a formula and returns the result.
  */
-global with sharing class Evaluator {
-    public static SharingMode evaluationSharingMode;
-
+global with sharing abstract class Evaluator {
     /**
      * @description Evaluates a formula and returns the result.
      * @param formula The formula to evaluate.
      * @return The result of the formula.
      */
     global static Object run(String formula) {
-        return run(formula, new Config());
+        return run(formula, new Configuration());
     }
 
     /**
@@ -20,7 +18,7 @@ global with sharing class Evaluator {
      *        the evaluation.
      * @return The result of the formula.
      */
-    global static Object run(String formula, Config config) {
+    global static Object run(String formula, Configuration config) {
         return run(formula, (SObject) null, config);
     }
 
@@ -33,7 +31,7 @@ global with sharing class Evaluator {
      * @return The result of the formula.
      */
     global static Object run(String formula, SObject context) {
-        return run(formula, context, new Config());
+        return run(formula, context, new Configuration());
     }
 
     /**
@@ -46,9 +44,8 @@ global with sharing class Evaluator {
      *        the evaluation.
      * @return The result of the formula.
      */
-    global static Object run(String formula, SObject context, Config config) {
-        Expr pipedExpression = parseExpression(formula, config);
-        return interpretWithContext(context, pipedExpression, config);
+    global static Object run(String formula, SObject context, Configuration config) {
+        return EvaluatorResolver.forRecord(context).evaluate(formula, config).result;
     }
 
     /**
@@ -60,7 +57,7 @@ global with sharing class Evaluator {
      * @return The result of the formula.
      */
     global static Object run(String formula, Id recordId) {
-        return run(formula, recordId, new Config());
+        return run(formula, recordId, new Configuration());
     }
 
     /**
@@ -73,58 +70,7 @@ global with sharing class Evaluator {
      *        the evaluation.
      * @return The result of the formula.
      */
-    global static Object run(String formula, Id recordId, Config config) {
-        Expr pipedExpression = parseExpression(formula, config);
-        SObject record = getRecord(recordId, pipedExpression);
-        return interpretWithContext(record, pipedExpression, config);
-    }
-
-    private static Expr parseExpression(String formula, Config config) {
-        evaluationSharingMode = config.sharing;
-        Scanner scanner = new Scanner(formula);
-        List<Token> tokens = scanner.scanTokens();
-
-        Parser parser = new Parser(tokens);
-        Expr expression = parser.parse();
-
-        if (config.printAst) {
-            AstPrinter printer = new AstPrinter();
-            printer.printAst(expression);
-        }
-
-        PipeResolver pipeInterpreter = new PipeResolver();
-        Expr pipedExpression = pipeInterpreter.resolve(expression);
-        return pipedExpression;
-    }
-
-    private static SObject getRecord(Id recordId, Expr pipedExpression) {
-        ContextResolver ctxInterpreter = new ContextResolver(recordId);
-        return ctxInterpreter.build(pipedExpression);
-    }
-
-    private static Object interpretWithContext(SObject record, Expr pipedExpression, Config config) {
-        Environment env = new Environment(record);
-        IInterpreter interpreter = getInterpreter(env, config);
-        return interpreter.interpret(pipedExpression);
-    }
-
-    global enum SharingMode {
-        WITH,
-        WITHOUT
-    }
-
-    global class Config {
-        global SharingMode sharing = SharingMode.WITH;
-        global Boolean printAst = false;
-        public Boolean withDiagnostics = false;
-    }
-
-    private static IInterpreter getInterpreter(Environment env, Config config) {
-        IInterpreter mainInterpreter = new Interpreter(env);
-        if (config.withDiagnostics) {
-            return new DiagnosticsDecorator(mainInterpreter);
-        } else {
-            return mainInterpreter;
-        }
+    global static Object run(String formula, Id recordId, Configuration config) {
+        return EvaluatorResolver.forId(recordId).evaluate(formula, config).result;
     }
 }

expression-src/main/editor/controllers/PlaygroundController.cls

@@ -33,16 +33,30 @@ public with sharing class PlaygroundController {
         return toReturn;
     }
 
+    // Record Id is of type String because we could receive an empty String
+    // from the front-end, so we can't use Id as the type in that case.
     @AuraEnabled
-    public static Result validate(String expr, Id recordId) {
+    public static Result validate(String expr, String recordId) {
         Result toReturn = new Result();
-        Evaluator.Config config = new Evaluator.Config();
-        config.withDiagnostics = true;
+        Configuration config = new Configuration().withDiagnostics().printAst();
         try {
+            EvaluationResult evalResult;
             if (String.isNotBlank(recordId)) {
-                toReturn.result = Evaluator.run(expr, recordId, config);
+                evalResult = EvaluatorResolver.forId(recordId).evaluate(expr, config);
             } else {
-                toReturn.result = Evaluator.run(expr, config);
+                evalResult = EvaluatorResolver.withoutContext().evaluate(expr, config);
+            }
+
+            toReturn.result = evalResult.result;
+
+            if (evalResult.additionalData.containsKey('diagnostics')) {
+                EvaluationDiagnosticsListener.DiagnosticsResult diagnosticsResult =
+                    (EvaluationDiagnosticsListener.DiagnosticsResult)evalResult.additionalData.get('diagnostics');
+                toReturn.diagnostics = new Diagnostics(diagnosticsResult);
+            }
+
+            if (evalResult.additionalData.containsKey('ast')) {
+                toReturn.ast = evalResult.additionalData.get('ast');
             }
         } catch (Exceptions.PositionAwareException e) {
             EvaluationError error = new EvaluationError();
@@ -60,8 +74,6 @@ public with sharing class PlaygroundController {
             toReturn.error = error;
         }
 
-        toReturn.diagnostics = new Diagnostics(DiagnosticsDecorator.result);
-
         return toReturn;
     }
 
@@ -74,6 +86,9 @@ public with sharing class PlaygroundController {
 
         @AuraEnabled
         public Diagnostics diagnostics;
+
+        @AuraEnabled
+        public Object ast;
     }
 
     public class Diagnostics {
@@ -89,7 +104,7 @@ public with sharing class PlaygroundController {
         @AuraEnabled
         public Integer queryRows;
 
-        public Diagnostics(DiagnosticsDecorator.DiagnosticsResult result) {
+        public Diagnostics(EvaluationDiagnosticsListener.DiagnosticsResult result) {
             this.cpuTime = result?.cpuTime;
             this.dmlStatements = result?.dmlStatements;
             this.queries = result?.queries;

expression-src/main/editor/lwc/playground/playground.html

@@ -40,13 +40,19 @@
                                 </lightning-tab>
                                 <lightning-tab label="Diagnostics">
                                     <ul>
-                                        <li><strong>CPU Time:</strong> {diagnostics.cpuTime}<span
-                                            if:true={diagnostics.cpuTime}>ms</span></li>
+                                        <li><strong>CPU Time (ms):</strong> {diagnostics.cpuTime}<span
+                                            if:true={diagnostics.cpuTime}></span></li>
                                         <li><strong>DML Statements:</strong> {diagnostics.dmlStatements}</li>
                                         <li><strong>Queries:</strong> {diagnostics.queries}</li>
                                         <li><strong>Query Rows:</strong> {diagnostics.queryRows}</li>
                                     </ul>
                                 </lightning-tab>
+                                <lightning-tab label="AST">
+                                    <pre class={resultColor}>
+                                        <lightning-formatted-rich-text
+                                                value={ast}></lightning-formatted-rich-text>
+                                    </pre>
+                                </lightning-tab>
                             </lightning-tabset>
                         </div>
                     </div>

expression-src/main/editor/lwc/playground/playground.js

@@ -7,7 +7,13 @@ export default class Monaco extends LightningElement {
   recordId;
   iframeUrl = `${monaco}/main.html`;
   result = {};
-  diagnostics = {};
+  diagnostics = {
+    cpuTime: "Unavailable",
+    dmlStatements: "Unavailable",
+    queries: "Unavailable",
+    queryRows: "Unavailable",
+  };
+  ast = "";
 
   async iframeLoaded() {
     const functionKeywords = await getFunctions();
@@ -40,7 +46,22 @@ export default class Monaco extends LightningElement {
       }
     }
 
-    this.diagnostics = result.diagnostics;
+    this._setDiagnostics(result);
+    this.ast = result.ast ?
+      this._syntaxHighlight(JSON.stringify(result.ast, null, 4)) :
+      "";
+  }
+
+  _setDiagnostics(result) {
+    this.diagnostics = Object.keys(result.diagnostics).reduce((acc, key) => {
+      acc[key] = result.diagnostics[key] ?? "Unavailable";
+      return acc;
+    }, {
+      cpuTime: "Unavailable",
+      dmlStatements: "Unavailable",
+      queries: "Unavailable",
+      queryRows: "Unavailable",
+    });
   }
 
   handleInputChange(event) {

expression-src/main/src/helpers/QRunner.cls

@@ -7,7 +7,7 @@ public inherited sharing abstract class QRunner {
             return mockRunner;
         }
 
-        if (Evaluator.evaluationSharingMode == Evaluator.SharingMode.WITH) {
+        if (Configuration.evaluationSharingMode == Configuration.SharingMode.WITH) {
             return new WithSharingRunner();
         } else {
             return new WithoutSharingRunner();

expression-src/main/src/interpreter/Interpreter.cls

@@ -1,4 +1,4 @@
-public with sharing class Interpreter implements IInterpreter, Visitor {
+public with sharing class Interpreter implements Visitor {
     private final Environment env;
 
     private Boolean inListLiteral = false;

expression-src/main/src/interpreter/std-lib/CollectionFunctions.cls

@@ -78,7 +78,7 @@ public with sharing class CollectionFunctions {
         }
 
         public override Arity getArity() {
-            return Arity.atLeast(1);
+            return Arity.atLeast(0);
         }
     }