Refactor logger and enable/disable log trace

README.md

@@ -76,4 +76,12 @@ let f = (\x -> x) in (app (app (\a b -> b) (app f True)) (app f 1))
                 1 => IntLiteral
         
     
-```
+```
+
+## REPL
+
+### Commandes
+
+- Pour quitter `:q`
+- Pour afficher l'aide `:h`
+- Pour activer/désactiver les informations des étapes d'inférence et d'unification `:log`

src/main/java/fr/imt/inference/ConstraintCollection.java

@@ -13,7 +13,7 @@
  */
 public class ConstraintCollection implements Substituable<ConstraintCollection> {
 
-    private final Logger logger = new Logger();
+    private final Logger logger = Logger.instance;
 
     private Deque<Constraint> constraints = new LinkedList<>();
 

src/main/java/fr/imt/inference/Environment.java

@@ -13,7 +13,7 @@
 
 public class Environment implements FreeTypeVariableContainer {
 
-    private Logger logger = new Logger();
+    private Logger logger = Logger.instance;
     private Map<Expression, Scheme> env;
 
     public Environment() {

src/main/java/fr/imt/inference/ExpressionInferer.java

@@ -12,7 +12,7 @@
 
 public class ExpressionInferer implements Inferable<Expression, Type> {
 
-    private Logger logger = new Logger();
+    private Logger logger = Logger.instance;
 
     @Override
     public Either<String, Type> infer(Expression expression) {

src/main/java/fr/imt/inference/Unifiyer.java

@@ -10,7 +10,7 @@
 
 public class Unifiyer {
 
-    private Logger logger = new Logger();
+    private Logger logger = Logger.instance;
 
     public SubstitutionCollection runSolve(ConstraintCollection constraints) throws InfiniteTypeException, UnificationMismatchException, UnificationFailureException {
         return solve(new SubstitutionCollection(), constraints);

src/main/java/fr/imt/inference/ast/Application.java

@@ -13,7 +13,7 @@ public class Application implements Expression {
     public final Expression body;
     public final Expression argument;
 
-    private final Logger logger = new Logger();
+    private final Logger logger = Logger.instance;
 
     public Application(
             Expression body,

src/main/java/fr/imt/inference/ast/Lambda.java

@@ -14,7 +14,7 @@ public class Lambda implements Expression {
     public final Variable identifier;
     public final Expression body;
 
-    private Logger logger = new Logger();
+    private Logger logger = Logger.instance;
 
     public Lambda(Variable identifier, Expression body) {
         this.identifier = identifier;

src/main/java/fr/imt/inference/ast/Let.java

@@ -11,7 +11,7 @@ public class Let implements Expression {
     public final Expression definition;
     public final Expression body;
 
-    private final Logger logger = new Logger();
+    private final Logger logger = Logger.instance;
 
     public Let(Variable identifier, Expression definition, Expression body) {
         this.identifier = identifier;

src/main/java/fr/imt/inference/type/Type.java

@@ -13,7 +13,7 @@
  * - type variable
  */
 public interface Type extends Substituable<Type>, FreeTypeVariableContainer {
-    Logger logger = new Logger();
+    Logger logger = Logger.instance;
 
     boolean isTypeVariable();
 

src/main/java/fr/imt/logger/Color.java

@@ -2,10 +2,34 @@
 
 public class Color {
 
-    private static final String ANSI_RESET = "\u001B[0m";
-    private static final String ANSI_RED = "\u001B[31m";
+    public static final String ANSI_RESET = "\u001B[0m";
+    public static final String ANSI_BLACK = "\u001B[30m";
+    public static final String ANSI_RED = "\u001B[31m";
+    public static final String ANSI_GREEN = "\u001B[32m";
+    public static final String ANSI_YELLOW = "\u001B[33m";
+    public static final String ANSI_BLUE = "\u001B[34m";
+    public static final String ANSI_PURPLE = "\u001B[35m";
+    public static final String ANSI_CYAN = "\u001B[36m";
+    public static final String ANSI_WHITE = "\u001B[37m";
+    public static final String ANSI_BLACK_BOLD_BRIGHT = "\033[1;90m";
+
+    private static String format(String color, String message) {
+        return String.format("%s%s%s", color, message, ANSI_RESET);
+    }
 
     public static String red(String message) {
-        return String.format("%s%s%s", ANSI_RED, message, ANSI_RESET);
+        return format(ANSI_RED, message);
+    }
+
+    public static String grey(String message) {
+        return format(ANSI_BLACK_BOLD_BRIGHT, message);
+    }
+
+    public static String green(String message) {
+        return format(ANSI_GREEN, message);
+    }
+
+    public static String purple(String message) {
+        return format(ANSI_PURPLE, message);
     }
 }

src/main/java/fr/imt/logger/Logger.java

@@ -6,22 +6,14 @@
 
 public class Logger {
 
-    private static final String ANSI_RESET = "\u001B[0m";
-    private static final String ANSI_BLACK = "\u001B[30m";
-    private static final String ANSI_RED = "\u001B[31m";
-    private static final String ANSI_GREEN = "\u001B[32m";
-    private static final String ANSI_YELLOW = "\u001B[33m";
-    private static final String ANSI_BLUE = "\u001B[34m";
-    private static final String ANSI_PURPLE = "\u001B[35m";
-    private static final String ANSI_CYAN = "\u001B[36m";
-    private static final String ANSI_WHITE = "\u001B[37m";
-
-    private static final String ANSI_BLACK_BOLD_BRIGHT = "\033[1;90m";
+    public static final Logger instance = new Logger();
 
+    private StringBuilder log = new StringBuilder();
     private String className;
 
-    public Logger() {
+    private Logger() {
         this.className = this.prettyClassName(new Exception().getStackTrace()[1].getClassName());
+        this.log = new StringBuilder();
     }
 
     private String prettyClassName(String className) {
@@ -41,15 +33,24 @@ private String prettyClassName(String className) {
     private void printMessage(String level, String color, String message) {
         String spaces = List.range(0, 28 - this.className.length()).map(e -> " ").mkString("");
 
-        System.out.println(String.format("%s%5s%s %s[%s]%s %s %s", color, level, ANSI_RESET, ANSI_BLACK_BOLD_BRIGHT, this.className, ANSI_RESET, spaces, message));
+        log.append(String.format("%s%5s%s %s[%s]%s %s %s \n", color, level, Color.ANSI_RESET, Color.ANSI_BLACK_BOLD_BRIGHT, this.className, Color.ANSI_RESET, spaces, message));
     }
 
     public void debug(String msg) {
-        this.printMessage("DEBUG", ANSI_GREEN, msg);
+        this.printMessage("DEBUG", Color.ANSI_GREEN, msg);
     }
 
     public void trace(String msg) {
-        this.printMessage("TRACE", ANSI_BLUE, msg);
+        this.printMessage("TRACE", Color.ANSI_BLUE, msg);
+    }
+
+    public void reset() {
+        this.log = new StringBuilder();
+    }
+
+    @Override
+    public String toString() {
+        return log.toString();
     }
 
     private class ClassNameElement {

src/main/java/fr/imt/parser/Repl.java

@@ -1,43 +1,66 @@
 package fr.imt.parser;
 
 import fr.imt.logger.Color;
+import fr.imt.logger.Logger;
 
 import java.util.Scanner;
 
 public class Repl<T> {
 
     private final Parsable<T> parser;
     private final ReplProcessable<T> processor;
+    private boolean showLog;
 
     public Repl(Parsable<T> parser, ReplProcessable<T> processor) {
         this.parser = parser;
         this.processor = processor;
+        this.showLog = true;
     }
 
     public void run() {
         Scanner scanner = new Scanner(System.in);
 
         System.out.println("Hindley Milner Type System");
+        showHelp();
 
         while (true) {
             System.out.print("> ");
             String line = scanner.nextLine().trim();
 
-            // TODO: implement a set of commands
+            // TODO: refactor by creating a command handler service
             if (line.equals(":q")) {
                 break;
+            } else if (line.equals(":log")) {
+                this.showLog = !this.showLog;
+                System.out.println(Color.grey("Log " + (this.showLog ? "enabled" : "disabled")));
+            } else if (line.equals(":h")) {
+                showHelp();
+            } else {
+                process(line);
             }
+        }
 
-            String res = parser.parse(line)
-                .fold(
-                    parseError -> Color.red("Parsing error : " + parseError),
-                    processor::process
-                );
+        System.out.println(Color.grey("Bye!"));
+    }
 
-            System.out.println(res);
-        }
+    private void process(String line) {
+        String result = parser.parse(line)
+            .fold(
+                parseError -> Color.red("Parsing error : " + parseError),
+                processor::process
+            );
+
+        if (this.showLog) System.out.print(Logger.instance);
+
+        System.out.println(Color.purple(result));
+    }
 
-        System.out.println("Bye!");
+    private void showHelp() {
+        System.out.println("\nCommands:");
+        System.out.println("\t\t- " + Color.green(":log") + "\t: enable/disable logs");
+        System.out.println("\t\t- " + Color.green(":h") + "\t: help");
+        System.out.println("\t\t- " + Color.green(":q") + "\t: quit");
+        System.out.println();
     }
 
 }