Add java evaluator

7 files changed, 199 insertions, 0 deletions

diff --git a/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/LCEvaluator.java b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/LCEvaluator.java
new file mode 100644
index 0000000..b0fe69b
--- /dev/null
+++ b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/LCEvaluator.java
@@ -0,0 +1,59 @@
+package org.lambdanantes.lcgoji;
+
+import org.lambdanantes.lcgoji.ast.Abs;
+import org.lambdanantes.lcgoji.ast.App;
+import org.lambdanantes.lcgoji.ast.Term;
+import org.lambdanantes.lcgoji.ast.Var;
+
+import static org.lambdanantes.lcgoji.ast.Abs.λ;
+import static org.lambdanantes.lcgoji.ast.App.apply;
+
+public class LCEvaluator {
+
+    public static Term evaluate(Term term) {
+        switch (term) {
+            case Var var -> {
+                return var;
+            }
+            case Abs abs -> {
+                return abs;
+            }
+            case App app -> {
+                switch (app.left) {
+                    case Abs abs -> {
+                        return substitute(abs.body, abs.arg, app.right);
+                    }
+                    case App _app -> {
+                        return app;
+                    }
+                    case Var _var -> {
+                        return app;
+                    }
+                }
+            }
+        }
+    }
+
+    private static Term substitute(Term body, String arg, Term val) {
+        switch (body) {
+            case Var var -> {
+                if (var.name.equals(arg)) {
+                    return val;
+                } else {
+                    return body;
+                }
+            }
+            case App app -> {
+                return apply(substitute(app.left, arg, val), substitute(app.right, arg, val));
+            }
+            case Abs abs -> {
+                if (abs.arg.equals(arg)) {
+                    // Pas de substitution des variables redéfinies
+                    return abs;
+                } else {
+                    return λ(abs.arg, substitute(abs.body, arg, val));
+                }
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/Main.java b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/Main.java
new file mode 100644
index 0000000..76cb839
--- /dev/null
+++ b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/Main.java
@@ -0,0 +1,49 @@
+package org.lambdanantes.lcgoji;
+
+import lombok.extern.slf4j.Slf4j;
+import org.apache.http.client.fluent.Request;
+import org.apache.http.client.fluent.Response;
+import org.apache.http.entity.StringEntity;
+
+import static spark.Spark.*;
+
+@Slf4j
+public class Main {
+
+    public static final String TEAM_NAME = "LCGOJI";
+    public static final int SELF_PORT = 8888;
+    public static final String SELF_URL = "http://127.0.0.1:" + SELF_PORT;
+    public static final String TESTER_URL = "http://127.0.0.1:8080";
+
+    public static void main(String[] args) throws Exception {
+        port(SELF_PORT);
+
+        before((request, response) -> log.info("Requête entrante : " + request.requestMethod() + " " + request.pathInfo() + ", query params : " + request.queryString()));
+
+        // API pour l'évaluation de λ-term
+        // Le body est une S-expression sous sa forme textuelle
+        post("/eval", (request, response) -> {
+            String body = request.body();
+            log.info("Demande d'évaluation de l'expression : " + body);
+
+            // TODO Parser, contruire l'AST, l'évaluer
+            String result = body; // Renvoie la s-expression à l'identique pour le moment
+
+            log.info("Réponse envoyée : " + body);
+
+            return result.getBytes();
+        });
+
+        init();
+
+        // Enregistrement de notre API auprès du tester d'API
+        String jsonBody = "{\"url\":\"" + SELF_URL + "/eval\", \"name\": \"" + TEAM_NAME + "\"}";
+        Response response = Request.Post(TESTER_URL + "/register")
+                .addHeader("Content-type", "application/json")
+                .body(new StringEntity(jsonBody))
+                .execute();
+
+        log.info("Résultat de l'enregistrement : "+response.returnContent().toString());
+    }
+
+}
\ No newline at end of file
diff --git a/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Abs.java b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Abs.java
new file mode 100644
index 0000000..9d1c146
--- /dev/null
+++ b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Abs.java
@@ -0,0 +1,26 @@
+package org.lambdanantes.lcgoji.ast;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+
+import static org.lambdanantes.lcgoji.ast.Var.var;
+
+@AllArgsConstructor(access = AccessLevel.PROTECTED)
+@EqualsAndHashCode
+public final class Abs implements Term {
+
+    public static final Abs IDENTITY = λ("x", var("x"));
+
+    public String arg;
+    public Term body;
+
+    public static Abs λ(String arg, Term body) {
+        return new Abs(arg, body);
+    }
+
+    @Override
+    public String toString() {
+        return "λ" + arg + "." + body;
+    }
+}
\ No newline at end of file
diff --git a/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/App.java b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/App.java
new file mode 100644
index 0000000..2f3e04d
--- /dev/null
+++ b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/App.java
@@ -0,0 +1,22 @@
+package org.lambdanantes.lcgoji.ast;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+
+@AllArgsConstructor(access = AccessLevel.PROTECTED)
+@EqualsAndHashCode
+public final class App implements Term {
+
+    public Term left;
+    public Term right;
+
+    public static App apply(Term left, Term right) {
+        return new App(left, right);
+    }
+
+    @Override
+    public String toString() {
+        return "(" + left + ") " + right;
+    }
+}
\ No newline at end of file
diff --git a/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Term.java b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Term.java
new file mode 100644
index 0000000..2dcc9fe
--- /dev/null
+++ b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Term.java
@@ -0,0 +1,5 @@
+package org.lambdanantes.lcgoji.ast;
+
+public sealed interface Term permits Var, Abs, App {
+
+}
\ No newline at end of file
diff --git a/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Var.java b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Var.java
new file mode 100644
index 0000000..ed710b6
--- /dev/null
+++ b/java/lcgoji/src/main/java/org/lambdanantes/lcgoji/ast/Var.java
@@ -0,0 +1,21 @@
+package org.lambdanantes.lcgoji.ast;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+
+@AllArgsConstructor(access = AccessLevel.PROTECTED)
+@EqualsAndHashCode
+public final class Var implements Term{
+
+    public String name;
+
+    public static Var var(String name) {
+        return new Var(name);
+    }
+
+    @Override
+    public String toString() {
+        return name;
+    }
+}
\ No newline at end of file
diff --git a/java/lcgoji/src/main/resources/log4j2.xml b/java/lcgoji/src/main/resources/log4j2.xml
new file mode 100644
index 0000000..f938085
--- /dev/null
+++ b/java/lcgoji/src/main/resources/log4j2.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration monitorInterval="60">
+    <appenders>
+        <console name="console" target="SYSTEM_OUT">
+            <patternLayout pattern="%d{HH:mm:ss} [%t] %-5level %logger{36} - %msg%n"/>
+        </console>
+    </appenders>
+
+    <loggers>
+        <root level="debug">
+            <appender-ref ref="console"/>
+        </root>
+        <logger name="org.eclipse.jetty" level="warn"/>
+        <logger name="spark" level="info"/>
+    </loggers>
+</configuration>
+