From 9fb39b1cff12bb2ec80ac9cd798f8a50069f4afc Mon Sep 17 00:00:00 2001
From: Michael Williamson <mike@zwobble.org>
Date: Fri, 22 Apr 2016 22:16:11 +0100
Subject: Handle try-with-resources

---
 .../frontends/java/JavaStatementReader.java        | 42 +++++++++++++++-------
 .../java/org/zwobble/couscous/util/ExtraLists.java |  2 +-
 2 files changed, 31 insertions(+), 13 deletions(-)

(limited to 'src/main/java/org/zwobble')

diff --git a/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java b/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java
index c3c4f21..e75585f 100644
--- a/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java
+++ b/src/main/java/org/zwobble/couscous/frontends/java/JavaStatementReader.java
@@ -1,5 +1,6 @@
 package org.zwobble.couscous.frontends.java;
 
+import com.google.common.collect.Lists;
 import org.eclipse.jdt.core.dom.*;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.ast.sugar.SwitchCaseNode;
@@ -167,11 +168,24 @@ class JavaStatementReader {
 
     private List<StatementNode> readTryStatement(TryStatement statement) {
         @SuppressWarnings("unchecked")
-        List<CatchClause> catchClauses = statement.catchClauses();
-        return list(tryStatement(
-            readStatement(statement.getBody()),
-            eagerMap(catchClauses, this::readCatchClause),
-            statement.getFinally() == null ? list() : readStatement(statement.getFinally())));
+        List<VariableDeclarationExpression> resources = statement.resources();
+        List<LocalVariableDeclarationNode> resourceDeclarations = eagerFlatMap(resources, this::readVariableDeclarationExpression);
+        List<StatementNode> body = readStatement(statement.getBody());
+        for (LocalVariableDeclarationNode resource : Lists.reverse(resourceDeclarations)) {
+            body = list(
+                resource,
+                tryStatement(body, list(), list(expressionStatement(methodCall(reference(resource), "close", list(), Types.VOID))))
+            );
+        }
+        @SuppressWarnings("unchecked")
+        List<CatchClause> javaCatchClauses = statement.catchClauses();
+        List<ExceptionHandlerNode> catchClauses = eagerMap(javaCatchClauses, this::readCatchClause);
+        List<StatementNode> finallyBody = statement.getFinally() == null ? list() : readStatement(statement.getFinally());
+        if (catchClauses.isEmpty() && finallyBody.isEmpty()) {
+            return body;
+        } else {
+            return list(tryStatement(body, catchClauses, finallyBody));
+        }
     }
 
     private ExceptionHandlerNode readCatchClause(CatchClause clause) {
@@ -191,18 +205,16 @@ class JavaStatementReader {
     }
 
     private List<StatementNode> readForStatement(ForStatement statement) {
-        List javaInitialisers = statement.initializers();
+        @SuppressWarnings("unchecked")
+        List<VariableDeclarationExpression> javaInitialisers = statement.initializers();
         if (javaInitialisers.size() != 1) {
             throw new UnsupportedOperationException();
         }
-        VariableDeclarationExpression javaDeclaration = (VariableDeclarationExpression) javaInitialisers.get(0);
-        @SuppressWarnings("unchecked")
-        List<VariableDeclarationFragment> fragments = javaDeclaration.fragments();
         @SuppressWarnings("unchecked")
         List<Expression> updaters = statement.updaters();
 
         return append(
-            readDeclarationFragments(fragments, typeOf(javaDeclaration.getType())),
+            readVariableDeclarationExpression(javaInitialisers.get(0)),
             whileLoop(
                 readExpression(Types.BOOLEAN, statement.getExpression()),
                 concat(
@@ -232,10 +244,16 @@ class JavaStatementReader {
         @SuppressWarnings("unchecked")
         List<VariableDeclarationFragment> fragments = statement.fragments();
         Type type = typeOf(statement.getType());
-        return readDeclarationFragments(fragments, type);
+        return (List)readDeclarationFragments(fragments, type);
+    }
+
+    private List<LocalVariableDeclarationNode> readVariableDeclarationExpression(VariableDeclarationExpression expression) {
+        @SuppressWarnings("unchecked")
+        List<VariableDeclarationFragment> fragments = expression.fragments();
+        return readDeclarationFragments(fragments, typeOf(expression.getType()));
     }
 
-    private List<StatementNode> readDeclarationFragments(
+    private List<LocalVariableDeclarationNode> readDeclarationFragments(
         List<VariableDeclarationFragment> fragments,
         Type type
     ) {
diff --git a/src/main/java/org/zwobble/couscous/util/ExtraLists.java b/src/main/java/org/zwobble/couscous/util/ExtraLists.java
index 3ee0ce3..76d3de7 100644
--- a/src/main/java/org/zwobble/couscous/util/ExtraLists.java
+++ b/src/main/java/org/zwobble/couscous/util/ExtraLists.java
@@ -33,7 +33,7 @@ public class ExtraLists {
         return concat(list(value), list);
     }
 
-    public static <T> List<T> append(List<T> list, T value) {
+    public static <T> List<T> append(List<? extends T> list, T value) {
         return Stream.concat(list.stream(), Stream.of(value)).collect(Collectors.toList());
     }
 
-- 
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