Add support for switch statement w/ breaks

CHANGELOG.md

@@ -1,9 +1,10 @@
 Rocker Templates by Fizzed
 ==========================
 
-## TBD
+#### 2.0.0 - 2024-11-06
 
- - Java 8 is now minimum supported version (Java 21 will no longer compile < 8)
+ - Java 7 support dropped. Java 8 is now minimum supported version (Java 21 will no longer compile < 8).
+ - New switch statement feature (@asaf-wizzdi)
  - Merged rocker-test-java7 and rocker-test-java8 modules together into rocker-test-template
  - Blaze build system updated to v1.5.1 (which works on Java 21)
  - CI automated tests for Java 21

docs/SYNTAX.md

@@ -196,6 +196,38 @@ Note that Rocker has intelligence to skip template content that includes ```{```
 and ```}``` characters such as JavaScript or CSS.  You will not need to escape
 these characters as long as you have matching left and right curly brackets.
 
+### Switch - case - default blocks (@switch)
+
+Standard Java switch - case - defai;t control flow. The left curly character ```{``` indicates
+the start of a block and the right curly character ```}``` marks the end.
+
+The ```else if``` option is available as of v0.16.0.
+
+Switch block with case and default example.
+
+    @switch (s) {
+        case ("a") { 
+            i am in the "a" block
+        }
+        case ("b") {
+            i am in the "b" block
+        }
+        default {
+            i am in the "default" block
+        }
+    }
+
+Without a default block.
+
+    @switch (v) {
+        case (1) { 
+            i am in the "a" block
+        }
+        case (2) {
+            i am in the "b" block
+        }
+    }
+
 ### With blocks (set one or more variables) (@with)
 
 As of v0.12.0 a `@with` block sets a variable to a value within a scoped block. Once the block

rocker-compiler/src/main/java/com/fizzed/rocker/compiler/JavaGenerator.java

@@ -975,33 +975,53 @@ else if(unit instanceof SwitchBlock){
 
                 SwitchBlock block = (SwitchBlock) unit;
 
+                // break support via try and catch mechanism (works across lambdas!)
+                tab(w, depth+indent)
+                    .append("try {").append(CRLF);
+
+                depth++;
+
                 tab(w, depth+indent)
                         .append("switch ")
                         .append(block.getExpression())
                         .append(" {").append(CRLF);
 
                 blockEnd.push("}");
+
                 depth++;
             } else if (unit instanceof SwitchBlockEnd) {
                 depth--;
 
                 tab(w, depth+indent)
                         .append(blockEnd.pop())
                         .append(" // switch end ").append(sourceRef(unit)).append(CRLF);
+
+                depth--;
+
+                // break support via try and catch mechanism (works across lambdas!)
+                tab(w, depth+indent)
+                    .append("} catch (").append(BreakException.class.getCanonicalName()).append(" e) {") .append(CRLF);
+
+                tab(w, depth+indent+1)
+                    .append("// support for breaking switch statements").append(CRLF);
+
+                tab(w, depth+indent)
+                    .append("}").append(CRLF);
+
             } else if (unit instanceof SwitchCaseBlock) {
 
                 SwitchCaseBlock block = (SwitchCaseBlock) unit;
 
                 tab(w, depth+indent)
                         .append("case ")
                         .append(block.getExpression())
-                        .append("->")
+                        .append(": ")
                         .append(" {").append(CRLF);
 
                 blockEnd.push("}");
+
                 depth++;
-            }
-            else if (unit instanceof SwitchCaseBlockEnd) {
+            } else if (unit instanceof SwitchCaseBlockEnd) {
                 depth--;
 
                 tab(w, depth+indent)
@@ -1011,7 +1031,7 @@ else if (unit instanceof SwitchCaseBlockEnd) {
 
                 tab(w, depth+indent)
                         .append("default ")
-                        .append("->")
+                        .append(": ")
                         .append(" {").append(CRLF);
 
                 blockEnd.push("}");

rocker-compiler/src/main/java/com/fizzed/rocker/compiler/TemplateParser.java

@@ -754,8 +754,8 @@ public void enterValue(RockerParser.ValueContext ctx) {
             // break, continue
             if (expr.equals("break")) {
                 // verify we're in a "for" loop that hasn't ended yet...
-                if (!areWeCurrentlyInAForLoop()) {
-                    throw new ParserRuntimeException(sourceRef, "@break used outside @for loop", null);
+                if (!areWeCurrentlyInAForLoop() && !areWeCurrentlyInASwitchBlock()) {
+                    throw new ParserRuntimeException(sourceRef, "@break used outside @for loop OR @switch block", null);
                 }
                 model.getUnits().add(new BreakStatement(sourceRef));
             } else if (expr.equals("continue")) {

rocker-test-template/src/test/java/com/fizzed/rocker/compiler/CompiledTemplateTest.java

@@ -1200,4 +1200,51 @@ public void withBlockElse8() throws Exception {
         assertThat(html, is("b"));
     }
 
+    @Test
+    public void statementBlock() throws Exception {
+        String html = new rocker8.SwitchStatement()
+            .i(1)
+            .render()
+            .toString()
+            .trim();
+
+        assertThat(html, is("in 1"));
+
+        // case 2 should flow thru 2 & 3
+        html = new rocker8.SwitchStatement()
+            .i(2)
+            .render()
+            .toString()
+            .trim();
+
+        assertThat(html, is("in 2in 3"));
+
+        // case 3
+        html = new rocker8.SwitchStatement()
+            .i(3)
+            .render()
+            .toString()
+            .trim();
+
+        assertThat(html, is("in 3"));
+
+        // case 4 will flow thru to default too
+        html = new rocker8.SwitchStatement()
+            .i(4)
+            .render()
+            .toString()
+            .trim();
+
+        assertThat(html, is("in 4in default"));
+
+        // case 10 is only default
+        html = new rocker8.SwitchStatement()
+            .i(10)
+            .render()
+            .toString()
+            .trim();
+
+        assertThat(html, is("in default"));
+    }
+
 }

rocker-test-template/src/test/java/rocker8/SwitchStatement.rocker.html

@@ -0,0 +1,8 @@
+@args(int i)
+@switch (i) {
+  case (1) {in 1@break}
+  case (2) {in 2}
+  case (3) {in 3@break}
+  case (4) {in 4}
+  default {in default}
+}