Adding a Json BNF and use-case

.github/workflows/maven.yml

@@ -0,0 +1,27 @@
+# This workflow will build a Java project with Maven
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
+
+name: Java CI with Maven
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+    - name: Cache Maven packages
+      uses: actions/cache@v1
+      with:
+        path: ~/.m2
+        key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+        restore-keys: ${{ runner.os }}-m2    
+    - name: Build with Maven
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}      
+      run: mvn -B compile --file pom.xml

.gitignore

@@ -100,7 +100,6 @@ $.*
 texput.*
 Untitled*
 .~lock.*
-_*
 
 # Prefixes // vim: +,/^\s*$/-1!sort -u
 a.out
@@ -148,3 +147,10 @@ out/
 .classpath
 .project
 .settings/
+
+# MacOS junk
+.DS_Store
+
+# IntelliJunk
+.idea/
+.iml

pom.xml

@@ -88,4 +88,4 @@
 			</plugin>
 		</plugins>
 	</build>
-</project>
+</project>

src/test/java/il/ac/technion/cs/fling/examples/LoopOverLanguageDefinitions.java

@@ -27,6 +27,7 @@
       new RegularExpression(), //
       new HTMLTable(), //
       new SimpleArithmetic(), //
+      new Json(),
   };
   private static final Map<String, String> files = ((Supplier<Map<String, String>>) () -> {
     final Map<String, String> $ = new LinkedHashMap<>();

src/test/java/il/ac/technion/cs/fling/examples/languages/Json.java

@@ -0,0 +1,45 @@
+package il.ac.technion.cs.fling.examples.languages;
+
+import il.ac.technion.cs.fling.BNF;
+import il.ac.technion.cs.fling.Terminal;
+import il.ac.technion.cs.fling.Variable;
+import il.ac.technion.cs.fling.examples.FluentLanguageAPI;
+import il.ac.technion.cs.fling.examples.languages.Json.V;
+import il.ac.technion.cs.fling.examples.languages.Json.Σ;
+
+import static il.ac.technion.cs.fling.Symbol.noneOrMore;
+import static il.ac.technion.cs.fling.examples.languages.Json.V.*;
+import static il.ac.technion.cs.fling.examples.languages.Json.Σ.*;
+import static il.ac.technion.cs.fling.grammars.api.BNFAPI.bnf;
+
+@SuppressWarnings("NonAsciiCharacters")
+public class Json implements FluentLanguageAPI<Σ, V> {
+  public enum Σ implements Terminal {
+    array, end, isSetTo, key, object, value, _null_
+  }
+
+  public enum V implements Variable {
+    Element, Field, Json, Value
+  }
+
+  @Override public Class<Σ> Σ() {
+    return Σ.class;
+  }
+  @Override public Class<V> V() {
+    return V.class;
+  }
+  @Override public BNF BNF() {
+    return bnf().
+        start(Json).
+        derive(Json).to(Element).
+        derive(Element).to(object, noneOrMore(Field), end).
+            or(array, noneOrMore(Element), end).
+            or(Value).
+        derive(Value).to(value.with(String.class)).
+            or(value.with(Number.class)).
+            or(value.with(Boolean.class)).
+            or(_null_).
+        derive(Field).to(key.with(String.class), isSetTo, Element).
+        build();
+  }
+}

src/test/java/il/ac/technion/cs/fling/examples/usecases/Json.java

@@ -0,0 +1,44 @@
+package il.ac.technion.cs.fling.examples.usecases;
+
+import static il.ac.technion.cs.fling.examples.generated.Json.value;
+import static il.ac.technion.cs.fling.examples.generated.Json.array;
+import static il.ac.technion.cs.fling.examples.generated.Json.object;
+
+// @formatter:off
+public class Json {
+  public static void main(String[] args) {
+    value("f");
+    value(8);
+    value(true);
+    array(); //TODO: how come this is legal?
+    array().end();
+    array().value("f").end();
+    array()
+            .value(8)
+            .value("fg")
+            .array().end()
+    .end();
+
+    object().end();
+
+    object().key("name").isSetTo().value(8).end();
+
+    object()
+            .key("name").isSetTo().value("Joe")
+            .key("age").isSetTo().value(8)
+    .end();
+
+    object().
+      key("name").isSetTo()
+            .object()
+              .key("first").isSetTo().value("Joe")
+              .key("last").isSetTo()._null_()
+            .end().
+      key("ages").isSetTo()
+            .array()
+              .value(60)
+              .value(70)
+            .end()
+    .end();
+  }
+}