Add JSON encoding and decoding functions

Include `std::json::encode` and `std::json::decode` in the standard library.

changes/add_json_func.md

@@ -0,0 +1 @@
+* Add `std::json::encode` and `std::json::decode` functions

shesmu-server-ui/src/runtime.ts

@@ -79,6 +79,13 @@ export function dateStartOfDay(date: Date): Date {
     Date.UTC(date.getUTCFullYear(), date.getUTCMonth(), date.getUTCDate())
   );
 }
+export function decodeJson(input: string): any | null {
+  try {
+    return JSON.parse(input);
+  } catch (e) {
+    return null;
+  }
+}
 export function distinct<T>(
   input: T[],
   compare: (left: T, right: T) => boolean

shesmu-server/src/main/java/ca/on/oicr/gsi/shesmu/core/StandardDefinitions.java

@@ -420,6 +420,22 @@ public Imyhat returnType() {
             "$runtime.dictIterator(%s)",
             Imyhat.JSON,
             new FunctionParameter("Map to encode", Imyhat.dictionary(Imyhat.STRING, Imyhat.JSON))),
+        FunctionDefinition.staticMethod(
+            String.join(Parser.NAMESPACE_SEPARATOR, "std", "json", "encode"),
+            RuntimeSupport.class,
+            "encodeJson",
+            "Encodes JSON data as a string",
+            "JSON.stringify(%s)",
+            Imyhat.STRING,
+            new FunctionParameter("Data to encode", Imyhat.JSON)),
+        FunctionDefinition.staticMethod(
+            String.join(Parser.NAMESPACE_SEPARATOR, "std", "json", "decode"),
+            RuntimeSupport.class,
+            "decodeJson",
+            "Decodes JSON data from a string",
+            "$runtime.jsonDecode(%s)",
+            Imyhat.JSON.asOptional(),
+            new FunctionParameter("Data to decode", Imyhat.STRING)),
         FunctionDefinition.virtualMethod(
             String.join(Parser.NAMESPACE_SEPARATOR, "std", "path", "file"),
             "getFileName",

shesmu-server/src/main/java/ca/on/oicr/gsi/shesmu/runtime/RuntimeSupport.java

@@ -152,6 +152,15 @@ public static <T> Tuple collect(Stream<T> items, Function<Stream<T>, Object>...
     return new Tuple(Stream.of(processors).map(p -> p.apply(data.stream())).toArray());
   }
 
+  @RuntimeInterop
+  public static Optional<JsonNode> decodeJson(String input) {
+    try {
+      return Optional.of(MAPPER.readTree(input));
+    } catch (JsonProcessingException e) {
+      return Optional.empty();
+    }
+  }
+
   /** Determine the difference between two instants, in seconds. */
   @RuntimeInterop
   public static long difference(Instant left, Instant right) {
@@ -167,6 +176,15 @@ public static <T> Set<T> difference(Imyhat type, Set<T> left, Set<T> right) {
     return result;
   }
 
+  @RuntimeInterop
+  public static String encodeJson(JsonNode input) {
+    try {
+      return MAPPER.writeValueAsString(input);
+    } catch (JsonProcessingException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
   /**
    * Group items in to outer groups, then apply a complex subgrouping operation to produce subgroups
    * from this input