Allow comments in JSON parsing

Author: mikera

convex-core/src/main/antlr4/convex/core/json/reader/antlr/JSON.g4

@@ -80,6 +80,16 @@ fragment EXP
     : [Ee] [+-]? [0-9]+
     ;
 
+// Multi-line comments (ignored)
+MULTILINE_COMMENT
+	: '/*' .* '*/' -> skip
+	;
+
+// Single-line comments (ignored)
+SINGLELINE_COMMENT
+	: '//' ~[\r\n]* -> skip
+	;
+
 WS
     : [ \t\n\r]+ -> skip
     ;

convex-core/src/test/java/convex/core/utils/JSONUtilsTest.java

@@ -122,6 +122,18 @@ public void testJSON() {
 		assertEquals(Maps.of("[\"\" 3]",4), RT.cvm(JSONUtils.json(Maps.of(Vectors.of("",3),4))));
 	}
 
+	@Test
+	public void testJSONComments() {
+		assertEquals(Vectors.of(true,null),JSONUtils.parse("[true, /* \n */ null]"));
+		assertEquals(RT.cvm(12),JSONUtils.parse("12 //foo"));
+		assertEquals(RT.cvm(12),JSONUtils.parse("//foo \n 12"));
+		assertEquals(RT.cvm(12),JSONUtils.parse("//foo /* \n 12"));
+
+		assertThrows(ParseException.class,()->JSONUtils.parse("/* 67")); // comment not closed
+		assertThrows(ParseException.class,()->JSONUtils.parse("//")); // no value
+		
+	}
+	
 	@Test
 	public void testJSONRoundTrips() {
 

convex-java/src/main/java/convex/java/JSON.java

@@ -9,7 +9,6 @@
 import java.util.Map;
 
 import org.json.simple.JSONObject;
-import org.json.simple.JSONValue;
 import org.json.simple.parser.JSONParser;
 import org.json.simple.parser.ParseException;