support for wait/when

libs/base/_locales/base-jsdoc-strings.json

@@ -144,6 +144,12 @@
   "loops.pause|param|ms": "how long to pause for, eg: 100, 200, 500, 1000, 2000",
   "loops.timePicker": "Get the time field editor",
   "loops.timePicker|param|ms": "time duration in milliseconds, eg: 500, 1000",
+  "loops.waitUntil": "Busy wait for a condition to be true",
+  "loops.waitUntil|param|condition": "condition to test for",
+  "loops.waitUntil|param|timeOut": "if positive, maximum duration to wait for in milliseconds",
+  "loops.when": "Runs code when the condition becomes true",
+  "loops.when|param|condition": "condition to test",
+  "loops.when|param|handler": "code to run",
   "parseInt": "Convert a string to an integer.",
   "serial": "Reading and writing data over a serial connection.",
   "serial.writeBuffer": "Send a buffer across the serial connection.",

libs/base/pxt.json

@@ -17,7 +17,8 @@
         "control.cpp",
         "control.ts",
         "serial.cpp",
-        "serial.ts"
+        "serial.ts",
+        "loops.ts"
     ],
     "testFiles": [
         "test.ts"