add initial toString block (#1958)

docs/reference/text/to-string.md

@@ -0,0 +1,7 @@
+# to string
+
+Converts a value into a text representation.
+
+```sig
+toString(123)
+```

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

@@ -549,5 +549,7 @@
   "serial.writeString": "Send a piece of text through the serial connection.",
   "serial.writeValue": "Write a name:value pair as a line to the serial port.",
   "serial.writeValue|param|name": "name of the value stream, eg: x",
-  "serial.writeValue|param|value": "to write"
+  "serial.writeValue|param|value": "to write",
+  "toString": "Convert any value to a string",
+  "toString|param|value": "value to be converted to a string"
 }

libs/core/_locales/core-strings.json

@@ -371,6 +371,7 @@
   "serial.writeString|block": "serial|write string %text",
   "serial.writeValue|block": "serial|write value %name|= %value",
   "serial|block": "serial",
+  "toString|block": "convert $value=variables_get(myValue) to string",
   "{id:category}AnalogInPin": "AnalogInPin",
   "{id:category}AnalogOutPin": "AnalogOutPin",
   "{id:category}Array": "Array",

libs/core/control.ts

@@ -53,3 +53,14 @@ namespace control {
     //% shim=pxtrt::runtimeWarning
     export function runtimeWarning(message: string) { }
 }
+
+/**
+ * Convert any value to a string
+ * @param value value to be converted to a string
+ */
+//% help=text/to-string weight=1
+//% block="convert $value=variables_get(myValue) to string"
+//% blockId=variable_to_string blockNamespace="text"
+function toString(value: any): string {
+    return "" + value;
+}