Add parse_json.

src/packages/lang_core.rs

@@ -88,7 +88,6 @@ mod core_functions {
         #[cfg(feature = "f32_float")]
         std::thread::sleep(std::time::Duration::from_secs_f32(seconds));
     }
-
     /// Block the current thread for a particular number of `seconds`.
     #[cfg(not(feature = "no_std"))]
     pub fn sleep(seconds: INT) {
@@ -97,6 +96,23 @@ mod core_functions {
         }
         std::thread::sleep(std::time::Duration::from_secs(seconds as u64));
     }
+
+    /// Parse a JSON string into a value.
+    ///
+    /// # Example
+    ///
+    /// ```rhai
+    /// let m = parse_json(`{"a":1, "b":2, "c":3}`);
+    ///
+    /// print(m);       // prints #{"a":1, "b":2, "c":3}
+    /// ```
+    #[cfg(not(feature = "no_index"))]
+    #[cfg(not(feature = "no_object"))]
+    #[cfg(feature = "metadata")]
+    #[rhai_fn(return_raw)]
+    pub fn parse_json(_ctx: NativeCallContext, json: &str) -> RhaiResultOf<Dynamic> {
+        serde_json::from_str(json).map_err(|err| err.to_string().into())
+    }
 }
 
 #[cfg(not(feature = "no_function"))]

src/packages/map_basic.rs

@@ -2,7 +2,7 @@
 
 use crate::engine::OP_EQUALS;
 use crate::plugin::*;
-use crate::{def_package, format_map_as_json, Dynamic, ImmutableString, Map, RhaiResultOf, INT};
+use crate::{def_package, Dynamic, ImmutableString, Map, NativeCallContext, RhaiResultOf, INT};
 #[cfg(feature = "no_std")]
 use std::prelude::v1::*;
 
@@ -304,6 +304,9 @@ mod map_functions {
     /// print(m.to_json());     // prints {"a":1, "b":2, "c":3}
     /// ```
     pub fn to_json(map: &mut Map) -> String {
-        format_map_as_json(map)
+        #[cfg(feature = "metadata")]
+        return serde_json::to_string(map).unwrap_or_else(|_| "ERROR".into());
+        #[cfg(not(feature = "metadata"))]
+        return crate::format_map_as_json(map);
     }
 }