Add some utility methods to Value

src/value.rs

@@ -36,27 +36,17 @@ impl<'a> Value<'a> {
         }
     }
 
-    pub fn as_userdata(&self) -> crate::Result<&AnyUserdata<'a>> {
+    pub fn as_number(&self) -> crate::Result<f64> {
         match self {
-            Value::Userdata(ud) => Ok(ud),
+            Value::Number(v) => Ok(*v),
             _ => {
-                Err(crate::Error::UnexpectedType("Userdata".to_string(), self.type_name().to_string()))
+                Err(crate::Error::UnexpectedType("Number".to_string(), self.type_name().to_string()))
-            }
-        }
-    }
-
-    /// Consumes self, and attempts to get `AnyUserdata`.
-    /// 
-    /// Returns an error if this value is not userdata
-    pub fn into_userdata(self) -> crate::Result<AnyUserdata<'a>> {
-        match self {
-            Value::Userdata(ud) => Ok(ud),
-            _ => {
-                Err(crate::Error::UnexpectedType("Userdata".to_string(), self.type_name().to_string()))
             }
         }
     }
 
+    /// If `self` is an instance of Value::String, returns a borrow to it. If it is not then
+    /// an `UnexpectedType` error is returned.
     pub fn as_string(&self) -> crate::Result<&String> {
         match self {
             Value::String(s) => Ok(s),
@@ -66,6 +56,41 @@ impl<'a> Value<'a> {
         }
     }
 
+    /// If `self` is an instance of Value::Function, returns a borrow to it. If it is not then
+    /// an `UnexpectedType` error is returned.
+    pub fn as_function(&self) -> crate::Result<Function> {
+        match self {
+            Value::Function(v) => Ok(v.clone()),
+            _ => {
+                Err(crate::Error::UnexpectedType("Table".to_string(), self.type_name().to_string()))
+            }
+        }
+    }
+
+    /// If `self` is an instance of Value::Table, returns a borrow to it. If it is not then
+    /// an `UnexpectedType` error is returned.
+    pub fn as_table(&self) -> crate::Result<Table> {
+        match self {
+            Value::Table(v) => Ok(v.clone()),
+            _ => {
+                Err(crate::Error::UnexpectedType("Table".to_string(), self.type_name().to_string()))
+            }
+        }
+    }
+
+    /// If `self` is an instance of Value::Userdata, returns a borrow to it. If it is not then
+    /// an `UnexpectedType` error is returned.
+    pub fn as_userdata(&self) -> crate::Result<AnyUserdata<'a>> {
+        match self {
+            Value::Userdata(ud) => Ok(ud.clone()),
+            _ => {
+                Err(crate::Error::UnexpectedType("Userdata".to_string(), self.type_name().to_string()))
+            }
+        }
+    }
+
+    /// If `self` is an instance of Value::String, the string is returned. If it is not then
+    /// an `UnexpectedType` error is returned.
     pub fn into_string(self) -> crate::Result<String> {
         match self {
             Value::String(s) => Ok(s),
@@ -75,6 +100,19 @@ impl<'a> Value<'a> {
         }
     }
 
+    /// If `self` is an instance of Value::Function, the function is returned. If it is not then
+    /// an `UnexpectedType` error is returned.
+    pub fn into_function(self) -> crate::Result<Function<'a>> {
+        match self {
+            Value::Function(v) => Ok(v),
+            _ => {
+                Err(crate::Error::UnexpectedType("Function".to_string(), self.type_name().to_string()))
+            }
+        }
+    }
+
+    /// If `self` is an instance of Value::Table, the table is returned. If it is not then
+    /// an `UnexpectedType` error is returned.
     pub fn into_table(self) -> crate::Result<Table<'a>> {
         match self {
             Value::Table(v) => Ok(v),
@@ -84,11 +122,13 @@ impl<'a> Value<'a> {
         }
     }
 
-    pub fn into_function(self) -> crate::Result<Function<'a>> {
+    /// If `self` is an instance of Value::Userdata, the userdata is returned. If it is not then
+    /// an `UnexpectedType` error is returned.
+    pub fn into_userdata(self) -> crate::Result<AnyUserdata<'a>> {
         match self {
-            Value::Function(v) => Ok(v),
+            Value::Userdata(ud) => Ok(ud),
             _ => {
-                Err(crate::Error::UnexpectedType("Function".to_string(), self.type_name().to_string()))
+                Err(crate::Error::UnexpectedType("Userdata".to_string(), self.type_name().to_string()))
             }
         }
     }