FEATURE: multiple array evaluation

* function to set manual evaluation setting
* function to check manual evaluation setting
* multiple array evaluation macro `eval!`

Author: 9prady9

src/array.rs

@@ -63,6 +63,12 @@ extern {
 
     fn af_eval(arr: AfArray) -> c_int;
 
+    fn af_eval_multiple(num: c_int, arrays: *const AfArray) -> c_int;
+
+    fn af_set_manual_eval_flag(flag: c_int) -> c_int;
+
+    fn af_get_manual_eval_flag(flag: *mut c_int) -> c_int;
+
     fn af_retain_array(out: MutAfArray, arr: AfArray) -> c_int;
 
     fn af_copy_array(out: MutAfArray, arr: AfArray) -> c_int;
@@ -385,3 +391,53 @@ pub fn print(input: &Array) {
         HANDLE_ERROR(AfError::from(err_val));
     }
 }
+
+/// evaluate multiple arrays
+///
+/// Use this function to evaluate multiple arrays in single call
+///
+/// # Parameters
+///
+/// - `inputs` are the list of arrays to be evaluated
+pub fn eval_multiple(inputs: Vec<&Array>) {
+    unsafe {
+        let mut v = Vec::new();
+        for i in inputs {
+            v.push(i.get());
+        }
+
+        let err_val = af_eval_multiple(v.len() as c_int, v.as_ptr() as *const AfArray);
+        HANDLE_ERROR(AfError::from(err_val));
+    }
+}
+
+/// Set eval flag value
+///
+/// This function can be used to toggle on/off the manual evaluation of arrays.
+///
+/// # Parameters
+///
+/// - `flag` is a boolean value indicating manual evaluation setting
+pub fn set_manual_eval(flag: bool) {
+    unsafe {
+        let err_val = af_set_manual_eval_flag(flag as c_int);
+        HANDLE_ERROR(AfError::from(err_val));
+    }
+}
+
+/// Get eval flag value
+///
+/// This function can be used to find out if manual evaluation of arrays is
+/// turned on or off.
+///
+/// # Return Values
+///
+/// A boolean indicating manual evaluation setting.
+pub fn is_eval_manual() -> bool {
+    unsafe {
+        let mut ret_val: i32 = 0;
+        let err_val = af_get_manual_eval_flag(&mut ret_val as *mut c_int);
+        HANDLE_ERROR(AfError::from(err_val));
+        ret_val > 0
+    }
+}

src/lib.rs

@@ -6,7 +6,7 @@
 extern crate lazy_static;
 
 pub use array::Array;
-pub use array::{print};
+pub use array::{print, eval_multiple, is_eval_manual, set_manual_eval};
 mod array;
 
 //pub use algorithm::{sum_nan, product_nan, sum_nan_all, product_nan_all};

src/macros.rs

@@ -128,3 +128,17 @@ macro_rules! af_print {
         }
     };
 }
+
+/// Evaluate arbitrary number of arrays
+#[macro_export]
+macro_rules! eval {
+    [$($x:ident),+] => {
+        {
+            let mut temp_vec = Vec::new();
+            $(
+                temp_vec.push($x);
+             )*
+            eval_multiple(temp_vec)
+        }
+    };
+}