add af_print macro

Fixes #63

Author: 9prady9

examples/helloworld.rs

@@ -1,3 +1,4 @@
+#[macro_use(af_print)]
 extern crate arrayfire as af;
 
 use af::*;
@@ -14,12 +15,11 @@ fn main() {
 
     let dims = Dim4::new(&[num_rows, num_cols, 1, 1]);
 
-    println!("Create a 5-by-3 matrix of random floats on the GPU");
     let a = match randu::<f32>(dims) {
         Ok(value) => value,
         Err(error) => panic!("{}", error),
     };
-    print(&a);
+    af_print!("Create a 5-by-3 matrix of random floats on the GPU", a);
 
     println!("Element-wise arithmetic");
     let  b = sin(&a)
@@ -34,17 +34,17 @@ fn main() {
         .unwrap();
 
     let b3 = ! &a;
-    println!("sin(a) + 1.5 => "); print(&b);
-    println!("sin(a) + cos(a) => "); print(&b2);
-    println!("!a => "); print(&b3);
+    af_print!("sin(a) + 1.5 => ", b);
+    af_print!("sin(a) + cos(a) => ", b2);
+    af_print!("!a => ", b3);
 
     let test = &a + &b;
-    println!("a + b"); print(&test);
+    af_print!("a + b", test);
 
     // Index array using sequences
     let seqs = &[Seq::new(1u32, 3, 1), Seq::default()];
     let sub = index(&a, seqs).unwrap();
-    println!("a(seq(1,3,1), span)"); print(&sub);
+    af_print!("a(seq(1,3,1), span)", sub);
 
     //Index array using array and sequence
     let seq4gen = Seq::new(0u32, 2, 1);
@@ -57,7 +57,7 @@ fn main() {
     idxrs.set_index(&seq4gen, 1, Some(false));
 
     let sub2 = index_gen(&a, idxrs).unwrap();
-    println!("a(indices, seq(0, 2, 1))"); print(&sub2);
+    af_print!("a(indices, seq(0, 2, 1))", sub2);
 
     // printf("Negate the first three elements of second column\n");
     // B(seq(0, 2), 1) = B(seq(0, 2), 1) * -1;
@@ -71,17 +71,16 @@ fn main() {
     print(&row(&a, num_rows - 1).unwrap());
     print(&col(&a, num_cols - 1).unwrap());
 
-    println!("Set last row to 1's");
     let r_dims = Dim4::new(&[3, 1, 1, 1]);
     let r_input: [f32; 3] = [1.0, 1.0, 1.0];
     let r = Array::new(&r_input, r_dims).unwrap();
-    print(&set_row(&a, &r, num_rows - 1).unwrap());
+    let ur = set_row(&a, &r, num_rows - 1).unwrap();
+    af_print!("Set last row to 1's", ur);
 
-    println!("Create 2-by-3 matrix from host data");
     let d_dims = Dim4::new(&[2, 3, 1, 1]);
     let d_input: [i32; 6] = [1, 2, 3, 4, 5, 6];
-    let d = &Array::new(&d_input, d_dims).unwrap();
-    print(d);
+    let d = Array::new(&d_input, d_dims).unwrap();
+    af_print!("Create 2-by-3 matrix from host data", d);
 
     // printf("Copy last column onto first\n");
     // D.col(0) = D.col(end);
@@ -95,8 +94,7 @@ fn main() {
             print(&x.1);
         });
 
-    println!("u8 constant array");
     let u8_cnst = &constant(1 as u8, dims).unwrap();
-    print(u8_cnst);
+    af_print!("u8 constant array", u8_cnst);
     println!("Is u8_cnst array float precision type ? {}", u8_cnst.is_single().unwrap());
 }

src/macros.rs

@@ -103,3 +103,31 @@ macro_rules! join_many {
         }
     };
 }
+
+/// Print given message before printing out the Array to standard output
+///
+/// # Examples
+///
+/// ```
+/// # #[macro_use] extern crate arrayfire;
+///
+/// # fn main() {
+///     use arrayfire::{Dim4, print, randu};
+///     let dims = Dim4::new(&[3, 1, 1, 1]);
+///     let a = match randu::<f32>(dims) {
+///         Ok(value) => value,
+///         Err(error) => panic!("{}", error),
+///     };
+///     af_print!("Create a 5-by-3 matrix of random floats on the GPU", a);
+/// # }
+/// ```
+///
+#[macro_export]
+macro_rules! af_print {
+    [$msg: expr, $x: ident] => {
+        {
+            println!("{}", $msg);
+            print(&$x).unwrap();
+        }
+    };
+}