Merge #15

15: Enhance `Wasmer::XxxArray` r=Hywan a=irxground

ref: #14
Now `Wasmer::XxxArray` has `each` method and include `Enumerable` module.

> The Enumerable mixin provides collection classes with several traversal and searching methods, and with the ability to sort. The class must provide a method each, which yields successive members of the collection.
https://docs.ruby-lang.org/en/2.6.0/Enumerable.html


Co-authored-by: irxground <irxnjhtchlnrw@gmail.com>

src/lib.rs

@@ -104,7 +104,11 @@ pub extern "C" fn Init_wasmer() {
 
                     // Declare the `[]` (get) method.
                     itself.def("[]", memory::view::$mod_name::ruby_memory_view_get);
-                });
+
+                    // Declare the `each` method.
+                    itself.def("each", memory::view::$mod_name::ruby_memory_view_each);
+                })
+                .include("Enumerable");
         };
     }
 

src/memory/view.rs

@@ -9,7 +9,7 @@ macro_rules! memory_view {
             use lazy_static::lazy_static;
             use rutie::{
                 class, methods, wrappable_struct, AnyException, Exception, Fixnum, Integer,
-                NilClass, Object,
+                NilClass, Object, VM,
             };
             use std::{mem::size_of, rc::Rc};
             use wasmer_runtime as runtime;
@@ -71,6 +71,15 @@ macro_rules! memory_view {
                         Ok(view[offset + index].get())
                     }
                 }
+
+                pub fn each(&self) {
+                    let view = self.memory.view::<$wasm_type>();
+
+                    for nth in self.offset..view.len() {
+                        let value = view[nth].get() as i64;
+                        VM::yield_object(Integer::from(value));
+                    }
+                }
             }
 
             wrappable_struct!(MemoryView, MemoryViewWrapper, MEMORY_VIEW_WRAPPER);
@@ -117,6 +126,12 @@ macro_rules! memory_view {
                         ))
                     })
                 }
+
+                fn ruby_memory_view_each() -> RubyMemoryView {
+                    let memory_view = _itself.get_data(&*MEMORY_VIEW_WRAPPER);
+                    memory_view.each();
+                    _itself
+                }
             );
         }
     };

tests/memory_test.rb

@@ -99,20 +99,28 @@ def test_hello_world
     nth = 0
     string = ""
 
-    while true
-      char = memory[nth]
-
-      if 0 == char
-        break
-      end
-
-      string += char.chr
+    memory.each do |char|
+      break if 0 == char
+      string << char.chr
       nth += 1
     end
 
+    assert_equal 13, nth
     assert_equal "Hello, World!", string
   end
 
+  def test_enumerable
+    instance = Wasmer::Instance.new self.bytes
+    memory = instance.memory.int16_view
+    memory[0] = 1
+    memory[1] = 10
+    memory[2] = 100
+    memory[3] = 1000
+    memory[5] = 2
+    sum = memory.take_while{|x| x > 0}.inject(0, &:+)
+    assert_equal 1111, sum
+  end
+
   def test_views_share_the_same_buffer
     instance = Wasmer::Instance.new self.bytes
     int8 = instance.memory.int8_view