import entries builder

src/builder/import.rs

@@ -1,11 +1,17 @@
 use super::invoke::{Invoke, Identity};
 use elements;
 
-pub struct ImportBuilder<F: Identity> {
+pub struct ImportBuilder<F=Identity> {
     callback: F,
     module: String,
     field: String,
-    binding: ExternalBinding,
+    binding: elements::External,
+}
+
+impl ImportBuilder {
+    pub fn new() -> Self {
+        ImportBuilder::with_callback(Identity)
+    }
 }
 
 impl<F> ImportBuilder<F> {
@@ -13,27 +19,97 @@ impl<F> ImportBuilder<F> {
     pub fn with_callback(callback: F) -> Self {
         ImportBuilder {
             callback: callback,
-            module
+            module: String::new(),
+            field: String::new(),
+            binding: elements::External::Function(0),
         }
     }
 
+    pub fn module(mut self, name: &str) -> Self {
+        self.module = name.to_owned();
+        self
+    }
+
+    pub fn field(mut self, name: &str) -> Self {
+        self.field = name.to_owned();
+        self
+    }
+
+    pub fn path(self, module: &str, field: &str) -> Self {
+        self.module(module).field(field)
+    }
+
+    pub fn with_external(mut self, external: elements::External) -> Self {
+        self.binding = external;
+        self
+    }
+
     pub fn external(self) -> ImportExternalBuilder<Self> {
+        ImportExternalBuilder::with_callback(self)
+    }
+}
 
+impl<F> ImportBuilder<F> where F: Invoke<elements::ImportEntry> {
+    pub fn build(self) -> F::Result {
+        self.callback.invoke(elements::ImportEntry::new(self.module, self.field, self.binding))
+    }
+}
+
+impl<F> Invoke<elements::External> for ImportBuilder<F> {
+    type Result = Self;
+    fn invoke(self, val: elements::External) -> Self {
+        self.with_external(val)
     }
 }
 
 pub struct ImportExternalBuilder<F=Identity> {
     callback: F,
-    binding: ExternalBinding,
+    binding: elements::External,
 }
 
-impl<F> ImportExternalBuilder<F> where F: Invoke<ExternalBinding> {
-    pub fn with_callback(callback: F) {
+impl<F> ImportExternalBuilder<F> where F: Invoke<elements::External> {
+    pub fn with_callback(callback: F) -> Self {
         ImportExternalBuilder{
             callback: callback,
-            binding: ExternalBinding::ExistingFunc(0),
+            binding: elements::External::Function(0),
         }
     }
 
-    pub fn 
+    pub fn func(mut self, index: u32) -> F::Result {
+        self.binding = elements::External::Function(index);
+        self.callback.invoke(self.binding)
+    }
+
+    pub fn memory(mut self, min: u32, max: Option<u32>) -> F::Result {
+        self.binding = elements::External::Memory(elements::MemoryType::new(min, max));
+        self.callback.invoke(self.binding)
+    }
+
+    pub fn table(mut self, min: u32, max: Option<u32>) -> F::Result {
+        self.binding = elements::External::Table(elements::TableType::new(min, max));
+        self.callback.invoke(self.binding)
+    }
+
+    pub fn global(mut self, value_type: elements::ValueType, is_mut: bool) -> F::Result {
+        self.binding = elements::External::Global(elements::GlobalType::new(value_type, is_mut));
+        self.callback.invoke(self.binding)
+    }
+}
+
+/// New builder for import entry
+pub fn import() -> ImportBuilder {
+    ImportBuilder::new()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::import;
+
+    #[test]
+    fn example() {
+        let entry = import().module("env").field("memory").external().memory(256, Some(256)).build();
+
+        assert_eq!(entry.module(), "env");
+        assert_eq!(entry.field(), "memory");
+    }
 }

src/builder/mod.rs

@@ -4,6 +4,8 @@ mod invoke;
 mod module;
 mod code;
 mod misc;
+mod import;
 
 pub use self::module::{module, ModuleBuilder};
 pub use self::code::signatures;
+pub use self::import::import;

src/elements/import_entry.rs

@@ -11,8 +11,17 @@ pub struct GlobalType {
 }
 
 impl GlobalType {
+    /// New global type
+    pub fn new(content_type: ValueType, is_mutable: bool) -> Self {
+        GlobalType {
+            content_type: content_type,
+            is_mutable: is_mutable,
+        }
+    }
+
     /// Type of the global entry
     pub fn content_type(&self) -> ValueType { self.content_type }
+
     /// Is global entry is declared as mutable
     pub fn is_mutable(&self) -> bool { self.is_mutable }
 }
@@ -47,6 +56,13 @@ pub struct TableType {
 }
 
 impl TableType {
+    /// New table definition
+    pub fn new(min: u32, max: Option<u32>) -> Self {
+        TableType {
+            elem_type: 0,
+            limits: ResizableLimits::new(min, max),
+        }
+    }
     /// Table memory specification
     pub fn limits(&self) -> &ResizableLimits { &self.limits }
 }
@@ -81,6 +97,13 @@ pub struct ResizableLimits {
 }
 
 impl ResizableLimits {
+    /// New memory limits definition
+    pub fn new(min: u32, max: Option<u32>) -> Self {
+        ResizableLimits {
+            initial: min,
+            maximum: max,
+        }
+    }
     /// Initial size
     pub fn initial(&self) -> u32 { self.initial }
     /// Maximum size
@@ -124,6 +147,10 @@ impl Serialize for ResizableLimits {
 pub struct MemoryType(ResizableLimits);
 
 impl MemoryType {
+    /// New memory definition
+    pub fn new(min: u32, max: Option<u32>) -> Self {
+        MemoryType(ResizableLimits::new(min, max))
+    }
     /// Limits of the memory entry.
     pub fn limits(&self) -> &ResizableLimits {
         &self.0

src/elements/mod.rs

@@ -1,4 +1,4 @@
-//! Elemets of the WebAssembly binary format.
+//! Elements of the WebAssembly binary format.
 
 use std::io;