examples/web-sys/src/lib.rs

@@ -10,14 +10,20 @@ pub fn main() {
     console_log!("Hello", "there", "world");
 
     // Various types.
+    console_log!("f32", 1f32, "f64", 2f64);
+    console_log!("u8", 3u8, "i8", 4i8);
+    console_log!("u16", 5u16, "i16", 6i16);
+    console_log!("u32", 7u32, "i32", 8i8);
+    //console_log!("u64", 9u64, "i64", 10i64);
+    console_log!("usize", 11usize, "isize", 12isize);
+
+    // More types.
     console_log!(
-        1.0,
-        2f64,
         true,
         "&str",
         String::from("owned string"),
         Some("an option"),
-        None as Option<i32>,
+        (None as Option<i32>),
     );
 
     // Various levels.

src/console/web_sys.rs

@@ -3,6 +3,73 @@ pub use ::wasm_bindgen;
 #[doc(hidden)]
 pub use ::web_sys;
 
+use ::wasm_bindgen::JsValue;
+
+pub struct ConsoleArg(JsValue);
+
+impl ConsoleArg {
+    pub fn into_inner(self) -> JsValue {
+        self.0
+    }
+}
+
+use crate::ToConsole;
+
+macro_rules! into_jsvalue {
+    ($($n:ident),*) => ($(
+        impl ToConsole for $n {
+            #[inline]
+            fn to_console(self) -> ConsoleArg {
+                ConsoleArg(self.into())
+            }
+        }
+    )*)
+}
+
+// TODO u64 and f64?
+// TODO: impl<'a, T> From<&'a T> for JsValue where T: JsCast ?
+
+into_jsvalue!(bool, f32, f64, i8, i16, i32, u8, u16, u32, String);
+
+impl<'a> ToConsole for &'a String {
+    fn to_console(self) -> ConsoleArg {
+        ConsoleArg(self.into())
+    }
+}
+
+impl<'a> ToConsole for &'a str {
+    fn to_console(self) -> ConsoleArg {
+        ConsoleArg(self.into())
+    }
+}
+
+impl<T> ToConsole for Option<T>
+where
+    T: ToConsole,
+{
+    fn to_console(self) -> ConsoleArg {
+        match self {
+            Some(s) => s.to_console(),
+            None => ConsoleArg(JsValue::undefined()),
+        }
+    }
+}
+
+impl ToConsole for usize {
+    fn to_console(self) -> ConsoleArg {
+        // usize/isize is always 32-bit in Wasm.
+        // But perhaps this should have a guard of some kind.
+        ConsoleArg((self as u32).into())
+    }
+}
+
+impl ToConsole for isize {
+    fn to_console(self) -> ConsoleArg {
+        // As above.
+        ConsoleArg((self as i32).into())
+    }
+}
+
 // It is necessary to expose these wrapper macros in order to pass the $crate
 // meta-variable to the proc macro. This in turn allows the macros to be
 // re-exported from third-party crates without breakage.

src/lib.rs

@@ -74,12 +74,14 @@
 //! ```toml
 //! weblog = { version = "0.3", default-features = false, features = ["stdweb"] }
 //! ```
-//!
 
 mod console;
 
-#[cfg(feature = "web_sys")]
+pub trait ToConsole {
-pub use self::console::web_sys::*;
+    fn to_console(self) -> ConsoleArg;
+}
 
 #[cfg(feature = "std_web")]
 pub use self::console::std_web::*;
+#[cfg(feature = "web_sys")]
+pub use self::console::web_sys::*;

weblog-proc-macro/src/lib.rs

@@ -16,7 +16,7 @@ pub fn console_assert(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("assert_with_condition_and_data", 1),
-        iter::once(ArgMode::PassThrough).chain(iter::repeat(ArgMode::IntoJsValue)),
+        iter::once(ArgMode::PassThrough).chain(iter::repeat(ArgMode::Console)),
         crate_name,
         args,
     )
@@ -80,7 +80,7 @@ pub fn console_debug(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("debug", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -93,7 +93,7 @@ pub fn console_dir(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("dir", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -106,7 +106,7 @@ pub fn console_dirxml(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("dirxml", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -119,7 +119,7 @@ pub fn console_error(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("error", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -132,7 +132,7 @@ pub fn console_exception(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("exception", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -145,7 +145,7 @@ pub fn console_info(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("info", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -158,7 +158,7 @@ pub fn console_log(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("log", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -171,7 +171,7 @@ pub fn console_table(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("table", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -222,7 +222,7 @@ pub fn console_time_log(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("time_log_with_label_and_data", 1),
-        iter::once(ArgMode::PassThrough).chain(iter::repeat(ArgMode::IntoJsValue)),
+        iter::once(ArgMode::PassThrough).chain(iter::repeat(ArgMode::Console)),
         crate_name,
         args,
     )
@@ -241,7 +241,7 @@ pub fn console_time_stamp(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::fixed(name, 1),
-        iter::once(ArgMode::IntoJsValue),
+        iter::once(ArgMode::Console),
         crate_name,
         args,
     )
@@ -254,7 +254,7 @@ pub fn console_trace(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("trace", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )
@@ -267,7 +267,7 @@ pub fn console_warn(input: TokenStream) -> TokenStream {
 
     quote_console_func(
         ConsoleFunc::variadic("warn", 0),
-        iter::repeat(ArgMode::IntoJsValue),
+        iter::repeat(ArgMode::Console),
         crate_name,
         args,
     )

weblog-proc-macro/src/weblog_impl.rs

@@ -32,7 +32,7 @@ pub fn quote_console_func(
 ) -> TokenStream {
     let mut out_args = in_args
         .iter()
-        .map(|arg| quote_arg(&crate_name, arg, arg_modes.next().unwrap_or_default()));
+        .map(|arg| quote_arg(arg, arg_modes.next().unwrap_or_default()));
 
     let num_provided = out_args.len();
     let num_fixed = cmp::min(num_provided, params_fixed);
@@ -68,14 +68,15 @@ pub fn quote_console_func(
     (quote! { #crate_name::web_sys::console::#ident(#args) }).into()
 }
 
-fn quote_arg(crate_name: &Ident, arg: &Expr, arg_mode: ArgMode) -> TokenStream2 {
+#[inline]
+fn quote_arg(arg: &Expr, arg_mode: ArgMode) -> TokenStream2 {
     match arg_mode {
         ArgMode::PassThrough => {
             quote! { #arg }
         }
-        ArgMode::IntoJsValue => {
+        ArgMode::Console => {
             quote! {
-                &::std::convert::Into::<#crate_name::wasm_bindgen::JsValue>::into(#arg)
+                &#arg.to_console().into_inner()
             }
         }
     }
@@ -111,7 +112,7 @@ impl ConsoleFunc {
 #[derive(Debug, Copy, Clone)]
 pub enum ArgMode {
     PassThrough,
-    IntoJsValue,
+    Console,
 }
 
 impl Default for ArgMode {