@ -114,7 +114,7 @@ unsafe impl Trace for FunctionFlags {
/// FunctionBody is specific to this interpreter, it will either be Rust code or JavaScript code (AST Node)
///
/// <https://tc39.es/ecma262/#sec-ecmascript-function-objects>
#[ derive(Trace, Finalize) ]
#[ derive(Clone, Trace, Finalize) ]
pub enum Function {
Native {
function : BuiltInFunction ,
@ -373,6 +373,83 @@ impl BuiltInFunctionObject {
// TODO?: 5. PrepareForTailCall
context . call ( this , this_arg , & arg_list )
}
#[ allow(clippy::wrong_self_convention) ]
fn to_string ( this : & JsValue , _ : & [ JsValue ] , context : & mut Context ) -> JsResult < JsValue > {
let name = {
// Is there a case here where if there is no name field on a value
// name should default to None? Do all functions have names set?
let value = this . get_field ( "name" , & mut * context ) ? ;
if value . is_null_or_undefined ( ) {
None
} else {
Some ( value . to_string ( context ) ? )
}
} ;
let function = {
let object = this
. as_object ( )
. map ( | object | object . borrow ( ) . as_function ( ) . cloned ( ) ) ;
if let Some ( Some ( function ) ) = object {
function
} else {
return context . throw_type_error ( "Not a function" ) ;
}
} ;
match ( & function , name ) {
(
Function ::Native {
function : _ ,
constructable : _ ,
} ,
Some ( name ) ,
) = > Ok ( format! ( "function {}() {{\n [native Code]\n}}" , & name ) . into ( ) ) ,
( Function ::Ordinary { body , params , .. } , Some ( name ) ) = > {
let arguments : String = params
. iter ( )
. map ( | param | param . name ( ) )
. collect ::< Vec < & str > > ( )
. join ( ", " ) ;
let statement_list = & * body ;
// This is a kluge. The implementaion in browser seems to suggest that
// the value here is printed exactly as defined in source. I'm not sure if
// that's possible here, but for now here's a dumb heuristic that prints functions
let is_multiline = {
let value = statement_list . to_string ( ) ;
value . lines ( ) . count ( ) > 1
} ;
if is_multiline {
Ok (
// ?? For some reason statement_list string implementation
// sticks a \n at the end no matter what
format! (
"{}({}) {{\n{}}}" ,
& name ,
arguments ,
statement_list . to_string ( )
)
. into ( ) ,
)
} else {
Ok ( format! (
"{}({}) {{{}}}" ,
& name ,
arguments ,
// The trim here is to remove a \n stuck at the end
// of the statement_list to_string method
statement_list . to_string ( ) . trim ( )
)
. into ( ) )
}
}
_ = > Ok ( "TODO" . into ( ) ) ,
}
}
}
impl BuiltIn for BuiltInFunctionObject {
@ -401,6 +478,7 @@ impl BuiltIn for BuiltInFunctionObject {
. length ( Self ::LENGTH )
. method ( Self ::call , "call" , 1 )
. method ( Self ::apply , "apply" , 1 )
. method ( Self ::to_string , "toString" , 0 )
. build ( ) ;
( Self ::NAME , function_object . into ( ) , Self ::attribute ( ) )