Add builtin resolve; change Repr of BuiltinFn.

eval/builtin_func.go

@@ -36,7 +36,7 @@ func (*BuiltinFn) Kind() string {
 }
 
 func (b *BuiltinFn) Repr(int) string {
-	return "$" + FnPrefix + b.Name
+	return "<builtin " + b.Name + ">"
 }
 
 // Call calls a builtin function.
@@ -103,6 +103,8 @@ func init() {
 		&BuiltinFn{"!=", WrapFn(noteq)},
 		&BuiltinFn{"deepeq", deepeq},
 
+		&BuiltinFn{"resolve", WrapFn(resolveFn)},
+
 		&BuiltinFn{"take", WrapFn(take)},
 
 		&BuiltinFn{"count", count},
@@ -713,6 +715,11 @@ func deepeq(ec *EvalCtx, args []Value) {
 	out <- Bool(true)
 }
 
+func resolveFn(ec *EvalCtx, cmd String) {
+	out := ec.ports[1].Chan
+	out <- resolve(string(cmd), ec)
+}
+
 func take(ec *EvalCtx, n int, iterate func(func(Value))) {
 	out := ec.ports[1].Chan
 

eval/external_cmd.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"syscall"
 
+	"github.com/elves/elvish/parse"
 	"github.com/elves/elvish/util"
 )
 
@@ -25,7 +26,7 @@ func (ExternalCmd) Kind() string {
 }
 
 func (e ExternalCmd) Repr(int) string {
-	return "<external " + e.Name + " >"
+	return "<external " + parse.Quote(e.Name) + ">"
 }
 
 // Call calls an external command.

eval/string.go

@@ -27,12 +27,12 @@ func (s String) Call(ec *EvalCtx, args []Value) {
 	resolve(string(s), ec).Call(ec, args)
 }
 
-func resolve(s string, ec *EvalCtx) Fn {
+func resolve(s string, ec *EvalCtx) FnValue {
 	// Try variable
 	splice, ns, name := ParseVariable(string(s))
 	if !splice {
 		if v := ec.ResolveVar(ns, FnPrefix+name); v != nil {
-			if caller, ok := v.Get().(Fn); ok {
+			if caller, ok := v.Get().(FnValue); ok {
 				return caller
 			}
 		}