rearrange builtins

builtins/input.go

@@ -0,0 +1,32 @@
+package builtins
+
+import "monkey/object"
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+)
+
+// Input ...
+func Input(args ...object.Object) object.Object {
+	if len(args) > 0 {
+		obj, ok := args[0].(*object.String)
+		if !ok {
+			return newError(
+				"argument to `input` not supported, got %s",
+				args[0].Type(),
+			)
+		}
+		fmt.Fprintf(os.Stdout, obj.Value)
+	}
+
+	buffer := bufio.NewReader(os.Stdin)
+
+	line, _, err := buffer.ReadLine()
+	if err != nil && err != io.EOF {
+		return newError(fmt.Sprintf("error reading input from stdin: %s", err))
+	}
+	return &object.String{Value: string(line)}
+}