From 13d9d83383609c3e3174834bc611f21188067195 Mon Sep 17 00:00:00 2001
From: Simon Forman <sforman@hushmail.com>
Date: Sat, 18 Mar 2023 11:31:38 -0700
Subject: [PATCH] pop_list()

Kind of a misnomer, you have to take the tail() of the stack yourself.
This function only returns the list from TOS.
---
 implementations/uvm-ncc/joy.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/implementations/uvm-ncc/joy.c b/implementations/uvm-ncc/joy.c
index 4dff1dd..360cd2b 100644
--- a/implementations/uvm-ncc/joy.c
+++ b/implementations/uvm-ncc/joy.c
@@ -555,8 +555,9 @@ joy_eval(char *symbol, u32 stack, u32 expression)
 	return (u64)stack << 32 | expression;
 }
 
-u64
-swaack(u32 stack, u32 expression)
+
+u32
+pop_list(u32 stack)
 {
 	if (!stack) {
 		error = NOT_ENOUGH_VALUES_ON_STACK;
@@ -567,6 +568,15 @@ swaack(u32 stack, u32 expression)
 		error = NOT_A_LIST;
 		return 0;
 	}
+	return list;
+}
+
+
+u64
+swaack(u32 stack, u32 expression)
+{
+	u32 list = pop_list(stack);
+	CHECK_ERROR
 	stack = cons(tail(stack), list);
 	CHECK_ERROR
 	return (u64)stack << 32 | expression;