From 1456d7073742e39985aa093bdbc152f4f9cd07a4 Mon Sep 17 00:00:00 2001
From: kitty <nepeta@canaglie.net>
Date: Mon, 23 Mar 2026 18:51:19 +1100
Subject: value to +to -to

---
 readme.md    | 15 +++++++++++++++
 sanctuary.fs |  6 ++++++
 2 files changed, 21 insertions(+)

diff --git a/readme.md b/readme.md
index 7d56c69..940eddf 100644
--- a/readme.md
+++ b/readme.md
@@ -71,6 +71,10 @@ add u2 to u1.
 ### `+!   ( a -- )`
 add one to the value at memory address a.
 
+### `+to   ( comp: "name" -- | intr: u "name" -- ) IMMEDIATE`
+compile or execute (depending on `state`) code to add u to the contents
+of a `value`. (in compile mode u is whatever was on the stack already.)
+
 ### `,   ( u -- )`
 write a 64 bit value to user memory and increment the user memory pointer.
 
@@ -80,6 +84,10 @@ subtract u2 from u1.
 ### `-!   ( a -- )`
 subtract one from the value at memory address a.
 
+### `-to   ( comp: "name" -- | intr: u "name" -- ) IMMEDIATE`
+compile or execute (depending on `state`) code to subtract u from the contents
+of a `value`. (in compile mode u is whatever was on the stack already.)
+
 ### `-rot   ( u1 u2 u3 -- u3 u1 u2 )`
 rotate the three topmost values on the stack so that the topmost value
 is moved to the third highest.
@@ -441,6 +449,10 @@ conclude an if statement.
 ### `tib   ( -- a )`
 a variable containing the address of the current input buffer.
 
+### `to   ( comp: "name" -- | intr: u "name" -- ) IMMEDIATE`
+compile or execute (depending on `state`) code to modify the contents
+of a `value`.
+
 ### `true   ( -- u )`
 a cell with all bits set.
 
@@ -450,6 +462,9 @@ write u characters at a to output.
 ### `until   ( ? -- ) IMMEDIATE COMPILE-ONLY`
 if the given flag is true, loop back to `begin`.
 
+### `value   ( u "name" -- )`
+create a value called name, the initial value of which is u.
+
 ### `variable   ( "name" -- )`
 create a variable word, which yields an address that can be written and read.
 
diff --git a/sanctuary.fs b/sanctuary.fs
index ff4a266..6bdfbfc 100644
--- a/sanctuary.fs
+++ b/sanctuary.fs
@@ -44,6 +44,12 @@
 : constant  create , does> @ ;
 : variable  create 1 cells allot ;
 
+: value  parse-name (header) latest ! postpone literal
+	[ hex ] c3 c, [ decimal ] ; \ c3 = RET
+: to  ' ( word ) 6 +  state @ if postpone literal postpone ! else ! then ; immediate
+: +to  ' ( word ) 6 +  state @ if postpone literal postpone +! else +! then ; immediate
+: -to  ' ( word ) 6 +  state @ if postpone literal postpone -! else -! then ; immediate
+
 0 constant false
 -1 constant true
 bye
-- 
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