From: Jonas Hvid <mail@johv.dk>
Date: Tue, 10 Dec 2019 15:26:36 +0000 (+0100)
Subject: Define IF and THEN
X-Git-Url: https://git.rrq.au/?a=commitdiff_plain;h=03fd7979b12ff7cc5d074bb83c9d4e3fcdf616c3;p=rrq%2Fjonasforth.git

Define IF and THEN
---

diff --git a/main.asm b/main.asm
index e6b0ac2..086d1dc 100644
--- a/main.asm
+++ b/main.asm
@@ -288,18 +288,19 @@ forth INTERPRET, 'INTERPRET'
   ;; Stack is (word length word length).
   dq FIND                       ; Try to find word
   dq DUP_
-  dq ZBRANCH, 8 * 20            ; Check if word is found
+  dq ZBRANCH, 8 * 22            ; Check if word is found
 
   ;; - Word is found -
 
-  dq STATE, GET, ZBRANCH, 8 * 9 ; Check whether we are in compilation or immediate mode
+  dq STATE, GET, ZBRANCH, 8 * 11 ; Check whether we are in compilation or immediate mode
 
   ;; (Word found, compilation mode)
-  dq DUP_, IS_IMMEDIATE, NOT_, ZBRANCH, 8 * 4 ; If the word is immediate, continue as we would in immediate mode
+  dq DUP_, IS_IMMEDIATE, NOT_, ZBRANCH, 8 * 6 ; If the word is immediate, continue as we would in immediate mode
 
   ;; Otherwise, we want to compile this word
   dq TCFA
   dq COMMA
+  dq DROP, DROP
   dq EXIT
 
   ;; (Word found, immediate mode)
@@ -557,6 +558,11 @@ forth OUTOF_IMMEDIATE, ']'
   dq LIT, 1, STATE, PUT_BYTE
   dq EXIT
 
+forth_asm TICK, "'"
+  lodsq
+  push rax
+  next
+
 forth MAIN, 'MAIN'
   dq HELLO
   dq INTERPRET
@@ -591,7 +597,7 @@ DOTU.printed_length dq ?
 
 ;; Reserve space for compiled words, accessed through HERE.
 here dq here_top
-here_top rq $2000
+here_top rq $4000
 
 ;; Return stack
 rq $2000
diff --git a/sys.f b/sys.f
index 23fed87..df2d231 100644
--- a/sys.f
+++ b/sys.f
@@ -13,3 +13,16 @@ EXIT [
 : / /MOD DROP ;
 : MOD /MOD SWAP DROP ;
 : NEG 0 SWAP - ;
+
+: IF IMMEDIATE
+  ' 0BRANCH ,
+  HERE @
+  0 ,
+;
+
+: THEN IMMEDIATE
+  DUP
+  HERE @ SWAP -
+  SWAP !
+;
+