From 844b06f5f055d4fea8773b418c13c8ea1f61907a Mon Sep 17 00:00:00 2001
From: g012 <leclerc.pascal@gmail.com>
Date: Fri, 6 Oct 2017 15:49:12 +0200
Subject: [PATCH] Added pragma to create opcode aliases.

---
 .travis.yml           |  1 +
 l65.lua               |  8 ++++++++
 samples/vcs_spr48.l65 |  7 ++++---
 vim/syntax/l65.vim    | 12 ++++++++++++
 4 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 99efc26..230b031 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,7 @@ script:
     - ../l65 vcs_flush.l65
     - ../l65 vcs_hello.l65
     - ../l65 vcs_hooks.l65
+    - ../l65 vcs_spr48.l65
     - cd ..
 deploy:
     provider: releases
diff --git a/l65.lua b/l65.lua
index 7b98024..841c268 100644
--- a/l65.lua
+++ b/l65.lua
@@ -77,6 +77,7 @@ end
 opcode_arg_encapsulate(true)
 
 local opcode_encapsulate = {} -- additionnal opcode, to have basic encapsulation (function(a) return a end)
+local opcode_alias = {} -- alternate user names for opcodes
 local opcode_implied = lookupify{
     'asl', 'brk', 'clc', 'cld', 'cli', 'clv', 'dex', 'dey',
     'inx', 'iny', 'lsr', 'nop', 'pha', 'php', 'pla', 'plp',
@@ -507,6 +508,12 @@ local function LexLua(src)
                     table.insert(Keywords_6502, opcode)
                     Keywords[opcode] = syntax6502_on
                     toEmit = {Type = 'Symbol', Data = ';'}
+                elseif dat == 'alias' then
+                    local org,new = get_word(),get_word()
+                    opcode_alias[new] = org
+                    table.insert(Keywords_6502, new)
+                    Keywords[new] = syntax6502_on
+                    toEmit = {Type = 'Symbol', Data = ';'}
                 else generateError("unknown pragma: " .. dat)
                 end
 
@@ -1528,6 +1535,7 @@ local function ParseLua(src, src_name)
             local mod_st, mod_expr, inverse_encapsulate
         for _,op in pairs(Keywords_6502) do
             if tok:ConsumeKeyword(op, tokenList) then
+                if opcode_alias[op] then op = opcode_alias[op] end
                 if opcode_encapsulate[op] then
                     inverse_encapsulate = tok:ConsumeSymbol('!', tokenList)
                     local st, expr = ParseExpr(scope) if not st then return false, expr end
diff --git a/samples/vcs_spr48.l65 b/samples/vcs_spr48.l65
index 081e900..712737b 100644
--- a/samples/vcs_spr48.l65
+++ b/samples/vcs_spr48.l65
@@ -1,6 +1,8 @@
 require'vcs'
 mappers['2K']()
 
+#pragma alias and dna
+
 local i = 0x80
 local ramk=i i=i+51
 local spritestack=i i=i+31
@@ -16,7 +18,6 @@ local img = assert(l65.image("dotbin.png"))
 local sp = sprite{image=img, y0=185, y1=0, yinc=-1}
 for i=1,6 do
     section{"spr"..i, align=256} byte(sp[i])
-    local c = #sp[i]
 end
 
 -- sprite anim frames offset in spr*
@@ -103,7 +104,7 @@ local on_vblank = function()
     inc time bne _noover inc time+1 @_noover
 
     -- frame change
-    lda time; and#3 bne _keep lda seed jsr rand sta seed @_keep
+    lda time dna#3 bne _keep lda seed jsr rand sta seed @_keep
     ldy#8 @_glitch
         lda time+1 cmp glitch_cmphi,y bcc _glitchdone bne _glitchnext
         lda time cmp glitch_cmplo,y bcc _glitchdone
@@ -113,7 +114,7 @@ local on_vblank = function()
     tay jsr setframe
 
     -- position change
-    lda time; and#7 bne _skipmove
+    lda time; and#7 bne _skipmove -- alias opcode 'and' to 'dna' to avoid use of ';', as on line 107
     ldy#6 @_move
         lda time+1 cmp sproff_cmphi,y bcc _stay bne _movenext
         lda time cmp sproff_cmplo,y bcc _stay
diff --git a/vim/syntax/l65.vim b/vim/syntax/l65.vim
index 4e246e6..6852454 100644
--- a/vim/syntax/l65.vim
+++ b/vim/syntax/l65.vim
@@ -577,6 +577,18 @@ syn match l65Opcode /\<sre\%(.[bw]\)\=\>/
 syn match l65Opcode /\<far\>/
 syn match l65Opcode /\<rtx\>/
 syn match l65Opcode /\<xsr\>/
+" Common alias, reomve if desired.
+syn match l65Opcode /\<dna\%(.[bw]\)\=\>/
+syn match l65Keyword /\<dnaimm\>/
+syn match l65Keyword /\<dnazpg\>/
+syn match l65Keyword /\<dnazpx\>/
+syn match l65Keyword /\<dnaabs\>/
+syn match l65Keyword /\<dnaabx\>/
+syn match l65Keyword /\<dnaaby\>/
+syn match l65Keyword /\<dnazab\>/
+syn match l65Keyword /\<dnazax\>/
+syn match l65Keyword /\<dnainx\>/
+syn match l65Keyword /\<dnainy\>/
 
 " Define the default highlighting.
 " For version 5.7 and earlier: only when not done already