CPP pushed a fix for pcall, so please try again with a new dev build.
memory.usememorydomain("System Bus")
event.on_bus_read(function(addr, val, flags)
print("TEST")
end, 0xFFEA)
while true do
emu.frameadvance()
endAnd then a "script.lua" stub that executes the main Fennel file:Language: fennel(console.log "Hello Fennel") (console.log (string.format "ROM name: %q" (gameinfo.getromname))) (local fennel (require :fennel)) ;; for fennel.view (console.log "joypad" (fennel.view (joypad.get) {:one-line? true}))
The "fennel" module comes from fennel.lua, which you just have to install in the directory alongside your scripts. The two-file approach works fine. But I found a way to get the same effect with just one file. The file is simultaneously a Lua program and a Fennel program; i.e., a polyglot. It looks like this:Language: luarequire("fennel").install().dofile("script.fnl")
The ;; marks a comment in Fennel. So from the point of view of a Fennel interpreter, the first and last lines of the file disappear, leaving only the lisp code in between. In Lua, ; is an empty statement, a no-op separator. So the Lua interpreter sees and executes the require("fennel").install().eval(...). The [==[ marks the beginning of a long literal string that lasts until the ]==] on the last line—encompassing the entire text of the Fennel program. To the Lua interpreter, the Fennel part of the program looks like one long string, which gets passed to the fennel.eval function. It would be nice if only required adding something to the top of the file, not both top and bottom, but I couldn't think of a way to do that. I've found just one problem with the polyglot approach, which is that BizHawk won't let you load a file with a ".fnl" filename extension with the --lua option on the command line. I want to name the program file "script.fnl", so that when I edit it, I get syntax highlighting and automatic indentation appropriate for Fennel. But BizHawk's --lua option only allows ".lua" and ".txt" as filename extensions, and silently ignores files with any other extension. (Except for ".luases", which I don't know what that is.) You can load .fnl files from the "Open Script" UI in the Lua Console; it's just the --lua option that doesn't work. So I have to name the file "script.lua", which adds inconvenience when editing it as Fennel code. So I might stick with the two-file method anyway. If you want to see how the Fennel code compiles to Lua, you can paste it in here.Language: lua;; return require("fennel").install().eval([==[ (console.log "Hello Fennel") (console.log (string.format "ROM name: %q" (gameinfo.getromname))) (local fennel (require :fennel)) ;; for fennel.view (console.log "joypad" (fennel.view (joypad.get) {:one-line? true})) ;; ]==])
Hey look buddy, I'm an engineer. That means I solve problems. Not problems like "What is software," because that would fall within the purview of your conundrums of philosophy. I solve practical problems. For instance, how am I gonna stop some high-wattage thread-ripping monster of a CPU dead in its tracks? The answer: use code. And if that don't work? Use more code.
Language: Lualocal val = { ball = { -- ... collided_with_flipper = false }, collectible = { --... }, cannon = { -- ... }, misc = { --... }, left_flipper = { --... }, right_flipper = { --... } } event.on_bus_exec(function(addr, val, flags) val.ball.collided_with_flipper = true end, 0x08015C1E)
error running function attached by the event OnMemoryExecute
Error message: [string "main"]:221: attempt to index a number value (local 'val')Why didn't the first code work?Language: Lualocal collided_with_flipper = false event.on_bus_exec(function(addr, val, flags) collided_with_flipper = true end, 0x08015C1E)
Why didn't the first code work?
local val = {function(addr, val, flags)Hey look buddy, I'm an engineer. That means I solve problems. Not problems like "What is software," because that would fall within the purview of your conundrums of philosophy. I solve practical problems. For instance, how am I gonna stop some high-wattage thread-ripping monster of a CPU dead in its tracks? The answer: use code. And if that don't work? Use more code.
If you're like me, you were excited when you saw that BizHawk has a built-in built-in SQL module, because easy access to SQLite is very handy. But then you were disappointed when you tried to use it, because the interface is awkward and confusing. Here are some things that make it hard to use:Language: lualocal sqlite = require("sqlite") local db = sqlite.open("lag.db") local lag_frames = {} for _, row in ipairs(assert(db:execute("SELECT frame, islagged FROM lag"))) do if row.islagged ~= 0 then lag_frames[row.frame] = true end end
Download B.luaLanguage: luaSQL.opendatabase("A.db") function assert_writecommand_ok(res) assert(res == "Command ran successfully", res) end assert_writecommand_ok(SQL.writecommand( [[CREATE TABLE IF NOT EXISTS lag ( frame INTEGER NOT NULL, islagged INTEGER NOT NULL ) STRICT]])) event.onframeend(function () assert_writecommand_ok(SQL.writecommand(string.format( "INSERT INTO lag VALUES (%d, %d)", emu.framecount(), ({[false] = 0, [true] = 1})[emu.islagged()] ))) end)
If you load these two scripts at the same time, one of them will crash with an error, depending on which was loaded first:Language: luaSQL.opendatabase("B.db") function assert_writecommand_ok(res) assert(res == "Command ran successfully", res) end assert_writecommand_ok(SQL.writecommand( [[CREATE TABLE IF NOT EXISTS inputpoll ( cycles INTEGER NOT NULL ) STRICT]])) event.oninputpoll(function () assert_writecommand_ok(SQL.writecommand(string.format( "INSERT INTO inputpoll VALUES (%d)", emu.totalexecutedcycles() ))) end)
error running function attached by the event OnInputPoll
Error message: [string "main"]:2: SQLite Error 1: 'no such table: inputpoll'.
NLua.Exceptions.LuaScriptException: [string "main"]:2: SQLite Error 1: 'no such table: lag'.
CREATE TABLE tbl (x INTEGER, y STRING);
INSERT INTO tbl VALUES(123,'abc');
INSERT INTO tbl VALUES(999,'hello');
INSERT INTO tbl VALUES(456,NULL);
INSERT INTO tbl VALUES(NULL,'xyz');
| x | y |
|---|---|
| 123 | 'abc' |
| 999 | 'hello' |
| 456 | NULL |
| NULL | 'xyz' |
{{x = 123, y = "abc"},
{x = 999, y = "hello"},
{x = 456},
{y = "xyz"}}
{["x 0"] = 123, ["y 0"] = "abc",
["x 1"] = 999, ["y 1"] = "hello",
["x 2"] = 456, ["y 2"] = userdata,
["x 3"] = userdata, ["y 3"] = "xyz"}
Download B2.luaLanguage: lualocal sqlite = require("sqlite") local db = sqlite.open("A2.db") assert(db:execute( [[CREATE TABLE IF NOT EXISTS lag ( frame INTEGER NOT NULL, islagged INTEGER NOT NULL ) STRICT]])) event.onframeend(function () assert(db:execute(string.format( "INSERT INTO lag VALUES (%s, %s)", sqlite.escape(emu.framecount(), emu.islagged()) ))) end)
As an extra precaution, the module also restores the global database connection to what is was originally, after executing each statement. That means that scripts that use the wrapper module can run at the same time as up to one other script that uses the SQL module directly. (If two or more other scripts use the SQL module directly, they will still stomp on each other, and there's nothing we can do about that.)Language: lualocal sqlite = require("sqlite") local db = sqlite.open("B2.db") assert(db:execute( [[CREATE TABLE IF NOT EXISTS inputpoll ( cycles INTEGER NOT NULL ) STRICT]])) event.oninputpoll(function () assert(db:execute(string.format( "INSERT INTO inputpoll VALUES (%s)", sqlite.escape(emu.totalexecutedcycles()) ))) end)