ASM

A small DSL engine for Luau: evaluate string-based expressions like ADD(VAR("A"), VAR("B")) against a table of variables.

Installation (Wally)

Add to your wally.toml:

[dependencies]
ASM = "gt/asm@0.1.0"

Then:

wally install

Usage

local ASM = require(Packages.ASM)

local result = ASM:Eval([[ADD(VAR("A"), VAR("B"))]], { A = 10, B = 15 })
print(result) --> 25

-- Compile once, run many times with different variables
local compiled = ASM:Build([[POW(VAR("base"), VAR("exp"))]])
print(compiled({ base = 2, exp = 10 })) --> 1024

-- Non-throwing variant
local ok, resultOrErr = ASM:TryEval([[ADD(VAR("A"), VAR("B"))]], { A = 1 })
if not ok then
	warn(tostring(resultOrErr))
end

Registering custom functions

ASM:Register("DOUBLE", function(x: number)
	return x * 2
end)

ASM:Eval("DOUBLE(21)") --> 42

Conditional logic

true / false are recognized as boolean literals. IF, AND, OR, and NOT are built into the parser (not regular registered functions), so they evaluate lazily — IF(cond, a, b) only evaluates the taken branch, and AND/OR short-circuit:

ASM:Eval([[IF(GT(VAR("hp"), 0), "alive", "dead")]], { hp = 0 })
--> "dead"

-- The else-branch never runs DIV(1, 0) since the condition is true:
ASM:Eval([[IF(true, 42, DIV(1, 0))]])
--> 42

ASM:Eval([[AND(GT(VAR("hp"), 0), NOT(VAR("isStunned")))]], { hp = 10, isStunned = false })
--> true

Comparison built-ins: EQ, NEQ, LT, GT, LTE, GTE.

Local development

Requires Aftman to pin tool versions.

aftman install        # installs rojo, wally, selene, stylua at pinned versions
wally install         # installs TestEZ as a dev-dependency

Serve the package alone (no game, just for sourcemap/inspection)

rojo serve default.project.json

Run tests

Open test.project.json in Rojo, connect Studio, then press Play — test/init.server.luau boots TestEZ against every *.spec.luau file under src/.

Headless (CI), see .github/workflows/ci.yml.

Lint / format

selene src
stylua --check src

Publishing a new version

1. Bump version in wally.toml.
2. Add an entry to CHANGELOG.md.
3. wally publish.