LazyLuaLinq provides a simple, lazy implementation of linq-like functions for Lua. With LazyLuaLinq, you can implement data transformation in elegant, expressive queries akin to SQL:
local topProductsAlphabetically = from(getProducts())
:where(function(product) return product.rating > 4.0 end)
:orderBy(function(product) return product.name end)
:toArray()Queries are executed lazily, i.e. queries will only iterate their source as far as required. Consider the following (contrived) example:
local number = from { 3, 2, 1, 0 }
:select(function(n) return 1 / n end)
:first(function(n) return n == 1 end)Without lazy evaluation, this code would result in a division by zero when calculating the last element of the sequence. Luckily, with LazyLuaLinq, this won't happen, as the second-to-last element fulfils the condition specified in the call to first and therefore prevents further iteration.
Check out the documentation on Github Pages or get lazylualinq now on LuaRocks!
In order to use lazylualinq locally, we recommend installing it from LuaRocks:
# Note: Depending on your setup, you may have to run this using sudo.
luarocks install --server=https://luarocks.org/dev lazylualinqThen, just require it from your code and start using it!
local linq = require("lazylualinq")
local seq = linq { 1, 2, 3 }
:where(function(v) return v % 2 == 1 end)
-- seq is now equivalent to linq { 1, 3 }
If you want to make changes to lazylualinq, you should install the test dependencies first:
sudo luarocks test --prepareThen, you can run the tests using luarocks test. If you're not familiar with our unit testing framework busted, now would be a great time to read up on it!
Got something that you feel is worth sharing? We'd love for you to open up a PR!
Do you want to help out, but have no idea what to work on? Check out our issues on Github.
- Documentation: https://henkoglobin.github.io/lazylualinq/
- LuaRocks: https://luarocks.org/modules/henkoglobin/lazylualinq
- Issues: https://github.com/Henkoglobin/lazylualinq/issues
- Edulinq blog series by Jon Skeet: https://codeblog.jonskeet.uk/category/edulinq/
This is free and unencumbered software released into the public domain.
Check out the full license here: https://github.com/Henkoglobin/lazylualinq/blob/main/LICENSE