38 lines
1.1 KiB
Markdown
38 lines
1.1 KiB
Markdown
# ImmuTable
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This is a native Lua library that allows the creation of immutable tables.
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## Build
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Lua 5.1/5.2/5.3+ or LuaJIT 2.0+ built from source code is a prerequisite. Lua can be downloaded from the [lua.org downloads page](https://www.lua.org/ftp/), and LuaJIT can be downloaded from the [LuaJIT.org downloads page](http://luajit.org/download.html).
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`make LUA=/path/to/lua_dir`
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or for LuaJIT: `make LUA=/path/to/luajit_dir LUASUFFIX=jit`
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## Usage
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```
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local immutable = require "immutable"
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local Vec2 = immutable({"x","y"}, {
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len2=function(self)
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return self.x*self.x + self.y*self.y
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end,
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is_a_vec2 = true,
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__add=function(self, other)
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local cls = getmetatable(self)
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return cls(self.x+other.x, self.y+other.y)
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end,
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__tostring=function(self)
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return "Vec2("..tostring(self.x)..", "..tostring(self.y)..")"
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end,
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})
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local v = Vec2(2, 3)
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assert(v.x == 2 and v.y == 3)
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local v2 = v + Vec2(0, 1)
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assert(v2 == Vec2(2, 4))
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local t = {[v2]='yep'}
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assert(t[Vec2(2,4)] == 'yep')
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assert(Vec2(2,0):len2() == 4)
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assert(Vec2(2,0).is_a_vec2)
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```
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