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| − | == Loops ==
| + | #REDIRECT [[Welcome to NETIO resources & projects & documentation overview]] |
| − | === Numeric for ===
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| − | local arr = {2,3,7,5}
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| − | for i=1,#arr do logf("%d",arr[i]) end
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| − | <code><b>for</b> initVar,limit,increment <b>do</b></code>
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| − | * <i>number assignment</i> <code>initVar</code> inits loop-local variable
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| − | * <i>number</i> <code>limit</code> loops until initVar reaches this value
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| − | * <i>optional number</i> <code>increment</code> after each loop initVar increment by this value (default 1)
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| − | | |
| − | === Generic for ===
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| − | Most common example (the order of elements in <code>pairs()</code> is not guaranteed)
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| − | local tab = {one=1, two=2, three=3}
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| − | for key,val in pairs(tab) do logf("%s:%d",key,val) end
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| − | Generic for syntax
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| − | for var_1, ..., var_n in explist do block end
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| − | is equivalent to (Full explanation [https://www.lua.org/pil/7.2.html here].)
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| − | do
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| − | local _f, _s, _var = explist
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| − | while true do
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| − | local var_1, ... , var_n = _f(_s, _var)
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| − | _var = var_1
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| − | if _var == nil then break end
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| − | block
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| − | end
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| − | end
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| − | | |
| − | Iterator closure that holds its state
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| − | function iter(a)
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| − | local i = 0
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| − | return function()
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| − | i = i+1
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| − | return a[i]
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| − | end
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| − | end
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| − |
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| − | local arr = {2,3,7,5}
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| − | for value in iter(arr) do
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| − | logf("%d",value)
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| − | end
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| − | | |
| − | Stateless iterator (in this case returns variable list: key and value)
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| − | function iter(a,i)
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| − | i = i+1
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| − | if a[i] then return i,a[i] end
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| − | end
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| − |
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| − | local arr = {2,3,7,5}
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| − | for k,v in iter,arr,0 do
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| − | logf("%d:%d",k,v)
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| − | end
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| − | | |
| − | Same effect using <code>ipairs()</code> Lua function (without initial state)
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| − | for k,v in ipairs(arr) do
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| − | logf("%d:%d",k,v)
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| − | end
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| − | | |
| − | Now return to the most common example above using <code>pairs()</code> Lua function and read about <code>pairs()</code> and <code>ipairs()</code> implementation [https://www.lua.org/pil/7.3.html here].
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