CNI for Lua

CNI for Lua

A pure Lua parser for the CNI configuration format using patok and piecemeal.


First, import the parser and initialize it: local cni = require 'cni':new(). You can initialize it later, or initialize multiple parsers.

Then, you can parse some CNI text: local f = cni:parse 'a = b'. The return value is the end string index of the parse - you can compare it to the lenght of your input to determine if the parse was complete. If the parse is impossible (i.e incorrect rather than incomplete), cni:parse will panic, so call it inside of pcall if that's unacceptable.

CNI is a streaming parser, so you can call parse again. By default, state is kept, so section headers remain effect. For instance, cni:parse '[a]'; cni:parse 'b = c' is equivalent to cni:parse '[a]\nb=c'. If you want to reset the internal state, you can call cni:reset().

Once you're done parsing (or in-between parses), you can access the internal state. There are two ways to access it: key-value mode and pseudo-structured mode. Key-value mode has full keys. For instance, as per above, cni.kv['a.b'] == 'c'.

Pseudo-structured mode is not native, and needs to be compiled first: local out = cni:compile(). Note that the compilation is cached, so calling cni:compile() multiple times does not carry an additional performance penalty, unless you parse more data. Afterwards, you can access the configuration data as if it was a standard lua object: out.a.b() == 'c'. Note that a call with () is required to extract the value, because it is valid for a node to be both a node and a leaf. Such as with a = b and a.b = c.

For an example of use in-code, see the example.lua file.