# venus lua parser
A parser that loads venus files into lua. Written in lua.  
The parser reads a venus file and replaces venus syntax by lua syntax.  
It can also load and run the result.

## features
### foreach
The `foreach` statement will geneate a `pairs` statement.

```lua
local table = {2,1,3,"test"}

foreach el in table {
  print(el)
}
```
will generate
```lua
local table = {2,1,3,"test"}

for _, el in table do
  print(el)
end
```

### comments
for comments `--`, `//` and `##` can be used
if something follows a `--` it will always be treated as comment

### curly braces
The `do`,`then` and `end` statements can be replaced by curly brace syntax.  
They can be used in functions, loops, conditions.  
For example:
```lua
do {
	local table = {2,1,3,"test","test2",3}

	function findTest(t) {
		repeat {
			local found = false
			local el = table.remove(t)
			if el == "test" {
				found = true
			} else {
				print(el)
			}
		} until found
	}
}
```
will generate
```lua
do
	local table = {2,1,3,"test","test2",3}

	function findTest(t) 
		repeat
			local found = false
			local el = table.remove(t)
			if el == "test" then
				found = true
			else
				print(el)
			end
		until found
	end
end
```

### functions
`fn` can be used instead of `function`.
```lua
fn test() {
	print("hi")
}
```
will generate
```lua
function test()
	print("hi")
end
```

### lambdas
Lambda syntax `(args) => {...}` can be used to create functions.
```lua
local result
fn store_it(f) {
	result = f(10,6)
}

store_it((a,b) => {
	return (a - b) * 2
})
```
will generate
```lua
local result
function store_it(f)
	result = f(10,6)
end

store_it(function(a,b)
	return (a - b) * 2
end)
```

### incrrement and decrement
`++` and `--` can be used to in/decrement by 1
```lua
local i = 0
local j = 0

i++
j--
```
will generate
```lua
local i = 0
local j = 0

i = i + 1
j = j - 1
```
`--` can also be a comment!  
If there is anything behind a `--` the `--` treated as comment.

### assignments
Assignment operators `+=`, `-=`, `*=`, `/=`, `^=` and `.=` can be used.
```lua
local a = 0
-- increment
a += 2
-- decrement
a -= 1
-- multiply
a *= 8
-- divide
a /= 2
-- to the power of
a ^= 3
-- concatenate string
a .= " str"
```
will generate
```lua
local a = 0
-- increment
a = a + 2
-- decrement
a = a - 1
-- multiply
a = a * 8
-- divide
a = a / 2
-- to the power of
a = a ^ 3
-- concatenate string
a = a .. " str"
```

## working with the parser
### loading
The init.lua returns a function for loading the parser.  
You have to call it with the path to the script itself as argument.  
In case you have the VenusParser directory within your project's  
ways of loding it may be:
```lua
--in case your project is run within it's own folder
local vc = dofile("VenusParser/init.lua")("VenusParser/")
--in case you have a variable called project_loc containing the path to your projects folder
local vc = dofile(project_loc.."/VenusParser/init.lua")(project_loc.."/VenusParser/")
--using require
local vc = require("VenusParser")("VenusParser/")
```
When it is loaded it can also be accessed with the global called "VenusParser".

### running venus files
`vc.dovenus(file)` works like `dofile(file)`  
It's argument can be a relative or absolute path to the file that should be run.

### loading venus files
`vc.loadvenus(file)` works like `loadfile(file)`  
It's argument can be a relative or absolute path to the file that should be loaded.  
It returns a function that runs the generated lua.

### generating lua code
`vp.tl_venus_file(file)` returns the lua generated from the files contents  
It's argument can be a relative or absolute path to the file that should be translated.  
It returns the generated lua as string.

`vp.tl_venus_string(str)` returns the lua generated from the given string  
It returns the generated lua as string.

### generating lua files
`vp.convert_venus_file(venus_file_in,lua_file_out)` generates a lua file  
It's arguments can be relative or absolute paths.  
The venus_file_in will be converted to lua and written to lua_file_out.
