How invoke a function given its name in string in Lua/Torch?

Question

I want to evaluate a string name as a function in Lua/Torch. Below is an example of what I want to do:

require 'torch'

tensorType = torch.getdefaulttensortype()
print (tensorType) -- Will print "torch.DoubleTensor"

My goal is to be able to use the string in tensorType as name of a function and evaluate that function like follow:

tensorType(some arguments)

In MATLAB and Python there is a `eval()' function which can execute arbitrary strings. Is there such a function in Lua/Torch?

How can I do that in Torch/Lua?

Answer 1

You can use loadstring but that's generally not recommended because it has to compile code at runtime. What is this for?

Answer 2

First extract the name of the field from the string:

k=tensorType:match("%.(.+)$")

Then use the name to call the function:

torch[k](some arguments)

Answer 3

You could also try lutorpy , you will have a lua engine in python, thus, you can load any lua/torch library, and you can run lua code with "lua.eval('torch.DoubleTensor(3,4)')". Check lutorpy for more details.