Change input format to YAML

[heikef]

I got some user feedback regarding the input of gimic and would like to open an issue to discuss on how things should be restructured or not.

[bast]

My long term plan is to switch input format to YAML format. I have a related project where we want to develop the next generation input parser and replace libgetkw. All suggestions welcome for features you would like to have implemented there.

[bast]

And I think input and scripts is a too wide topic. I think scrips and input format are two different topics.

[heikef]

Why YAML? I found this page: http://yaml.org/ Does not look tempting to me.

Changed the discussion topic for not being too wide. I think this is related to input format plans.

[bast]

That page is scary but YAML is the de-factor standard input format. Easy to parse for machines, easy to write for machines, easy to write for humans, readable for humans. You can have nested sections. My favorite format. But don't worry, before going there I would create a proper proposal demonstrating how the new input would look compared to now. What I can already promise is that it will look a lot cleaner and easier to read.

[bast]

Most importantly: it is a standard format. Creating own formats is not a good idea.

[bast]

Example - instead of:

calc=integral          # cdens, integral, edens, divj
#dryrun=off        # don't actually calculate (good for tuning grids, etc.)
title=""
basis="MOL"
xdens="XDENS"
debug=1           # debug print level
openshell=false
# show_axis=true   # mark "up" axis in .xyz files
magnet_axis=X #[-] i,j,k || x,y,z -> align magnet along axis

# grid type can be: base/std, bond or file (see examples below)
Grid(bond) {                    # define grid orthogonal to a bond
    type=gauss                  # gauss distribution of grid points
    bond=[1,2]
    fixpoint=4
    distance=1.32               # place grid 'distance' between atoms
    gauss_order=9               # order for gauss quadrature
    grid_points=[30, 30, 0]
    height=[-5.0, 5.0]
    width=[-2.2, 5.0]
}

With YAML:

calc: integral          
title: ""
basis: "MOL"
xdens: "XDENS"
debug: 1           
openshell: false
magnet_axis: X 

grid:
  type: gauss                  
  bond: [1, 2]
  fixpoint: 4
  distance: 1.32 
  gauss_order: 9 
  grid_points: [30, 30, 0]
  height: [-5.0, 5.0]
  width: [-2.2, 5.0]

[heikef]

I see your point. However, I am happy that this is not on the desk right now. ;)

[bast]

I will work on the input parser independently of GIMIC. Later GIMIC can decide whether it likes it or not.

[heikef]

Ok - the example you showed is less scary that the web page. I suggest to take this up into an issue/meeting discussion. Would that be ok?

[bast]

That's fine. There is no rush with this.

[heikef]

There is always a rush. I just put in on the agenda for our next project meeting.

[heikef]

So we go for YAML. Replace getkw python.