State labels in explicit-drn are parsed incorrectly

[jjguijt]

When using storm-pomdp to transform a POMDP to a pMC without (user created) labels, states in the resulting explicit-drn file will be labeled with the expression from the property (e.g. when using [F a = b] as a prop, a state in the resulting file may be labeled with (a = b).

When the resulting file is parsed by storm-pars, the parentheses are not taken into account. Alternatively, this could be considered a bug in storm-pomdp (since it introduces the spaces) or it can be considered bad practice not to use labels.

For example (is used a = s1 in the prop):

$ storm-pars --explicit-drn shields-warehouse/storm-pmc-g-no-crash.drn
Storm-pars 1.3.1 (dev)

Date: Thu Jul 18 17:33:53 2019
Command line arguments: --explicit-drn shields-warehouse/storm-pmc-g-no-crash.drn
Current working directory: /home/jeremy/study/internship

Time for model construction: 1.946s.

-------------------------------------------------------------- 
Model type:     DTMC (sparse)
States:     441
Transitions:    2457
Reward Models:  none
State Labels:   4 labels
   * s1) -> 420 item(s)
   * init -> 1 item(s)
   * (a -> 420 item(s)
   * != -> 420 item(s)
Choice Labels:  none
--------------------------------------------------------------

I can add more info/source files if it's needed.

[sjunges]

In short, we do recommend to use labels here, however, we have fixed the issue by putting quotation marks around labels with spaces. The parser should also adhere to this.

[jjguijt]

Thanks!