First proposition for better error messages
With this patch the user gets a hint about what is wrong in his input file as requested in #32 (closed)
If one omits the TRACK command OPAL writes
Error> RUN,METHOD="PARALLEL-T",BEAM=BEAM1,FIELDSOLVER=FS1,DISTRIBUTION=DIST1;
Error> Syntax error, the command 'RUN' could belong to
Error> - the command TRACK
Error> but it's not present!
If parts of a definition are commented out then OPAL writes
Error> MAXSTEPS=600000,DT=2e-13,ZSTOP=0.3;
Error> ^
Error> Syntax error, either the keyword REAL is missing or
Error> the attribute 'MAXSTEPS' could belong to
Error> - the command TRACK
Error> but it's not present!
Disadvantage: one has always to use REAL when defining variables. e.g.
MINSTEPFORREBIN = 500;
isn't accepted any more. Instead one has to write
REAL MINSTEPFORREBIN = 500;