explicitly document the use of ttype for async ops

[andre-merzky]

No description provided.

[vivek-bala]

Not sure which async ops this refers to. @andre-merzky any pointers?

[andre-merzky]

All methods in SAGA can be called as async methods:

f = rs.filesystem.File('/etc/passwd')

# synchronous call
print f.get_size()

# this is equivalent to this version which creates a task in a final state (synchronous call)
task = f.get_size(ttype=rs.SYNC)
print task.get_result()

# this is a version creating a RUNNING task which one needs to wait on to get the result:
task = f.get_size(ttype=rs.ASYNC)
task.wait()
print task.get_result()

# this is a version creating a NEW task which one needs to run and wait on to get the result:
task = f.get_size(ttype=rs.TASK)
task.run()
task.wait()
print task.get_result()

This holds for every method of the functional API packages. Its rarely used, but still, it needs proper documentation.

[vivek-bala]

Thanks for the info! I'll leave this ticket open then.