Sequence diagram arrows only go left to right

Arrows must be left to right, trying to do right to left causes errors:

sequenceDiagram
  A -> B: Thing
  A <- B: Return

Parse error on line 3:
... A -> B: Thing  A <- B: Return
----------------------^
Expecting 'NL', 'AS', ',', 'SOLID_OPEN_ARROW', 'DOTTED_OPEN_ARROW', 'SOLID_ARROW', 'DOTTED_ARROW', 'SOLID_CROSS', 'DOTTED_CROSS', 'TXT', got '-'

This is something I was using in my PlantUML diagrams but it seems like Mermaid doesn’t like it. Is this something you’d like to see added?

[whitelizard]

Hi!

I was actually trying in a flow chart to have an arrow in the opposite direction, and finally found this issue.

My view and suggestion is that “logically” it could be a forward arrow, in how the layout and internal logic is handled, but the feature could perhaps simply be to enable ability to render an arrow in the opposite direction?

[knsv]

That makes sense for compatability. Ideally mermaid should handle the PlantUML syntax. I will add this to the “backlog” but I cant promise any release date. This is a good starter task.