Piecewise signal support

[mvesco]

Hi wavedrompy team, I am trying to compile code with the recently added "pw" (piecewise) keyword used for signals but I get this error:

TypeError: unhashable type: 'dict'

The code piece is the following:

import wavedrom
svg = wavedrom.render("""
{"signal": [
  {"name": "clock",    "wave": "p......."},
  {"name": "sawtooth", "wave": ["pw", {"d": ["m",1,0, "l",2,1, "v",-1, "l",2,1, "v",-1]}]},
  {"name": "triangle", "wave": ["pw", {"d": "m,0,0  l,2,1  l,2,-1  l,2,1  l,2,-1"}]},
  {"name": "RC", "wave": ["pw", {"d": "m,0,0 q,.5,1,1,1 h,1 q,.5,-1,1,-1 h,1 q,.5,1,1,1 h,1"}]},
  {"name": "sin", "wave": ["pw", {"d": "m,0,.5 q,.25,1,.5,0 t,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0,.5,0"}]}
]}
""")
svg.saveas("demo_pw.svg")

Are you planning to release a new update soon with this feature and probably other recent features like "label" for registers? Thanks in advance!