ID:2652318
 
Resolved
Generators could not be assigned to particle datums at compile-time.
BYOND Version:514.1543
Operating System:Windows 10 Pro 64-bit
Web Browser:Chrome 88.0.4324.96
Applies to:Dream Maker
Status: Resolved (514.1544)

This issue has been resolved.
Descriptive Problem Summary:
Even correcting for http://www.byond.com/forum/post/2652272, non-constants are not allowed for the particle variables that explicitly should support it.

It even says in stddef.dm "particle spawn settings; use generator() for these"

Code Snippet (if applicable) to Reproduce Problem:
Your snow particle example (/{notes}/particles).
particle/snow
width = 500 // 500 x 500 image to cover a moderately sized map
height = 500
count = 2500 // 2500 particles
spawning = 3 // 3 new particles per client tick
bound1 = list(-1000, -300, -1000) // end particles at Y=-300
lifespan = 600 // last 600 client ticks max
fade = 50 // fade out over the last 50 ticks if still on screen
// spawn within a certain x,y,z space
position = generator("box", list(-300,250,0), list(300,300,100))
// control how the snow falls
gravity = list(0, -3.2)
friction = 0.2 // shed 20% of velocity and drift every client tick
drift = generator("sphere", 0, 2)
obj/snow
screen_loc = "CENTER"
particles = new/particle/snow

mob
proc/CreateSnow()
client?.screen += new/obj/snow


Expected Results:
The code in the ref to work.

Actual Results:
main.dm:44:error: : expected a constant expression


Workarounds: non-usage of the feature

Gah, my bad. I think I messed up and failed to make generators compile to init procs.
Lummox JR changed status to 'Verified'
Lummox JR resolved issue with message:
Generators could not be assigned to particle datums at compile-time.