Revert "Singletons + refactor of /datum/observ (#15487)" (#15515)

code/modules/projectiles/guns/projectile/automatic.dm

@@ -126,7 +126,7 @@
 	slot_flags = SLOT_BACK
 	load_method = MAGAZINE
 	fire_sound = 'sound/weapons/gunshot/gunshot_rifle.ogg'
-	empty_sound = /singleton/sound_category/out_of_ammo_rifle
+	empty_sound = /decl/sound_category/out_of_ammo_rifle
 	magazine_type = /obj/item/ammo_magazine/c762
 	allowed_magazines = list(/obj/item/ammo_magazine/c762)
 

code/modules/projectiles/guns/projectile/dartgun.dm

@@ -102,7 +102,7 @@
 		to_chat(user, "<span class='notice'>[src] contains:</span>")
 		for(var/obj/item/reagent_containers/glass/beaker/B in beakers)
 			for(var/_R in B.reagents.reagent_volumes)
-				var/singleton/reagent/R = GET_SINGLETON(_R)
+				var/decl/reagent/R = decls_repository.get_decl(_R)
 				to_chat(user, "<span class='notice'>[B.reagents.reagent_volumes[_R]] units of [R.name]</span>")
 
 /obj/item/gun/projectile/dartgun/attackby(obj/item/I as obj, mob/user as mob)
@@ -138,7 +138,7 @@
 			dat += "Beaker [i] contains: "
 			if(LAZYLEN(B.reagents.reagent_volumes))
 				for(var/_R in B.reagents.reagent_volumes)
-					var/singleton/reagent/R = GET_SINGLETON(_R)
+					var/decl/reagent/R = decls_repository.get_decl(_R)
 					dat += "<br>    [B.reagents.reagent_volumes[_R]] units of [R.name], "
 				if (check_beaker_mixing(B))
 					dat += text("<A href='?src=\ref[src];stop_mix=[i]'><font color='green'>Mixing</font></A> ")

code/modules/projectiles/guns/projectile/musket.dm

@@ -51,11 +51,11 @@
 			to_chat(user, SPAN_WARNING("\The [src] is already full of gunpowder."))
 			return
 		var/obj/item/reagent_containers/C = W
-		if(C.reagents.has_reagent(/singleton/reagent/gunpowder, 5))
+		if(C.reagents.has_reagent(/decl/reagent/gunpowder, 5))
 			if(do_after(user, 15))
 				if(has_powder)
 					return
-				C.reagents.remove_reagent(/singleton/reagent/gunpowder, 5)
+				C.reagents.remove_reagent(/decl/reagent/gunpowder, 5)
 				has_powder = TRUE
 				to_chat(user, SPAN_NOTICE("You fill \the [src] with gunpowder."))
 
@@ -69,4 +69,4 @@
 	amount_per_transfer_from_this = 5
 	possible_transfer_amounts = list(5)
 	volume = 30
-	reagents_to_add = list(/singleton/reagent/gunpowder = 30)
+	reagents_to_add = list(/decl/reagent/gunpowder = 30)

code/modules/projectiles/guns/projectile/revolver.dm

@@ -13,7 +13,7 @@
 	ammo_type = /obj/item/ammo_casing/a357
 	magazine_type = /obj/item/ammo_magazine/a357
 	fire_sound = 'sound/weapons/gunshot/gunshot_revolver.ogg'
-	empty_sound = /singleton/sound_category/out_of_ammo_revolver
+	empty_sound = /decl/sound_category/out_of_ammo_revolver
 	var/chamber_offset = 0 //how many empty chambers in the cylinder until you hit a round
 
 /obj/item/gun/projectile/revolver/verb/spin_cylinder()

code/modules/projectiles/guns/projectile/rifle.dm

@@ -294,7 +294,7 @@
 	item_state = "gauss_thumper"
 	caliber = "gauss"
 	origin_tech = list(TECH_COMBAT = 3, TECH_MATERIAL = 2)
-	fire_sound = /singleton/sound_category/gauss_fire_sound
+	fire_sound = /decl/sound_category/gauss_fire_sound
 	load_method = MAGAZINE
 	handle_casings = DELETE_CASINGS
 
@@ -321,7 +321,7 @@
 	desc = "An outdated and power hungry gauss cannon, modified to deliver high explosive rounds at high velocities."
 	icon = 'icons/obj/guns/gauss_thumper.dmi'
 	icon_state = "gauss_thumper"
-	fire_sound = /singleton/sound_category/gauss_fire_sound
+	fire_sound = /decl/sound_category/gauss_fire_sound
 	fire_delay = 30
 	charge_meter = 0
 	max_shots = 3

code/modules/projectiles/guns/projectile/shotgun.dm

@@ -58,7 +58,7 @@
 	fire_sound = 'sound/weapons/gunshot/gunshot_shotgun2.ogg'
 	is_wieldable = TRUE
 	var/recentpump = 0 // to prevent spammage
-	var/rack_sound = /singleton/sound_category/shotgun_pump
+	var/rack_sound = /decl/sound_category/shotgun_pump
 	var/rack_verb = "pump"
 
 /obj/item/gun/projectile/shotgun/pump/consume_next_projectile()