move 'isolderthan' and 'findfreeslot' back to queries.jl'

src/ProtocolZoo/utils.jl

@@ -22,51 +22,6 @@ function findswapablequbits(net, node, pred_low, pred_high, choose_low, choose_h
     return (low_nodes[il], high_nodes[ih])
 end
 
-"""Find an empty unlocked slot in a given [`Register`](@ref).
-
-```jldoctest
-julia> reg = Register(3); initialize!(reg[1], X); lock(reg[2]);
-
-julia> findfreeslot(reg) == reg[3]
-true
-
-julia> lock(findfreeslot(reg));
-
-julia> findfreeslot(reg) |> isnothing
-true
-```
-"""
-function findfreeslot(reg::Register; randomize=false, margin=0)
-    n_slots = length(reg.staterefs)
-    freeslots = sum((!isassigned(reg[i]) for i in 1:n_slots))
-    if freeslots >= margin
-        perm = randomize ? randperm : (x->1:x)
-        for i in perm(n_slots)
-            slot = reg[i]
-            islocked(slot) || isassigned(slot) || return slot
-        end
-    end
-end
-
-
-struct NotAssignedError <: Exception # TODO use this in all places where we are throwing something on isassigned (maybe rename to IsAssignedError and check whether we need to keep `f` as part of it (might already be provided by the stacktrace) and check it does not allocate even when the error is not triggered)
-    msg
-    f
-end
-
-function Base.showerror(io::IO, err::NotAssignedError)
-    print(io, "NotAssignedError: ")
-    println(io, err.msg)
-    println("In function: $(err.f)")
-end
-
-"""Check whether a qubit has existed for a time more than its cutoff/coherence time"""
-function isolderthan(slot::RegRef, time_left::Float64)
-    if !isassigned(slot) throw(NotAssignedError("Slot must be assigned with a quantum state before checking coherence.", isolderthan)) end
-    id = query(slot, QuantumSavory.ProtocolZoo.EntanglementCounterpart, ❓, ❓).id
-    slot_time  = slot.reg.tag_info[id][3]
-    return (now(get_time_tracker(slot))) - slot_time > time_left
-end
 
 """
 $TYPEDEF

src/queries.jl

@@ -381,6 +381,51 @@ function query(mb::MessageBuffer, query::Tag)
     return nothing
 end
 
+"""Find an empty unlocked slot in a given [`Register`](@ref).
+
+```jldoctest
+julia> reg = Register(3); initialize!(reg[1], X); lock(reg[2]);
+
+julia> findfreeslot(reg) == reg[3]
+true
+
+julia> lock(findfreeslot(reg));
+
+julia> findfreeslot(reg) |> isnothing
+true
+```
+"""
+function findfreeslot(reg::Register; randomize=false, margin=0)
+    n_slots = length(reg.staterefs)
+    freeslots = sum((!isassigned(reg[i]) for i in 1:n_slots))
+    if freeslots >= margin
+        perm = randomize ? randperm : (x->1:x)
+        for i in perm(n_slots)
+            slot = reg[i]
+            islocked(slot) || isassigned(slot) || return slot
+        end
+    end
+end
+
+
+struct NotAssignedError <: Exception # TODO use this in all places where we are throwing something on isassigned (maybe rename to IsAssignedError and check whether we need to keep `f` as part of it (might already be provided by the stacktrace) and check it does not allocate even when the error is not triggered)
+    msg
+    f
+end
+
+function Base.showerror(io::IO, err::NotAssignedError)
+    print(io, "NotAssignedError: ")
+    println(io, err.msg)
+    println("In function: $(err.f)")
+end
+
+"""Check whether a qubit has existed for a time more than its cutoff/coherence time"""
+function isolderthan(slot::RegRef, time_left::Float64)
+    if !isassigned(slot) throw(NotAssignedError("Slot must be assigned with a quantum state before checking coherence.", isolderthan)) end
+    id = query(slot, QuantumSavory.ProtocolZoo.EntanglementCounterpart, ❓, ❓).id
+    slot_time  = slot.reg.tag_info[id][3]
+    return (now(get_time_tracker(slot))) - slot_time > time_left
+end
 
 function Base.isassigned(r::Register,i::Int) # TODO erase
     r.stateindices[i] != 0 # TODO this also usually means r.staterefs[i] !== nothing - choose one and make things consistent