From 3cd6fcfce90c99a752f69e7b1e0c5897be4eac06 Mon Sep 17 00:00:00 2001
From: Maarten Pronk <git@evetion.nl>
Date: Fri, 20 Dec 2024 17:12:35 +0100
Subject: [PATCH] Add generated, performant snake_case for NodeID.

---
 core/src/parameter.jl | 12 ++++++++++++
 core/src/util.jl      |  6 +++---
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/core/src/parameter.jl b/core/src/parameter.jl
index 072005bf7..6002cc666 100644
--- a/core/src/parameter.jl
+++ b/core/src/parameter.jl
@@ -21,6 +21,17 @@ const SolverStats = @NamedTuple{
     5 Drainage = 6 Precipitation = 7
 Base.to_index(id::Substance.T) = Int(id)  # used to index into concentration matrices
 
+@generated function config.snake_case(nt::NodeType.T)
+    ex = quote end
+    for (sym, _) in EnumX.symbol_map(NodeType.T)
+        sc = QuoteNode(config.snake_case(sym))
+        t = NodeType.T(sym)
+        push!(ex.args, :(nt === $t && return $sc))
+    end
+    push!(ex.args, :(return :nothing))  # type stability
+    ex
+end
+
 # Support creating a NodeType enum instance from a symbol or string
 function NodeType.T(s::Symbol)::NodeType.T
     symbol_map = EnumX.symbol_map(NodeType.T)
@@ -86,6 +97,7 @@ Base.convert(::Type{Int32}, id::NodeID) = id.value
 Base.broadcastable(id::NodeID) = Ref(id)
 Base.:(==)(id_1::NodeID, id_2::NodeID) = id_1.type == id_2.type && id_1.value == id_2.value
 Base.show(io::IO, id::NodeID) = print(io, id.type, " #", id.value)
+config.snake_case(id::NodeID) = config.snake_case(id.type)
 
 function Base.isless(id_1::NodeID, id_2::NodeID)::Bool
     if id_1.type != id_2.type
diff --git a/core/src/util.jl b/core/src/util.jl
index e9c2a2bcc..2ae1dbeff 100644
--- a/core/src/util.jl
+++ b/core/src/util.jl
@@ -657,7 +657,7 @@ function get_variable_ref(
                 PreallocationRef(cache(1), flow_idx; from_du = true)
             end
         else
-            node = getfield(p, snake_case(Symbol(node_id.type)))
+            node = getfield(p, snake_case(node_id))
             PreallocationRef(node.flow_rate, node_id.idx)
         end
     else
@@ -814,7 +814,7 @@ function collect_control_mappings!(p)::Nothing
 
     for node_type in instances(NodeType.T)
         node_type == NodeType.Terminal && continue
-        node = getfield(p, Symbol(snake_case(string(node_type))))
+        node = getfield(p, snake_case(node_type))
         if hasfield(typeof(node), :control_mapping)
             control_mappings[node_type] = node.control_mapping
         end
@@ -1096,7 +1096,7 @@ function get_state_index(
     component_name = if id.type == NodeType.UserDemand
         inflow ? :user_demand_inflow : :user_demand_outflow
     else
-        snake_case(Symbol(id.type))
+        snake_case(id)
     end
     for (comp, range) in pairs(NT)
         if comp == component_name