From 0fbf08ef9587c885ca97845f7ad19cb6d14e4555 Mon Sep 17 00:00:00 2001
From: Jukka Aho <ahojukka5@gmail.com>
Date: Sat, 9 May 2026 18:14:40 +0300
Subject: [PATCH] chore(physics): delete unused formulation trait stubs

Remove the superseded formulation tagging layer not included from `JuliaFEM.jl`.

- Drop `src/physics/formulations.jl`.
---
 src/physics/formulations.jl | 87 -------------------------------------
 1 file changed, 87 deletions(-)
 delete mode 100644 src/physics/formulations.jl

diff --git a/src/physics/formulations.jl b/src/physics/formulations.jl
deleted file mode 100644
index be647e4..0000000
--- a/src/physics/formulations.jl
+++ /dev/null
@@ -1,87 +0,0 @@
-# This file is a part of JuliaFEM.
-# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
-
-"""
-Helper utilities for multi-field microkernel assembly.
-
-Works with existing Element{K,P,S} system where S is a NamedTuple specifying fields.
-
-# Philosophy
-
-Element{K,P,S} encodes everything:
-- K: Topology (Triangle, Tetrahedron, etc.)
-- P: Basis (Lagrange{1}, Lagrange{2}, etc.)
-- S: NamedTuple of fields with types and entity locations
-
-# Example
-
-```julia
-# Thermoelasticity using Element{K,P,S} directly:
-S = @DOFSet{T::DOF{Temperature,Vertex}, u::DOF{Displacement{3},Vertex}}
-elem = Element{Tet4, Lagrange{1}, S}(id, dof_indices)
-
-# Extract field info (compile-time!):
-field_names = fieldnames(S)  # (:T, :u)
-range_T = field_dof_range(elem, :T)  # Compile-time range
-```
-"""
-
-using ..JuliaFEM: AbstractField, Displacement, Temperature
-
-# ============================================================================
-# FIELD TYPE EXTRACTION FROM S (Element{K,P,S})
-# ============================================================================
-
-"""
-    field_type_for_dispatch(S, field_name::Symbol)
-
-Extract field type from Element's S parameter for dispatch.
-
-Works at runtime with NamedTuple-based field specifications.
-
-# Example
-```julia
-S = @DOFSet{T::DOF{Temperature,Vertex}, u::DOF{Displacement{3},Vertex}}
-field_type_for_dispatch(S, :T)  # Temperature()
-field_type_for_dispatch(S, :u)  # Displacement{3}()
-```
-"""
-function field_type_for_dispatch(::Type{S}, field_name::Symbol) where S<:DOFSet
-    # Get field names at runtime
-    names = fieldnames(S)
-    idx = findfirst(==(field_name), names)
-    isnothing(idx) && error("Field $field_name not found in $S")
-    
-    # Get the type of that field
-    field_tuple_type = fieldtype(S, idx)
-    
-    # field_tuple_type should be DOF{FieldType, EntityType}
-    # Extract the FieldType (first element)
-    FieldType = field_tuple_type.parameters[1]
-    
-    # FieldType must be a field type (AbstractField)
-    if FieldType <: AbstractField
-        # Create an instance of the field type
-        return FieldType()
-    else
-        error("Expected field type (AbstractField) in DOF, got $FieldType. Use format: DOF{FieldType, EntityType} where FieldType <: AbstractField")
-    end
-end
-
-# ============================================================================
-# CONVENIENCE TYPE ALIASES (for documentation/examples)
-# ============================================================================
-
-"""
-    ThermoelasticityFields
-
-Type alias for common thermoelasticity field specification.
-Use as Element{K, P, ThermoelasticityFields} type parameter.
-
-# Example
-```julia
-const ThermoelasticityFields = @DOFSet{T::DOF{Temperature,Vertex}, u::DOF{Displacement{3},Vertex}}
-elem = Element{Tet4, Lagrange{1}, ThermoelasticityFields}(id, dofs)
-```
-"""
-const ThermoelasticityFields = @DOFSet{T::DOF{Temperature,Vertex}, u::DOF{Displacement{3},Vertex}}