From 1c9c85cea635f8e3681ab4e9a14a80a2cf42002d Mon Sep 17 00:00:00 2001
From: Datseris <datseris.george@gmail.com>
Date: Tue, 20 Feb 2024 23:23:00 +0000
Subject: [PATCH] add convert_to_parameters macro

---
 docs/src/index.md      |  1 +
 src/processes_basic.jl |  2 +-
 src/utils.jl           | 50 ++++++++++++++++++++++++++----------------
 test/runtests.jl       | 14 ++++++++++++
 4 files changed, 47 insertions(+), 20 deletions(-)

diff --git a/docs/src/index.md b/docs/src/index.md
index c9b048a..4120891 100644
--- a/docs/src/index.md
+++ b/docs/src/index.md
@@ -178,4 +178,5 @@ ProcessBasedModelling.lhs
 default_value
 has_variable
 new_derived_named_parameter
+convert_to_parameters
 ```
diff --git a/src/processes_basic.jl b/src/processes_basic.jl
index f3f7d23..3c9379f 100644
--- a/src/processes_basic.jl
+++ b/src/processes_basic.jl
@@ -3,7 +3,7 @@
 
 The simplest process which equates a given `variable` to a constant value
 that is encapsulated in a parameter. If `value isa Real`, then
-hence, a named parameter with the name of `variable` and `_0` appended is created.
+a named parameter with the name of `variable` and `_0` appended is created.
 Else, if `valua isa Num` then it is taken as the paremeter directly.
 
 Example:
diff --git a/src/utils.jl b/src/utils.jl
index 169f39a..73b165f 100644
--- a/src/utils.jl
+++ b/src/utils.jl
@@ -68,28 +68,40 @@ function new_derived_named_parameter(newstring::String, value::Real)
     return first(dummy)
 end
 
+# Macro thanks to Jonas Isensee,
+# https://discourse.julialang.org/t/metaprogramming-macro-calling-another-macro-making-named-variables/109621/6
 """
-    @named_parameters vars...
+    @convert_to_parameters vars...
 
-Convert all Julia variables `vars` into `@parameters` with name the same as `vars`
-and default value the same as the value of `vars`.
+Convert all variables `vars` into `@parameters` with name the same as `vars`
+and default value the same as the value of `vars`. Example:
+
+```
+julia> A, B = 0.5, 0.5
+(0.5, 0.5)
+
+julia> @convert_to_parameters A B
+2-element Vector{Num}:
+ A
+ B
+
+julia> typeof(A) # `A` is not a number anymore!
+Num
+
+julia> default_value(A)
+0.5
 """
-macro named_parameters(vars...)
-    return quote
-        out = []
-        for v in vars
-            res = (ModelingToolkit.toparam)((Symbolics.wrap)((Symbolics.SymbolicUtils.setmetadata)((Symbolics.setdefaultval)((Sym){Real}($(QuoteNode(v))), $(esc(v))), Symbolics.VariableSource, (:parameters, $(QuoteNode(v))))))
-            push!(out, res)
-        end
-        $(out...)
+macro convert_to_parameters(vars...)
+    expr = Expr(:block)
+    for var in vars
+        binding = esc(var)
+        varname = QuoteNode(var)
+        push!(expr.args,
+            :($binding = (ModelingToolkit.toparam)((Symbolics.wrap)((SymbolicUtils.setmetadata)((Symbolics.setdefaultval)((Sym){Real}($varname), $binding), Symbolics.VariableSource, (:parameters, $varname)))))
+            )
     end
+    push!(expr.args, Expr(:vect, esc.(vars)...))
+    return expr
 end
 
-# This may help:
-
-# julia> @macroexpand @parameters A=0.1 B=0.1
-# quote
-#     A = (ModelingToolkit.toparam)((Symbolics.wrap)((SymbolicUtils.setmetadata)((Symbolics.setdefaultval)((Sym){Real}(:A), 0.1), Symbolics.VariableSource, (:parameters, :A))))
-#     B = (ModelingToolkit.toparam)((Symbolics.wrap)((SymbolicUtils.setmetadata)((Symbolics.setdefaultval)((Sym){Real}(:B), 0.1), Symbolics.VariableSource, (:parameters, :B))))
-#     [A, B]
-# end
\ No newline at end of file
+export @convert_to_parameters
diff --git a/test/runtests.jl b/test/runtests.jl
index 3662263..d383ec0 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -112,3 +112,17 @@ end
 @testset "extending default processes" begin
     # API not yet finished on this one
 end
+
+@testset "utility functions" begin
+    @variables x(t) = 0.5
+    p = new_derived_named_parameter(x, 0.2, "t")
+    @test ModelingToolkit.getname(p) == :x_t
+    @test default_value(p) == 0.2
+    p = new_derived_named_parameter(x, p, "lala")
+    @test ModelingToolkit.getname(p) == :x_t
+
+    A, B = 0.5, 0.5
+    @convert_to_parameters A B
+    @test A isa Num
+    @test default_value(A) == 0.5
+end