Replace OrderedSet with Dict{Symbolic, Int}

Author: bowenszhu

Project.toml

@@ -7,7 +7,6 @@ version = "0.1.0"
 DocStringExtensions = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 ModelingToolkit = "961ee093-0014-501f-94e3-6117800e7a78"
-OrderedCollections = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
 RandomizedLinAlg = "0448d7d9-159c-5637-8537-fd72090fea46"
 Setfield = "efcf1570-3423-57d1-acb7-fd33fddbac46"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
@@ -18,7 +17,6 @@ TSVD = "9449cd9e-2762-5aa3-a617-5413e99d722e"
 [compat]
 DocStringExtensions = "0.8"
 ModelingToolkit = "8.21"
-OrderedCollections = "1.4"
 RandomizedLinAlg = "0.1"
 Setfield = "0.8, 1"
 SymbolicUtils = "0.19"

src/utils.jl

@@ -1,4 +1,4 @@
-using OrderedCollections, SparseArrays
+using SparseArrays
 
 """
 $(TYPEDSIGNATURES)
@@ -35,12 +35,16 @@ where the constant terms do not contain any variables in `vars`.
 Variables in `vars` must be unique.
 """
 function linear_terms(exprs::AbstractVector, vars)
-    vars = OrderedSet(Symbolics.unwrap.(vars))
+    vars = Symbolics.unwrap.(vars)
     exprs = Symbolics.unwrap.(exprs)
     linear_I = Int[] # row idx for sparse matrix
     linear_J = Int[] # col idx for sparse matrix
     linear_V = Float64[] # values
     idxmap = Dict(v => i for (i, v) in enumerate(vars))
+    if length(idxmap) < length(vars)
+        throw(ArgumentError("vars: $vars are not unique"))
+    end
+    vars = keys(idxmap)
 
     # (a function used to avoid code duplication)
     # when a linear term is identified, add the indices and value to the sparse matrix