Fix for dimensionless units

src/readsbml.jl

@@ -177,7 +177,7 @@ function extractModel(mdl::VPtr)::SBML.Model
     end
 
     # parse out the unit definitions
-    units = Dict{String,Quantity}()
+    units = Dict{String,Number}()
     for i = 1:ccall(sbml(:Model_getNumUnitDefinitions), Cuint, (VPtr,), mdl)
         ud = ccall(sbml(:Model_getUnitDefinition), VPtr, (VPtr, Cuint), mdl, i - 1)
         id = get_string(ud, :UnitDefinition_getId)

src/structs.jl

@@ -160,7 +160,7 @@ objects.
 """
 struct Model
     parameters::Dict{String,Float64}
-    units::Dict{String,Quantity}
+    units::Dict{String,Number}
     compartments::Dict{String,Compartment}
     species::Dict{String,Species}
     reactions::Dict{String,Reaction}

test/data/units.xml

+<?xml version='1.0' encoding='UTF-8'?>
+<sbml xmlns:fbc="http://www.sbml.org/sbml/level3/version1/fbc/version2" xmlns="http://www.sbml.org/sbml/level3/version1/core" level="3" version="1" sboTerm="SBO:0000624" fbc:required="false">
+  <model fbc:strict="true" id="e_coli_core">
+    <listOfUnitDefinitions>
+      <unitDefinition id="non_existent">
+        <listOfUnits>
+          <unit kind="blahblah" scale="-3" multiplier="3.14" exponent="1"/>
+        </listOfUnits>
+      </unitDefinition>
+      <unitDefinition id="no_dimensions">
+        <listOfUnits>
+          <unit kind="dimensionless" scale="3" multiplier="0.001" exponent="1"/>
+          <unit kind="item" scale="1" multiplier="2" exponent="1"/>
+        </listOfUnits>
+      </unitDefinition>
+    </listOfUnitDefinitions>
+  </model>
+</sbml>

test/loadmodels.jl

@@ -98,6 +98,10 @@ end
     @test m.units["volume"] == 1 * u"L"
     @test m.units["time"] == 1 * u"s"
     @test m.units["substance"] == 1 * u"mol"
+
+    m = readSBML(joinpath(@__DIR__, "data", "units.xml"))
+    @test m.units["non_existent"] == 0.00314
+    @test m.units["no_dimensions"] == 20.0
 end
 
 @testset "Initial amounts and concentrations" begin