Merge pull request 'Added function Input.getEnum(string, enum_type)' (#1) from check-enum-type into master

Reviewed-on: #1

src/Input.jl

@@ -643,4 +643,30 @@ function inputSettings(settingsDirectory::String)
     return settings
 end # function inputSettings
 
+"""
+    getEnum(string, enum_type)
+
+Converts a string to an enumerated type.
+But only if the string matches an enumerated value.
+
+# Example
+```jldoctest
+julia> @enum trainTypes passenger freight
+
+julia> myTrain = "passenger"
+"passenger"
+
+julia> myTrainType = getEnum(myTrain, trainTypes)
+passenger::trainTypes = 0
+```
+"""
+function getEnum(string::String, enum_type::DataType)
+    inst   = instances(enum_type)  # get all instances of enumerated type
+    syms   = Symbol.(inst)         # convert all instances to Symbols
+    lookup = Dict(zip(syms, inst)) # combine instances and Symbols in a lookup table
+    #
+    n_str  = Symbol(string)        # normalize String via a Symbol
+    return lookup[n_str]           # return matched enumerated type
+end # function getEnum
+
 end # module Input

test/testEnums.jl

@@ -0,0 +1,24 @@
+#!/usr/bin/env julia
+# -*- coding: UTF-8 -*-
+# __julia-version__ = 1.7.0
+# __author__        = "Martin Scheidt"
+# __copyright__     = "2021"
+# __license__       = "ISC"
+
+include("../src/types.jl")
+include("../src/Input.jl")
+
+using .Input
+using YAML, Test
+
+@enum trainTypes passenger=1 freight=2 motorCoachTrain=3
+
+@test Input.getEnum("passenger", trainTypes)       == passenger::trainTypes
+@test Input.getEnum("freight", trainTypes)         == freight::trainTypes
+@test Input.getEnum("motorCoachTrain", trainTypes) == motorCoachTrain::trainTypes
+
+data = YAML.load(open("data/trains/train_passenger_IC2.yaml"))
+@test Input.getEnum(data["train"]["trainType"], trainTypes) == passenger::trainTypes
+
+data = YAML.load(open("data/trains/train_freight_V90withOreConsist.yaml"))
+@test Input.getEnum(data["train"]["trainType"], trainTypes) == freight::trainTypes