Conversion koans

koans/ConversionKoans.jl

@@ -1,2 +1,55 @@
 module ConversionKoans
-end
+
+#=
+    Conversion allows to apply methods defined for the converted type.
+    Here is the basic documentation for conversion and promotion in Julia:
+        -https://docs.julialang.org/en/v1/manual/conversion-and-promotion/
+=#
+
+struct MyTypeComplex
+           real::Float64
+           imaginary::Float64
+       end
+
+struct YourType
+       end
+
+function type_of(x)
+    #=
+     The type of a variable is one of its most important features,
+     so we want to have this information at hand.
+     Write a function returning the type of x.
+     Ex: x = 3.6 return Float64.
+    =#
+end
+
+function int_to_float64(int)
+    #=
+     Converting from one type to another is a common operation,
+     for example, converting a variable of type int to type float.
+     Write a function converting the variable "int" to Float64.
+     Ex: int = 4; return 4.0
+    =#
+end
+
+function define_YourType(int, float)
+    #=
+     Sometimes defining a custom type allow you to create representations
+     with some useful properties, as defining a complex number type as MyTypeComplex,
+     defined above.
+     Define a type YourType, it receives an Int64 and a Float64
+    =#
+end
+
+function convertion_vector_to_MyTypeComplex(vec)
+    #=
+     The conversion function allow you to define the conversion
+     behaviour between types.
+     Define the conversion, from vec[::Float64, ::Float64] to
+     MyType defined above to use the function convert a return the
+     conversion of vec.
+     Ex: convert(MyTypeComplex, vec)
+    =#
+end
+
+end

solutions/ConversionKoans.jl

@@ -0,0 +1,71 @@
+module ConversionKoans
+
+
+#=
+    Conversion allows to apply methods defined for the converted type.
+    Here is the basic documentation for conversion and promotion in Julia:
+        -https://docs.julialang.org/en/v1/manual/conversion-and-promotion/
+=#
+
+struct MyTypeComplex
+            real::Float64
+            imaginary::Float64
+       end
+
+struct YourType
+            a::Int64
+            b::Float64
+       end
+
+function type_of(x)
+    #=
+     The type of a variable is one of its most important features,
+     so we want to have this information at hand.
+     Write a function returning the type of x.
+     Here is the link to the documentation:
+      - http://www.jlhub.com/julia/manual/en/function/typeof
+     Ex: x = 3.6; return Float64.
+    =#
+    return typeof(x)
+end
+
+function int_to_float64(int)
+    #=
+     Converting from one type to another is a common operation,
+     for example, converting a variable of type int to type float.
+     Write a function converting the variable "int" to Float64.
+     Here is the link to the function used:
+     - http://www.jlhub.com/julia/manual/en/function/convert
+     Ex: int = 4; return 4.0
+    =#
+    return convert(Float64, int)
+end
+
+function define_YourType(int, float)
+    #=
+     Sometimes defining a custom type allow you to create representations
+     with some useful properties, as defining a complex number type as MyTypeComplex,
+     defined above.
+     Define a type YourType, it receives an Int64 and a Float64
+     Here is some useful information regarding defining types:
+      - https://docs.julialang.org/en/v1/manual/types/#Composite-Types
+    =#
+    return YourType(int, float)
+end
+
+function convertion_vector_to_MyTypeComplex(vec)
+    #=
+     The conversion function allow you to define the conversion
+     behaviour between types.
+     Define the conversion, from vec[::Float64, ::Float64] to
+     MyType defined above to use the function convert
+     Here is the link to some useful information about custom conversion
+     functions in Julia:
+      - https://docs.julialang.org/en/v1/manual/conversion-and-promotion/#Defining-New-Conversions
+     Ex: convert(MyTypeComplex, vec)
+    =#
+    convert(::Type{MyTypeComplex}, x) = MyTypeComplex(x[1],x[2])
+    return convert(MyTypeComplex, vec)
+end
+
+end

tests/solutions/tests_solutions.jl

@@ -48,9 +48,18 @@ end
 # @testset "Strings" begin
 # end
 
-# using ConversionKoans
-# @testset "Type Conversions" begin
-# end
+using ConversionKoans
+@testset "Conversion operations" begin
+    @test ConversionKoans.type_of(4) == Int64
+    @test ConversionKoans.type_of([3, 4]) == Array{Int64,1}
+    @test ConversionKoans.type_of(3.5 + im) == Complex{Float64}
+    @test ConversionKoans.int_to_float64(3) == 3.0
+    @test ConversionKoans.int_to_float64(20) == 20.0
+    @test typeof(ConversionKoans.convertion_vector_to_MyTypeComplex([5,6])) == ConversionKoans.MyTypeComplex
+    @test typeof(ConversionKoans.convertion_vector_to_MyTypeComplex([-10.1,5.4])) == ConversionKoans.MyTypeComplex
+    @test typeof(ConversionKoans.define_YourType(1, 2.2)) == ConversionKoans.YourType
+    @test typeof(ConversionKoans.define_YourType(1, -3.0)) == ConversionKoans.YourType
+end
 
 # using ArrayKoans
 # @testset "Arrays" begin

tests/tests.jl

@@ -49,7 +49,16 @@ using StringKoans
 end
 
 using ConversionKoans
-@testset "Type Conversions" begin
+@testset "Conversion operations" begin
+    @test ConversionKoans.type_of(4) == Int64
+    @test ConversionKoans.type_of([3, 4]) == Array{Int64,1}
+    @test ConversionKoans.type_of(3.5 + im) == Complex{Float64}
+    @test ConversionKoans.int_to_float64(3) == 3.0
+    @test ConversionKoans.int_to_float64(20) == 20.0
+    @test typeof(ConversionKoans.convertion_vector_to_MyTypeComplex([5,6])) == ConversionKoans.MyTypeComplex
+    @test typeof(ConversionKoans.convertion_vector_to_MyTypeComplex([-10.1,5.4])) == ConversionKoans.MyTypeComplex
+    @test typeof(ConversionKoans.define_YourType(1, 2.2)) == ConversionKoans.YourType
+    @test typeof(ConversionKoans.define_YourType(1, -3.0)) == ConversionKoans.YourType
 end
 
 using ArrayKoans