[ADD] promotion and conversion in julia

10_ConversionPromotion.jl

@@ -0,0 +1,61 @@
+function foobar(a,b)
+    x::Int8 = a
+    y::Int8 = b
+    return x+y      
+end
+
+println(foobar(1,2))
+
+println(typeof(foobar(1,2)))
+
+#println(foobar("1","2"))
+
+println(Int8(4))
+
+#println(Int8("4"))
+
+println(isa(2,Int64))
+
+println(isa(2,Float64))
+
+println(isa(2,Integer))
+
+println(isa(Int8,DataType))
+
+println(isa(Int8,Type{Int8}))
+
+println(isa(Int8,Type{Int16}))
+
+println(convert(Int8,4))
+
+println(typeof(convert(Int8,4)))
+
+# convert(::Type{Int8}, x::Int64) = 
+
+Base.convert(::Type{Int8}, x::String) = parse(Int8,x)
+
+println(foobar("1","2"))
+
+println(Int8("4"))
+
+println(1+2.0+Int8(3))
+
+println(typeof(1+2.0+Int8(3)))
+
+println(promote(1,2.0,Int8(3)))
+
+a = promote(1,2.0,Int8(3))
+
+println(+(a...)) # ... tuple unpacker
+
+b = (3,2)
+
+println(+(b...))
+
+println(promote(Int8(2),Int16(4)))
+
+c = promote(Int8(2),Int16(4))
+
+println(typeof(c))
+
+@edit 2+4