Add Base.print(::IO, ::Index)

This allows the user to turn an `Index` into a string easily, and also makes it
easier to test the indices.

src/fasta/index.jl

@@ -209,6 +209,12 @@ function Base.write(io::IO, index::Index)
     n
 end
 
+function Base.print(io::IO, index::Index)
+    buffer = IOBuffer()
+    write(buffer, index)
+    String(take!(buffer))
+end
+
 index_fasta_actions = Dict(
     :mark => :(@mark),
     :countline => :(linenum += 1),
@@ -357,4 +363,4 @@ function faidx(fnapath::AbstractString, faidxpath::AbstractString; check::Bool=t
     index
 end
 
-faidx(path::AbstractString; check::Bool=true) = faidx(path, path * ".fai"; check=check)
+faidx(path::AbstractString; check::Bool=true) = faidx(path, path * ".fai"; check=check)

test/fasta/index.jl

@@ -24,6 +24,7 @@ function test_same_index(a::Index, b::Index)
     @test a.lengths == b.lengths
     @test a.offsets == b.offsets
     @test a.encoded_linebases == b.encoded_linebases
+    @test string(a) == string(b)
 end
 
 @testset "Parsing index" begin
@@ -253,4 +254,4 @@ UUGC
     @test extract(reader, "seq1", 3:5) == "GAA"
 end
 
-end # testset Index
+end # testset Index