From 0754245539ce65850bc35d26b32fcd208c6a11e1 Mon Sep 17 00:00:00 2001
From: Jakob Nybo Nissen <jakobnybonissen@gmail.com>
Date: Sun, 28 Feb 2021 14:20:37 +0100
Subject: [PATCH 1/2] Add quality iterator

---
 src/fastq/record.jl | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/fastq/record.jl b/src/fastq/record.jl
index c8056eb..3a1189d 100644
--- a/src/fastq/record.jl
+++ b/src/fastq/record.jl
@@ -300,21 +300,27 @@ end
 "Get the length of the fastq record's sequence."
 @inline seqlen(record::Record) = last(record.sequence) - first(record.sequence) + 1
 
+"""
+    quality_iter(record::Record, [offset::Integer=33, [part::UnitRange]])::Vector{UInt8}
+
+Get an iterator of base quality of `record`. This iterator is corrupted if the record is mutated.
+"""
+function quality_iter(record::Record, offset::Integer=33, part::UnitRange{Int}=1:lastindex(record.quality))
+    checkfilled(record)
+    offs = convert(UInt8, offset)
+    part = record.quality[part]
+    data = record.data
+    return (@inbounds(data[i]) - offs for i in part)
+end
+
 """
     quality(record::Record, [offset::Integer=33, [part::UnitRange]])::Vector{UInt8}
 
 Get the base quality of `record`.
 """
 function quality(record::Record, offset::Integer=33, part::UnitRange{Int}=1:lastindex(record.quality))::Vector{UInt8}
-    checkfilled(record)
-    quality = record.data[record.quality[part]]
-    for i in 1:lastindex(part)
-        # TODO: Checked arithmetic?
-        @inbounds quality[i] -= offset
-    end
-    return quality
+    collect(quality_iter(record, offset, part))
 end
-
 """
     quality(record::Record, encoding_name::Symbol, [part::UnitRange])::Vector{UInt8}
 

From 6b0f588dfdcd760627574074ae38b22966c1a0b4 Mon Sep 17 00:00:00 2001
From: Jakob Nybo Nissen <jakobnybonissen@gmail.com>
Date: Sun, 28 Feb 2021 14:46:15 +0100
Subject: [PATCH 2/2] Add sequence iterator

---
 src/fasta/fasta.jl  |  1 +
 src/fasta/record.jl | 15 +++++++++++++++
 src/fastq/record.jl | 15 +++++++++++++++
 test/runtests.jl    |  6 +++++-
 4 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/fasta/fasta.jl b/src/fasta/fasta.jl
index c34f44a..c9f81f3 100644
--- a/src/fasta/fasta.jl
+++ b/src/fasta/fasta.jl
@@ -10,6 +10,7 @@ import BioGenerics: BioGenerics, isfilled
 import BioGenerics.Exceptions: missingerror
 import BioGenerics.Automa: State
 import BioSequences
+import BioSymbols
 import TranscodingStreams: TranscodingStreams, TranscodingStream
 import ..FASTX: identifier, description, sequence
 
diff --git a/src/fasta/record.jl b/src/fasta/record.jl
index 51885a9..bb42183 100644
--- a/src/fasta/record.jl
+++ b/src/fasta/record.jl
@@ -212,6 +212,21 @@ function header(record::Record)
     return String(record.data[range])
 end
 
+"""
+    sequence_iter(T, record::Record)
+
+Yields an iterator of the sequence, with elements of type `T`. `T` is constructed
+through `T(Char(x))` for each byte `x`. E.g. `sequence_iter(DNA, record)`.
+Mutating the record will corrupt the iterator.
+"""
+function sequence_iter(::Type{T}, record::Record,
+    part::UnitRange{<:Integer}=1:lastindex(record.sequence)) where {T <: BioSymbols.BioSymbol}
+    checkfilled(record)
+    seqpart = record.sequence[part]
+    data = record.data
+    return (T(Char(@inbounds (data[i]))) for i in seqpart)
+end
+
 """
     sequence(::Type{S}, record::Record, [part::UnitRange{Int}])::S
 
diff --git a/src/fastq/record.jl b/src/fastq/record.jl
index 3a1189d..35e7df3 100644
--- a/src/fastq/record.jl
+++ b/src/fastq/record.jl
@@ -240,6 +240,21 @@ function Base.copyto!(dest::BioSequences.LongSequence, doff, src::Record, soff,
     return copyto!(dest, doff, src.data, src.sequence[soff], N)
 end
 
+"""
+    sequence_iter(T, record::Record)
+
+Yields an iterator of the sequence, with elements of type `T`. `T` is constructed
+through `T(Char(x))` for each byte `x`. E.g. `sequence_iter(DNA, record)`.
+Mutating the record will corrupt the iterator.
+"""
+function sequence_iter(::Type{T}, record::Record,
+    part::UnitRange{<:Integer}=1:lastindex(record.sequence)) where {T <: BioSymbols.BioSymbol}
+    checkfilled(record)
+    seqpart = record.sequence[part]
+    data = record.data
+    return (T(Char(@inbounds (data[i]))) for i in seqpart)
+end
+
 """
     sequence(::Type{S}, record::Record, [part::UnitRange{Int}])
 
diff --git a/test/runtests.jl b/test/runtests.jl
index 6836077..38fd123 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,6 +1,7 @@
 using Test
 using FASTX
 using FormatSpecimens
+using BioSymbols
 import BioGenerics
 import BioGenerics.Testing: intempdir
 import BioSequences:
@@ -35,7 +36,8 @@ import BioSequences:
         @test BioGenerics.hassequence(record)
         @test FASTA.hassequence(record)
         @test FASTA.sequence(record) == dna"ACGT"
-        @test FASTA.sequence(record, 2:3) == dna"CG"
+        @test collect(FASTA.sequence_iter(DNA, record)) == [DNA_A, DNA_C, DNA_G, DNA_T] 
+        @test FASTA.sequence(record, 2:3) == LongDNASeq(collect(FASTA.sequence_iter(DNA, record, 2:3))) == dna"CG"
         @test FASTA.sequence(String, record) == "ACGT"
         @test FASTA.sequence(String, record, 2:3) == "CG"
 
@@ -331,6 +333,8 @@ end
         @test FASTQ.header(record) == FASTQ.identifier(record) * " " * FASTA.description(record)
         @test FASTQ.hassequence(record) == BioGenerics.hassequence(record) == true
         @test FASTQ.sequence(LongDNASeq, record) == seq
+        @test LongDNASeq(collect(FASTQ.sequence_iter(DNA, record))) == seq
+        @test LongDNASeq(collect(FASTQ.sequence_iter(DNA, record, 3:7))) == dna"GCTCA"
         @test copyto!(LongDNASeq(FASTQ.seqlen(record)), record) == seq
         @test_throws ArgumentError copyto!(LongDNASeq(10), FASTQ.Record())
         @test FASTQ.sequence(record) == BioGenerics.sequence(record) == seq