diff --git a/src/Edit.jl b/src/Edit.jl
new file mode 100644
index 0000000..ecf2094
--- /dev/null
+++ b/src/Edit.jl
@@ -0,0 +1,142 @@
+"""
+    Substitution
+
+Represents the presence of a `T` at a given position. The position is stored
+outside this struct.
+"""
+struct Substitution{T<:BioSymbol}
+    x::T
+end
+Base.:(==)(x::Substitution, y::Substitution) = x.x == y.x
+Base.hash(x::Substitution, h::UInt) = hash(Substitution, hash(x.x, h))
+
+"""
+    Deletion
+
+Represents the deletion of N symbols. The location of the deletion is stored
+outside this struct
+"""
+struct Deletion
+    len::UInt
+
+    function Deletion(len::UInt)
+        iszero(len) && error("Deletion must be at least 1 symbol")
+        return new(len)
+    end
+end
+Deletion(x::Integer) = Deletion(convert(UInt, x))
+Base.length(x::Deletion) = Int(x.len)
+Base.hash(x::Deletion, h::UInt) = hash(Deletion, hash(x.len, h))
+
+"""
+    Insertion{S <: BioSequence}
+
+Represents the insertion of a `S` into a sequence. The location of the insertion
+is stored outside the struct.
+"""
+struct Insertion{S<:BioSequence}
+    seq::S
+
+    function Insertion{S}(x::S) where {S<:BioSequence}
+        isempty(x) && error("Insertion must be at least 1 symbol")
+        return new(x)
+    end
+end
+Insertion(s::BioSequence) = Insertion{typeof(s)}(s)
+Base.length(x::Insertion) = length(x.seq)
+Base.:(==)(x::Insertion, y::Insertion) = x.seq == y.seq
+Base.hash(x::Insertion, h::UInt) = hash(Insertion, hash(x.seq, h))
+
+"""
+    Edit{S <: BioSequence, T <: BioSymbol}
+
+An edit of either `Substitution{T}`, `Insertion{S}` or `Deletion` at a position.
+If deletion: Deletion of length L at ref pos `pos:pos+L-1`
+If insertion: Insertion of length L b/w ref pos `pos:pos+1`
+"""
+struct Edit{S<:BioSequence,T<:BioSymbol}
+    x::Union{Substitution{T},Deletion,Insertion{S}}
+    pos::UInt
+end
+Base.:(==)(e1::Edit, e2::Edit) = e1.pos == e2.pos && e1.x == e2.x
+Base.hash(x::Edit, h::UInt) = hash(Edit, hash((x.x, x.pos), h))
+Base.length(e::Edit) = e isa Substitution ? 1 : length(mutation(e))
+
+function Base.parse(::Type{T}, s::AbstractString) where {T<:Edit{Se,Sy}} where {Se,Sy}
+    return parse(T, String(s))
+end
+
+function Base.parse(::Type{<:Edit{Se,Sy}}, s::Union{String,SubString{String}}) where {Se,Sy}
+    # Either "Δ1-2", "11T" or "G16C"
+    if (m = match(r"^Δ(\d+)-(\d+)$", s); m) !== nothing
+        pos = parse(UInt, m[1])
+        stop = parse(UInt, m[2])
+        stop ≥ pos || throw(ArgumentError("Non-positive deletion length: \"" * s * "\""))
+        Edit{Se,Sy}(Deletion(stop - pos + 1), pos)
+    elseif (m = match(r"^(\d+)([A-Za-z]+)$", s); m) !== nothing
+        pos = parse(UInt, m[1])
+        seq = Se(m[2])
+        Edit{Se,Sy}(Insertion(seq), pos)
+    elseif (m = match(r"^[A-Za-z](\d+)([A-Za-z])$", s); m) !== nothing
+        pos = parse(UInt, m[1])
+        sym = Sy(first(m[2]))
+        Edit{Se,Sy}(Substitution(sym), pos)
+    else
+        throw(ArgumentError("Failed to parse edit \"" * s * '"'))
+    end
+end
+
+mutation(e::Edit) = e.x
+BioGenerics.leftposition(e::Edit) = e.pos
+function BioGenerics.rightposition(e::Edit)
+    if mutation(e) isa Substitution
+        return leftposition(e)
+    elseif mutation(e) isa Insertion
+        return leftposition(e) + 1
+    elseif mutation(e) isa Deletion
+        return leftposition(e) + length(e) - 1
+    else
+        error("Unknown mutation type $(typeof(mutation(e)))")
+    end
+end
+
+function lendiff(edit::Edit)
+    x = edit.x
+    return x isa Substitution ? 0 : (x isa Deletion ? -length(x) : length(x.x))
+end
+
+function _refbases(s::Substitution, reference::S, pos::UInt) where {S<:BioSequence}
+    return S([reference[pos]])
+end
+
+function _altbases(s::Substitution, reference::S, pos::UInt) where {S<:BioSequence}
+    return S([s.x])
+end
+
+function _refbases(d::Deletion, reference::S, pos::UInt) where {S<:BioSequence}
+    if pos == 1
+        return S(reference[UnitRange{Int}(pos, pos + length(d))])
+    else
+        return S(reference[UnitRange{Int}(pos - 1, pos + length(d) - 1)])
+    end
+end
+
+function _altbases(d::Deletion, reference::S, pos::UInt) where {S<:BioSequence}
+    if pos == 1
+        return S([reference[pos + 1]])
+    else
+        return S([reference[pos - 1]])
+    end
+end
+
+function _refbases(i::Insertion, reference::S, pos::UInt) where {S<:BioSequence}
+    return S([reference[pos]])
+end
+
+function _altbases(i::Insertion, reference::S, pos::UInt) where {S<:BioSequence}
+    if pos == 1
+        return S([i.seq..., reference[pos]])
+    else
+        return S([reference[pos], i.seq...])
+    end
+end
diff --git a/src/SequenceVariation.jl b/src/SequenceVariation.jl
index 44acddd..25f5260 100644
--- a/src/SequenceVariation.jl
+++ b/src/SequenceVariation.jl
@@ -31,107 +31,7 @@ const BS = BioSequences
 struct Unsafe end
 struct Inapplicable end
 
-"""
-    Substitution
-
-Represents the presence of a `T` at a given position. The position is stored
-outside this struct.
-"""
-struct Substitution{T <: BioSymbol}
-    x::T
-end
-Base.:(==)(x::Substitution, y::Substitution) = x.x == y.x
-Base.hash(x::Substitution, h::UInt) = hash(Substitution, hash(x.x, h))
-
-"""
-    Deletion
-
-Represents the deletion of N symbols. The location of the deletion is stored
-outside this struct
-"""
-struct Deletion
-    len::UInt
-
-    function Deletion(len::UInt)
-        iszero(len) && error("Deletion must be at least 1 symbol")
-        new(len)
-    end
-end
-Deletion(x::Integer) = Deletion(convert(UInt, x))
-Base.length(x::Deletion) = Int(x.len)
-Base.hash(x::Deletion, h::UInt) = hash(Deletion, hash(x.len, h))
-
-"""
-    Insertion{S <: BioSequence}
-
-Represents the insertion of a `S` into a sequence. The location of the insertion
-is stored outside the struct.
-"""
-struct Insertion{S <: BioSequence}
-    seq::S
-
-    function Insertion{S}(x::S) where {S <: BioSequence}
-        isempty(x) && error("Insertion must be at least 1 symbol")
-        new(x)
-    end
-end
-Insertion(s::BioSequence) = Insertion{typeof(s)}(s)
-Base.length(x::Insertion) = length(x.seq)
-Base.:(==)(x::Insertion, y::Insertion) = x.seq == y.seq
-Base.hash(x::Insertion, h::UInt) = hash(Insertion, hash(x.seq, h))
-
-"""
-    Edit{S <: BioSequence, T <: BioSymbol}
-
-An edit of either `Substitution{T}`, `Insertion{S}` or `Deletion` at a position.
-If deletion: Deletion of length L at ref pos `pos:pos+L-1`
-If insertion: Insertion of length L b/w ref pos `pos:pos+1`
-"""
-struct Edit{S <: BioSequence, T <: BioSymbol}
-    x::Union{Substitution{T}, Deletion, Insertion{S}}
-    pos::UInt
-end
-Base.:(==)(e1::Edit, e2::Edit) = e1.pos == e2.pos && e1.x == e2.x
-Base.hash(x::Edit, h::UInt) = hash(Edit, hash((x.x, x.pos), h))
-Base.length(e::Edit) = e isa Substitution ? 1 : length(mutation(e))
-
-function Base.parse(::Type{T}, s::AbstractString) where {T <: Edit{Se, Sy}}  where {Se, Sy}
-    parse(T, String(s))
-end
-
-function Base.parse(::Type{<:Edit{Se, Sy}}, s::Union{String, SubString{String}}) where {Se, Sy}
-    # Either "Δ1-2", "11T" or "G16C"
-    if (m = match(r"^Δ(\d+)-(\d+)$", s); m) !== nothing
-        pos = parse(UInt, m[1])
-        stop = parse(UInt, m[2])
-        stop ≥ pos || throw(ArgumentError("Non-positive deletion length: \"" * s * "\""))
-        Edit{Se, Sy}(Deletion(stop - pos + 1), pos)
-    elseif (m = match(r"^(\d+)([A-Za-z]+)$", s); m) !== nothing
-        pos = parse(UInt, m[1])
-        seq = Se(m[2])
-        Edit{Se, Sy}(Insertion(seq), pos)
-    elseif (m = match(r"^[A-Za-z](\d+)([A-Za-z])$", s); m) !== nothing
-        pos = parse(UInt, m[1])
-        sym = Sy(first(m[2]))
-        Edit{Se, Sy}(Substitution(sym), pos)
-    else
-        throw(ArgumentError("Failed to parse edit \"" * s * '"'))
-    end
-end
-
-mutation(e::Edit) = e.x
-BioGenerics.leftposition(e::Edit) = e.pos
-function BioGenerics.rightposition(e::Edit)
-    if mutation(e) isa Substitution
-        return leftposition(e)
-    elseif mutation(e) isa Insertion
-        return leftposition(e) + 1
-    elseif mutation(e) isa Deletion
-        return leftposition(e) + length(e) - 1
-    else
-        error("Unknown mutation type $(typeof(mutation(e)))")
-    end
-end
+include("Edit.jl")
 
 # Edits are applied sequentially from first to last pos.
 # The vector must always be sorted by pos.
@@ -260,11 +160,6 @@ edits(v::Variant) = v.edits
 reference(v::Variant) = v.ref
 Base.:(==)(x::Variant, y::Variant) = x.ref == y.ref && x.edits == y.edits
 
-function lendiff(edit::Edit)
-    x = edit.x
-    x isa Substitution ? 0 : (x isa Deletion ? -length(x) : length(x.x))
-end
-
 function reconstruct!(seq::S, x::Variant{S}) where S
     len = length(x.ref) + sum(edit -> lendiff(edit), x.edits)
     resize!(seq, len % UInt)
@@ -422,42 +317,6 @@ function variations(v::Variant{S,T}) where {S,T}
     return vs
 end
 
-function _refbases(s::Substitution, reference::S, pos::UInt) where S <: BioSequence
-    return S([reference[pos]])
-end
-
-function _altbases(s::Substitution, reference::S, pos::UInt) where S <: BioSequence
-    return S([s.x])
-end
-
-function _refbases(d::Deletion, reference::S, pos::UInt) where S <: BioSequence
-    if pos == 1
-        return S(reference[UnitRange{Int}(pos, pos+length(d))])
-    else
-        return S(reference[UnitRange{Int}(pos-1, pos+length(d)-1)])
-    end
-end
-
-function _altbases(d::Deletion, reference::S, pos::UInt) where S <: BioSequence
-    if pos == 1
-        return S([reference[pos+1]])
-    else
-        return S([reference[pos-1]])
-    end
-end
-
-function _refbases(i::Insertion, reference::S, pos::UInt) where S <: BioSequence
-    return S([reference[pos]])
-end
-
-function _altbases(i::Insertion, reference::S, pos::UInt) where S <: BioSequence
-    if pos == 1
-        return S([i.seq..., reference[pos]])
-    else
-        return S([reference[pos], i.seq...])
-    end
-end
-
 function refbases(v::Variation)
     return _refbases(mutation(v), reference(v), leftposition(v))
 end