This Julia package implements a new type of AbstractString
, a StringView
,
that provides a string representation of any underlying array of bytes
(any AbstractVector{UInt8}
), interpreted as UTF-8 encoded Unicode data.
Unlike Julia's built-in String
type (which also wraps UTF-8 data), the
StringView
type is a copy-free wrap of any AbstractVector{UInt8}
instance, and does not take "ownership" of or modify the array.
You can also use StringView(buf)
with a buf::IOBuffer
, as
a non-destructive alternative to String(take!(buf))
. Otherwise,
a StringView
is intended to be usable in any context where you might
have otherwise used String
.
(In particular, as much as possible we try to implement efficient copy-free
String
-like operations on StringView
, such as iteration and regular-expression
searching, as long as the underlying UInt8
array is a contiguous dense array.)
For example:
julia> b = [0x66, 0x6f, 0x6f, 0x62, 0x61, 0x72];
julia> s = StringView(b) # does not make a copy
"foobar"
julia> collect(eachmatch(r"[aeiou]+", s))
2-element Vector{SVRegexMatch{StringView{Vector{UInt8}}}}:
SVRegexMatch("oo")
SVRegexMatch("a")
julia> StringView(@view b[1:3]) # also works for subarrays, with no copy
"foo"
julia> abc = StringView(0x61:0x63) # and for other array types
"abc"
Or, with an IOBuffer
:
julia> buf = IOBuffer();
julia> write(buf, b);
julia> print(buf, "baz")
julia> StringView(buf) # does not modify buf
"foobarbaz"
julia> String(take!(buf)) # clears buf
"foobarbaz"
julia> StringView(buf) # now empty
""
Other optimized (copy-free) operations include I/O, hashing, iteration/indexing,
comparisons, parsing, searching, and validation. Working with a SubString
of
a StringView
is similarly efficient.