add keyword arguments to IOBuffer's constructors

base/deprecated.jl

@@ -1415,6 +1415,11 @@ end
 
 @deprecate which(s::Symbol) which(Main, s)
 
+@deprecate IOBuffer(data::AbstractVector{UInt8}, read::Bool, write::Bool=false, maxsize::Integer=typemax(Int)) IOBuffer(data, read=read, write=write, maxsize=maxsize)
+@deprecate IOBuffer(read::Bool, write::Bool) IOBuffer(read=read, write=write)
+@deprecate IOBuffer(maxsize::Integer) IOBuffer(read=true, write=true, maxsize=maxsize)
+
+
 # END 0.7 deprecations
 
 # BEGIN 1.0 deprecations

base/int.jl

@@ -539,7 +539,7 @@ end
 macro big_str(s)
     if '_' in s
         # remove _ in s[2:end-1]
-        bf = IOBuffer(lastindex(s))
+        bf = IOBuffer(maxsize=lastindex(s))
         print(bf, s[1])
         for c in SubString(s, 2, lastindex(s)-1)
             c != '_' && print(bf, c)

base/iobuffer.jl

@@ -32,15 +32,27 @@ StringVector(n::Integer) = unsafe_wrap(Vector{UInt8}, _string_n(n))
 # IOBuffers behave like Files. They are typically readable and writable. They are seekable. (They can be appendable).
 
 """
-    IOBuffer([data, ][readable::Bool=true, writable::Bool=false[, maxsize::Int=typemax(Int)]])
+    IOBuffer([data::AbstractVector{UInt8}]; keywords...) -> IOBuffer
 
-Create an `IOBuffer`, which may optionally operate on a pre-existing array. If the
-readable/writable arguments are given, they restrict whether or not the buffer may be read
-from or written to respectively. The last argument optionally specifies a size beyond which
-the buffer may not be grown.
+Create an in-memory I/O stream, which may optionally operate on a pre-existing array.
+
+It may take optional keyword arguments:
+- `read`, `write`, `append`: restricts operations to the buffer; see `open` for details.
+- `truncate`: truncates the buffer size to zero length.
+- `maxsize`: specifies a size beyond which the buffer may not be grown.
+
+When `data` is not given, the buffer will be both readable and writable by default.
 
 # Examples
 ```jldoctest
+julia> io = IOBuffer();
+
+julia> write(io, "JuliaLang is a GitHub organization.", " It has many members.")
+56
+
+julia> String(take!(io))
+"JuliaLang is a GitHub organization. It has many members."
+
 julia> io = IOBuffer("JuliaLang is a GitHub organization.")
 IOBuffer(data=UInt8[...], readable=true, writable=false, seekable=true, append=false, size=35, maxsize=Inf, ptr=1, mark=-1)
 
@@ -50,7 +62,7 @@ julia> read(io, String)
 julia> write(io, "This isn't writable.")
 ERROR: ArgumentError: ensureroom failed, IOBuffer is not writeable
 
-julia> io = IOBuffer(UInt8[], true, true, 34)
+julia> io = IOBuffer(UInt8[], read=true, write=true, maxsize=34)
 IOBuffer(data=UInt8[...], readable=true, writable=true, seekable=true, append=false, size=0, maxsize=34, ptr=1, mark=-1)
 
 julia> write(io, "JuliaLang is a GitHub organization.")
@@ -60,57 +72,45 @@ julia> String(take!(io))
 "JuliaLang is a GitHub organization"
 ```
 """
-IOBuffer(data::AbstractVector{UInt8}, readable::Bool=true, writable::Bool=false, maxsize::Integer=typemax(Int)) =
-    GenericIOBuffer(data, readable, writable, true, false, maxsize)
-function IOBuffer(readable::Bool, writable::Bool)
-    b = IOBuffer(StringVector(32), readable, writable)
-    b.data[:] = 0
-    b.size = 0
-    return b
+function IOBuffer(
+        data::AbstractVector{UInt8};
+        read::Union{Bool,Nothing}=nothing,
+        write::Union{Bool,Nothing}=nothing,
+        append::Union{Bool,Nothing}=nothing,
+        truncate::Union{Bool,Nothing}=nothing,
+        maxsize::Integer=typemax(Int))
+    if maxsize < 0
+        throw(ArgumentError("negative maxsize: $(maxsize)"))
+    end
+    flags = open_flags(read=read, write=write, append=append, truncate=truncate)
+    buf = GenericIOBuffer(data, flags.read, flags.write, true, flags.append, Int(maxsize))
+    if flags.truncate
+        buf.size = 0
+    end
+    return buf
 end
 
-"""
-    IOBuffer() -> IOBuffer
-
-Create an in-memory I/O stream, which is both readable and writable.
-
-# Examples
-```jldoctest
-julia> io = IOBuffer();
-
-julia> write(io, "JuliaLang is a GitHub organization.", " It has many members.")
-56
-
-julia> String(take!(io))
-"JuliaLang is a GitHub organization. It has many members."
-```
-"""
-IOBuffer() = IOBuffer(true, true)
-
-"""
-    IOBuffer(size::Integer)
-
-Create a fixed size IOBuffer. The buffer will not grow dynamically.
-
-# Examples
-```jldoctest
-julia> io = IOBuffer(12)
-IOBuffer(data=UInt8[...], readable=true, writable=true, seekable=true, append=false, size=0, maxsize=12, ptr=1, mark=-1)
-
-julia> write(io, "Hello world.")
-12
-
-julia> String(take!(io))
-"Hello world."
-
-julia> write(io, "Hello world again.")
-12
-
-julia> String(take!(io))
-"Hello world "
-```
-"""
-IOBuffer(maxsize::Integer) = (x=IOBuffer(StringVector(maxsize), true, true, maxsize); x.size=0; x)
+function IOBuffer(;
+        read::Union{Bool,Nothing}=true,
+        write::Union{Bool,Nothing}=true,
+        append::Union{Bool,Nothing}=nothing,
+        truncate::Union{Bool,Nothing}=true,
+        maxsize::Integer=typemax(Int))
+    size = maxsize == typemax(Int) ? 32 : Int(maxsize)
+    flags = open_flags(read=read, write=write, append=append, truncate=truncate)
+    buf = IOBuffer(
+        StringVector(size),
+        read=flags.read,
+        write=flags.write,
+        append=flags.append,
+        truncate=flags.truncate,
+        maxsize=maxsize)
+    buf.data[:] = 0
+    if flags.truncate
+        buf.size = 0
+    end
+    return buf
+end
 
 # PipeBuffers behave like Unix Pipes. They are typically readable and writable, they act appendable, and are not seekable.
 

base/printf.jl

@@ -1114,7 +1114,7 @@ function bigfloat_printf(out, d::BigFloat, flags::String, width::Int, precision:
     if precision >= 0
         fmt_len += ndigits(precision)+1
     end
-    fmt = IOBuffer(fmt_len)
+    fmt = IOBuffer(maxsize=fmt_len)
     write(fmt, '%')
     write(fmt, flags)
     if width > 0

base/strings/basic.jl

@@ -512,7 +512,7 @@ isascii(s::AbstractString) = all(isascii, s)
 ## string map, filter, has ##
 
 function map(f, s::AbstractString)
-    out = IOBuffer(StringVector(sizeof(s)), true, true)
+    out = IOBuffer(StringVector(sizeof(s)), read=true, write=true)
     truncate(out, 0)
     for c in s
         c′ = f(c)
@@ -525,7 +525,7 @@ function map(f, s::AbstractString)
 end
 
 function filter(f, s::AbstractString)
-    out = IOBuffer(StringVector(sizeof(s)), true, true)
+    out = IOBuffer(StringVector(sizeof(s)), read=true, write=true)
     truncate(out, 0)
     for c in s
         f(c) && write(out, c)

base/strings/io.jl

@@ -81,7 +81,7 @@ julia> sprint(showcompact, 66.66666)
 ```
 """
 function sprint(f::Function, args...; context=nothing, sizehint::Integer=0)
-    s = IOBuffer(StringVector(sizehint), true, true)
+    s = IOBuffer(StringVector(sizehint), read=true, write=true)
     # specialized version of truncate(s,0)
     s.size = 0
     s.ptr = 1
@@ -100,7 +100,7 @@ tostr_sizehint(x::Float32) = 12
 
 function print_to_string(xs...; env=nothing)
     # specialized for performance reasons
-    s = IOBuffer(StringVector(tostr_sizehint(xs[1])), true, true)
+    s = IOBuffer(StringVector(tostr_sizehint(xs[1])), read=true, write=true)
     # specialized version of truncate(s,0)
     s.size = 0
     s.ptr = 1
@@ -436,7 +436,7 @@ Returns:
 function unindent(str::AbstractString, indent::Int; tabwidth=8)
     indent == 0 && return str
     # Note: this loses the type of the original string
-    buf = IOBuffer(StringVector(sizeof(str)), true, true)
+    buf = IOBuffer(StringVector(sizeof(str)), read=true, write=true)
     truncate(buf,0)
     cutting = true
     col = 0     # current column (0 based)

base/strings/util.jl

@@ -383,7 +383,7 @@ function replace(str::String, pat_repl::Pair; count::Integer=typemax(Int))
     i = a = firstindex(str)
     r = coalesce(findnext(pattern,str,i), 0)
     j, k = first(r), last(r)
-    out = IOBuffer(StringVector(floor(Int, 1.2sizeof(str))), true, true)
+    out = IOBuffer(StringVector(floor(Int, 1.2sizeof(str))), read=true, write=true)
     out.size = 0
     out.ptr = 1
     while j != 0

stdlib/Dates/src/io.jl

@@ -481,7 +481,7 @@ end
 
 function format(dt::TimeType, fmt::DateFormat, bufsize=12)
     # preallocate to reduce resizing
-    io = IOBuffer(Vector{UInt8}(uninitialized, bufsize), true, true)
+    io = IOBuffer(Vector{UInt8}(uninitialized, bufsize), read=true, write=true)
     format(io, dt, fmt)
     String(io.data[1:io.ptr - 1])
 end

test/functional.jl

@@ -14,7 +14,7 @@ end
 @test isequal(map(sqrt, 2:6), [sqrt(i) for i in 2:6])
 
 # map on ranges should evaluate first value only once (#4453)
-let io=IOBuffer(3)
+let io=IOBuffer(maxsize=3)
     map(x->print(io,x), 1:2)
     @test String(take!(io))=="12"
 end
@@ -176,4 +176,4 @@ end
     @test res isa Vector{Union{Bool, T}}
     res = map(f, y)
     @test res isa Vector{Union{Bool, T}}
-end
+end

test/iobuffer.jl

@@ -195,7 +195,7 @@ end
 
 @testset "pr #11554" begin
     io  = IOBuffer(SubString("***αhelloworldω***", 4, 16))
-    io2 = IOBuffer(Vector{UInt8}(b"goodnightmoon"), true, true)
+    io2 = IOBuffer(Vector{UInt8}(b"goodnightmoon"), read=true, write=true)
 
     @test read(io, Char) == 'α'
     @test_throws ArgumentError write(io,"!")
@@ -227,7 +227,7 @@ end
 
 # issue #11917
 # (previous tests triggered this sometimes, but this should trigger nearly all the time)
-let io = IOBuffer(0)
+let io = IOBuffer(maxsize=0)
    write(io, fill(0x01, 1048577))
 end
 
@@ -289,11 +289,11 @@ end
 end
 
 @testset "Test constructor with a generic type argument." begin
-    io = IOBuffer(Int16(10))
+    io = IOBuffer(maxsize=Int16(10))
     @test io isa IOBuffer
-    io = IOBuffer(Int32(10))
+    io = IOBuffer(maxsize=Int32(10))
     @test io isa IOBuffer
-    io = IOBuffer(Int64(10))
+    io = IOBuffer(maxsize=Int64(10))
     @test io isa IOBuffer
 end
 

test/read.jl

@@ -343,7 +343,7 @@ for (name, f) in l
     @test read("$filename.to", String) == text
 
     verbose && println("$name write(::IOBuffer, ...)")
-    to = IOBuffer(Vector{UInt8}(codeunits(text)), false, true)
+    to = IOBuffer(Vector{UInt8}(codeunits(text)), read=false, write=true)
     write(to, io())
     @test String(take!(to)) == text
 

test/show.jl

@@ -755,7 +755,7 @@ end
 
 # PR 17117
 # test print_array
-let s = IOBuffer(Vector{UInt8}(), true, true)
+let s = IOBuffer(Vector{UInt8}(), read=true, write=true)
     Base.print_array(s, [1, 2, 3])
     @test String(resize!(s.data, s.size)) == " 1\n 2\n 3"
 end