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# This file is a part of Julia. License is MIT: https://julialang.org/license
## file formats ##
module DataFmt
import Base: _default_delims, tryparse_internal, show
export countlines, readdlm, readcsv, writedlm, writecsv
invalid_dlm(::Type{Char}) = reinterpret(Char, 0xfffffffe)
invalid_dlm(::Type{UInt8}) = 0xfe
invalid_dlm(::Type{UInt16}) = 0xfffe
invalid_dlm(::Type{UInt32}) = 0xfffffffe
const offs_chunk_size = 5000
countlines(f::AbstractString, eol::Char='\n') = open(io->countlines(io,eol), f)::Int
"""
countlines(io::IO, eol::Char='\\n')
Read `io` until the end of the stream/file and count the number of lines. To specify a file
pass the filename as the first argument. EOL markers other than `'\\n'` are supported by
passing them as the second argument.
"""
function countlines(io::IO, eol::Char='\n')
isascii(eol) || throw(ArgumentError("only ASCII line terminators are supported"))
aeol = UInt8(eol)
a = Vector{UInt8}(8192)
nl = 0
while !eof(io)
nb = readbytes!(io, a)
@simd for i=1:nb
@inbounds nl += a[i] == aeol
end
end
nl
end
"""
readdlm(source, T::Type; options...)
The columns are assumed to be separated by one or more whitespaces. The end of line
delimiter is taken as `\\n`.
"""
readdlm(input, T::Type; opts...) = readdlm(input, invalid_dlm(Char), T, '\n'; opts...)
"""
readdlm(source, delim::Char, T::Type; options...)
The end of line delimiter is taken as `\\n`.
"""
readdlm(input, dlm::Char, T::Type; opts...) = readdlm(input, dlm, T, '\n'; opts...)
"""
readdlm(source; options...)
The columns are assumed to be separated by one or more whitespaces. The end of line
delimiter is taken as `\\n`. If all data is numeric, the result will be a numeric array. If
some elements cannot be parsed as numbers, a heterogeneous array of numbers and strings
is returned.
"""
readdlm(input; opts...) = readdlm(input, invalid_dlm(Char), '\n'; opts...)
"""
readdlm(source, delim::Char; options...)
The end of line delimiter is taken as `\\n`. If all data is numeric, the result will be a
numeric array. If some elements cannot be parsed as numbers, a heterogeneous array of
numbers and strings is returned.
"""
readdlm(input, dlm::Char; opts...) = readdlm(input, dlm, '\n'; opts...)
"""
readdlm(source, delim::Char, eol::Char; options...)
If all data is numeric, the result will be a numeric array. If some elements cannot be
parsed as numbers, a heterogeneous array of numbers and strings is returned.
"""
readdlm(input, dlm::Char, eol::Char; opts...) =
readdlm_auto(input, dlm, Float64, eol, true; opts...)
"""
readdlm(source, delim::Char, T::Type, eol::Char; header=false, skipstart=0, skipblanks=true, use_mmap, quotes=true, dims, comments=true, comment_char='#')
Read a matrix from the source where each line (separated by `eol`) gives one row, with
elements separated by the given delimiter. The source can be a text file, stream or byte
array. Memory mapped files can be used by passing the byte array representation of the
mapped segment as source.
If `T` is a numeric type, the result is an array of that type, with any non-numeric elements
as `NaN` for floating-point types, or zero. Other useful values of `T` include
`String`, `AbstractString`, and `Any`.
If `header` is `true`, the first row of data will be read as header and the tuple
`(data_cells, header_cells)` is returned instead of only `data_cells`.
Specifying `skipstart` will ignore the corresponding number of initial lines from the input.
If `skipblanks` is `true`, blank lines in the input will be ignored.
If `use_mmap` is `true`, the file specified by `source` is memory mapped for potential
speedups. Default is `true` except on Windows. On Windows, you may want to specify `true` if
the file is large, and is only read once and not written to.
If `quotes` is `true`, columns enclosed within double-quote (\") characters are allowed to
contain new lines and column delimiters. Double-quote characters within a quoted field must
be escaped with another double-quote. Specifying `dims` as a tuple of the expected rows and
columns (including header, if any) may speed up reading of large files. If `comments` is
`true`, lines beginning with `comment_char` and text following `comment_char` in any line
are ignored.
"""
readdlm(input, dlm::Char, T::Type, eol::Char; opts...) =
readdlm_auto(input, dlm, T, eol, false; opts...)
readdlm_auto(input::Vector{UInt8}, dlm::Char, T::Type, eol::Char, auto::Bool; opts...) =
readdlm_string(String(input), dlm, T, eol, auto, val_opts(opts))
readdlm_auto(input::IO, dlm::Char, T::Type, eol::Char, auto::Bool; opts...) =
readdlm_string(readstring(input), dlm, T, eol, auto, val_opts(opts))
function readdlm_auto(input::AbstractString, dlm::Char, T::Type, eol::Char, auto::Bool; opts...)
optsd = val_opts(opts)
use_mmap = get(optsd, :use_mmap, is_windows() ? false : true)
fsz = filesize(input)
if use_mmap && fsz > 0 && fsz < typemax(Int)
a = open(input, "r") do f
Mmap.mmap(f, Vector{UInt8}, (Int(fsz),))
end
# TODO: It would be nicer to use String(a) without making a copy,
# but because the mmap'ed array is not NUL-terminated this causes
# jl_try_substrtod to segfault below.
return readdlm_string(unsafe_string(pointer(a),length(a)), dlm, T, eol, auto, optsd)
else
return readdlm_string(readstring(input), dlm, T, eol, auto, optsd)
end
end
#
# Handlers act on events generated by the parser.
# Parser calls store_cell on the handler to pass events.
#
# DLMOffsets: Keep offsets (when result dimensions are not known)
# DLMStore: Store values directly into a result store (when result dimensions are known)
abstract type DLMHandler end
mutable struct DLMOffsets <: DLMHandler
oarr::Vector{Vector{Int}}
offidx::Int
thresh::Int
bufflen::Int
function DLMOffsets(sbuff::String)
offsets = Vector{Vector{Int}}(1)
offsets[1] = Vector{Int}(offs_chunk_size)
thresh = ceil(min(typemax(UInt), Base.Sys.total_memory()) / sizeof(Int) / 5)
new(offsets, 1, thresh, sizeof(sbuff))
end
end
function store_cell(dlmoffsets::DLMOffsets, row::Int, col::Int,
quoted::Bool, startpos::Int, endpos::Int)
offidx = dlmoffsets.offidx
(offidx == 0) && return # offset collection stopped to avoid choking on memory
oarr = dlmoffsets.oarr
offsets = oarr[end]
if length(offsets) < offidx
offlen = offs_chunk_size * length(oarr)
if (offlen + offs_chunk_size) > dlmoffsets.thresh
est_tot = round(Int, offlen * dlmoffsets.bufflen / endpos)
if (est_tot - offlen) > offs_chunk_size # allow another chunk
# abandon offset collection
dlmoffsets.oarr = Vector{Int}[]
dlmoffsets.offidx = 0
return
end
end
offsets = Vector{Int}(offs_chunk_size)
push!(oarr, offsets)
offidx = 1
end
offsets[offidx] = row
offsets[offidx+1] = col
offsets[offidx+2] = Int(quoted)
offsets[offidx+3] = startpos
offsets[offidx+4] = endpos
dlmoffsets.offidx = offidx + 5
nothing
end
function result(dlmoffsets::DLMOffsets)
trimsz = (dlmoffsets.offidx-1) % offs_chunk_size
((trimsz > 0) || (dlmoffsets.offidx == 1)) && resize!(dlmoffsets.oarr[end], trimsz)
dlmoffsets.oarr
end
mutable struct DLMStore{T} <: DLMHandler
hdr::Array{AbstractString, 2}
data::Array{T, 2}
nrows::Int
ncols::Int
lastrow::Int
lastcol::Int
hdr_offset::Int
sbuff::String
auto::Bool
eol::Char
end
function DLMStore(::Type{T}, dims::NTuple{2,Integer},
has_header::Bool, sbuff::String, auto::Bool, eol::Char) where T
(nrows,ncols) = dims
nrows <= 0 && throw(ArgumentError("number of rows in dims must be > 0, got $nrows"))
ncols <= 0 && throw(ArgumentError("number of columns in dims must be > 0, got $ncols"))
hdr_offset = has_header ? 1 : 0
DLMStore{T}(fill(SubString(sbuff,1,0), 1, ncols), Matrix{T}(nrows-hdr_offset, ncols),
nrows, ncols, 0, 0, hdr_offset, sbuff, auto, eol)
end
_chrinstr(sbuff::String, chr::UInt8, startpos::Int, endpos::Int) =
(endpos >= startpos) && (C_NULL != ccall(:memchr, Ptr{UInt8},
(Ptr{UInt8}, Int32, Csize_t), pointer(sbuff)+startpos-1, chr, endpos-startpos+1))
function store_cell(dlmstore::DLMStore{T}, row::Int, col::Int,
quoted::Bool, startpos::Int, endpos::Int) where T
drow = row - dlmstore.hdr_offset
ncols = dlmstore.ncols
lastcol = dlmstore.lastcol
lastrow = dlmstore.lastrow
cells::Matrix{T} = dlmstore.data
sbuff = dlmstore.sbuff
endpos = prevind(sbuff, nextind(sbuff,endpos))
if (endpos > 0) && ('\n' == dlmstore.eol) && ('\r' == Char(sbuff[endpos]))
endpos = prevind(sbuff, endpos)
end
if quoted
startpos += 1
endpos = prevind(sbuff, endpos)
end
if drow > 0
# fill missing elements
while ((drow - lastrow) > 1) || ((drow > lastrow > 0) && (lastcol < ncols))
if (lastcol == ncols) || (lastrow == 0)
lastcol = 0
lastrow += 1
end
for cidx in (lastcol+1):ncols
if (T <: AbstractString) || (T == Any)
cells[lastrow, cidx] = SubString(sbuff, 1, 0)
elseif ((T <: Number) || (T <: Char)) && dlmstore.auto
throw(TypeError(:store_cell, "", Any, T))
else
error("missing value at row $lastrow column $cidx")
end
end
lastcol = ncols
end
# fill data
if quoted && _chrinstr(sbuff, UInt8('"'), startpos, endpos)
unescaped = replace(SubString(sbuff, startpos, endpos), r"\"\"", "\"")
fail = colval(unescaped, 1, endof(unescaped), cells, drow, col)
else
fail = colval(sbuff, startpos, endpos, cells, drow, col)
end
if fail
sval = SubString(sbuff, startpos, endpos)
if (T <: Number) && dlmstore.auto
throw(TypeError(:store_cell, "", Any, T))
else
error("file entry \"$(sval)\" cannot be converted to $T")
end
end
dlmstore.lastrow = drow
dlmstore.lastcol = col
else
# fill header
if quoted && _chrinstr(sbuff, UInt8('"'), startpos, endpos)
unescaped = replace(SubString(sbuff, startpos, endpos), r"\"\"", "\"")
colval(unescaped, 1, endof(unescaped), dlmstore.hdr, 1, col)
else
colval(sbuff, startpos, endpos, dlmstore.hdr, 1, col)
end
end
nothing
end
function result(dlmstore::DLMStore{T}) where T
nrows = dlmstore.nrows - dlmstore.hdr_offset
ncols = dlmstore.ncols
lastcol = dlmstore.lastcol
lastrow = dlmstore.lastrow
cells = dlmstore.data
sbuff = dlmstore.sbuff
if (nrows > 0) && ((lastcol < ncols) || (lastrow < nrows))
while lastrow <= nrows
(lastcol == ncols) && (lastcol = 0; lastrow += 1)
for cidx in (lastcol+1):ncols
if (T <: AbstractString) || (T == Any)
cells[lastrow, cidx] = SubString(sbuff, 1, 0)
elseif ((T <: Number) || (T <: Char)) && dlmstore.auto
throw(TypeError(:store_cell, "", Any, T))
else
error("missing value at row $lastrow column $cidx")
end
end
lastcol = ncols
(lastrow == nrows) && break
end
dlmstore.lastrow = lastrow
dlmstore.lastcol = ncols
end
(dlmstore.hdr_offset > 0) ? (dlmstore.data, dlmstore.hdr) : dlmstore.data
end
function readdlm_string(sbuff::String, dlm::Char, T::Type, eol::Char, auto::Bool, optsd::Dict)
ign_empty = (dlm == invalid_dlm(Char))
quotes = get(optsd, :quotes, true)
comments = get(optsd, :comments, true)
comment_char = get(optsd, :comment_char, '#')
dims = get(optsd, :dims, nothing)
has_header = get(optsd, :header, get(optsd, :has_header, false))
haskey(optsd, :has_header) && (optsd[:has_header] != has_header) && throw(ArgumentError("conflicting values for header and has_header"))
skipstart = get(optsd, :skipstart, 0)
(skipstart >= 0) || throw(ArgumentError("skipstart must be ≥ 0, got $skipstart"))
skipblanks = get(optsd, :skipblanks, true)
offset_handler = (dims === nothing) ? DLMOffsets(sbuff) : DLMStore(T, dims, has_header, sbuff, auto, eol)
for retry in 1:2
try
dims = dlm_parse(sbuff, eol, dlm, '"', comment_char, ign_empty, quotes, comments, skipstart, skipblanks, offset_handler)
break
catch ex
if isa(ex, TypeError) && (ex.func == :store_cell)
T = ex.expected
else
rethrow(ex)
end
offset_handler = (dims === nothing) ? DLMOffsets(sbuff) : DLMStore(T, dims, has_header, sbuff, auto, eol)
end
end
isa(offset_handler, DLMStore) && (return result(offset_handler))
offsets = result(offset_handler)
!isempty(offsets) && (return dlm_fill(T, offsets, dims, has_header, sbuff, auto, eol))
optsd[:dims] = dims
return readdlm_string(sbuff, dlm, T, eol, auto, optsd)
end
const valid_opts = [:header, :has_header, :use_mmap, :quotes, :comments, :dims, :comment_char, :skipstart, :skipblanks]
const valid_opt_types = [Bool, Bool, Bool, Bool, Bool, NTuple{2,Integer}, Char, Integer, Bool]
function val_opts(opts)
d = Dict{Symbol,Union{Bool,NTuple{2,Integer},Char,Integer}}()
for (opt_name, opt_val) in opts
in(opt_name, valid_opts) ||
throw(ArgumentError("unknown option $opt_name"))
opt_typ = valid_opt_types[findfirst(valid_opts, opt_name)]
isa(opt_val, opt_typ) ||
throw(ArgumentError("$opt_name should be of type $opt_typ, got $(typeof(opt_val))"))
d[opt_name] = opt_val
end
return d
end
function dlm_fill(T::DataType, offarr::Vector{Vector{Int}}, dims::NTuple{2,Integer}, has_header::Bool, sbuff::String, auto::Bool, eol::Char)
idx = 1
offidx = 1
offsets = offarr[1]
row = 0
col = 0
try
dh = DLMStore(T, dims, has_header, sbuff, auto, eol)
while idx <= length(offsets)
row = offsets[idx]
col = offsets[idx+1]
quoted = offsets[idx+2] != 0
startpos = offsets[idx+3]
endpos = offsets[idx+4]
((idx += 5) > offs_chunk_size) && (offidx < length(offarr)) && (idx = 1; offsets = offarr[offidx += 1])
store_cell(dh, row, col, quoted, startpos, endpos)
end
return result(dh)
catch ex
isa(ex, TypeError) && (ex.func == :store_cell) && (return dlm_fill(ex.expected, offarr, dims, has_header, sbuff, auto, eol))
error("at row $row, column $col : $ex")
end
end
function colval(sbuff::String, startpos::Int, endpos::Int, cells::Array{Bool,2}, row::Int, col::Int)
n = tryparse_internal(Bool, sbuff, startpos, endpos, 0, false)
isnull(n) || (cells[row, col] = get(n))
isnull(n)
end
function colval(sbuff::String, startpos::Int, endpos::Int, cells::Array{T,2}, row::Int, col::Int) where T<:Integer
n = tryparse_internal(T, sbuff, startpos, endpos, 0, false)
isnull(n) || (cells[row, col] = get(n))
isnull(n)
end
function colval(sbuff::String, startpos::Int, endpos::Int, cells::Array{Float64,2}, row::Int, col::Int)
n = ccall(:jl_try_substrtod, Nullable{Float64}, (Ptr{UInt8},Csize_t,Csize_t), sbuff, startpos-1, endpos-startpos+1)
isnull(n) || (cells[row, col] = get(n))
isnull(n)
end
function colval(sbuff::String, startpos::Int, endpos::Int, cells::Array{Float32,2}, row::Int, col::Int)
n = ccall(:jl_try_substrtof, Nullable{Float32}, (Ptr{UInt8}, Csize_t, Csize_t), sbuff, startpos-1, endpos-startpos+1)
isnull(n) || (cells[row, col] = get(n))
isnull(n)
end
function colval(sbuff::String, startpos::Int, endpos::Int, cells::Array{<:AbstractString,2}, row::Int, col::Int)
cells[row, col] = SubString(sbuff, startpos, endpos)
return false
end
function colval(sbuff::String, startpos::Int, endpos::Int, cells::Array{Any,2}, row::Int, col::Int)
# if array is of Any type, attempt parsing only the most common types: Int, Bool, Float64 and fallback to SubString
len = endpos-startpos+1
if len > 0
# check Inteter
ni64 = tryparse_internal(Int, sbuff, startpos, endpos, 0, false)
isnull(ni64) || (cells[row, col] = get(ni64); return false)
# check Bool
nb = tryparse_internal(Bool, sbuff, startpos, endpos, 0, false)
isnull(nb) || (cells[row, col] = get(nb); return false)
# check float64
nf64 = ccall(:jl_try_substrtod, Nullable{Float64}, (Ptr{UInt8}, Csize_t, Csize_t), sbuff, startpos-1, endpos-startpos+1)
isnull(nf64) || (cells[row, col] = get(nf64); return false)
end
cells[row, col] = SubString(sbuff, startpos, endpos)
false
end
function colval(sbuff::String, startpos::Int, endpos::Int, cells::Array{<:Char,2}, row::Int, col::Int)
if startpos == endpos
cells[row, col] = next(sbuff, startpos)[1]
return false
else
return true
end
end
colval(sbuff::String, startpos::Int, endpos::Int, cells::Array, row::Int, col::Int) = true
function dlm_parse(dbuff::String, eol::D, dlm::D, qchar::D, cchar::D,
ign_adj_dlm::Bool, allow_quote::Bool, allow_comments::Bool,
skipstart::Int, skipblanks::Bool, dh::DLMHandler) where D
ncols = nrows = col = 0
is_default_dlm = (dlm == invalid_dlm(D))
error_str = ""
# 0: begin field, 1: quoted field, 2: unquoted field,
# 3: second quote (could either be end of field or escape character),
# 4: comment, 5: skipstart
state = (skipstart > 0) ? 5 : 0
is_eol = is_dlm = is_cr = is_quote = is_comment = expct_col = false
idx = 1
try
slen = sizeof(dbuff)
col_start_idx = 1
was_cr = false
while idx <= slen
val,idx = next(dbuff, idx)
if (is_eol = (Char(val) == Char(eol)))
is_dlm = is_comment = is_cr = is_quote = false
elseif (is_dlm = (is_default_dlm ? in(Char(val), _default_delims) : (Char(val) == Char(dlm))))
is_comment = is_cr = is_quote = false
elseif (is_quote = (Char(val) == Char(qchar)))
is_comment = is_cr = false
elseif (is_comment = (Char(val) == Char(cchar)))
is_cr = false
else
is_cr = (Char(eol) == '\n') && (Char(val) == '\r')
end
if 2 == state # unquoted field
if is_dlm
state = 0
col += 1
store_cell(dh, nrows+1, col, false, col_start_idx, idx-2)
col_start_idx = idx
!ign_adj_dlm && (expct_col = true)
elseif is_eol
nrows += 1
col += 1
store_cell(dh, nrows, col, false, col_start_idx, idx - (was_cr ? 3 : 2))
col_start_idx = idx
ncols = max(ncols, col)
col = 0
state = 0
elseif (is_comment && allow_comments)
nrows += 1
col += 1
store_cell(dh, nrows, col, false, col_start_idx, idx - 2)
ncols = max(ncols, col)
col = 0
state = 4
end
elseif 1 == state # quoted field
is_quote && (state = 3)
elseif 4 == state # comment line
if is_eol
col_start_idx = idx
state = 0
end
elseif 0 == state # begin field
if is_quote
state = (allow_quote && !was_cr) ? 1 : 2
expct_col = false
elseif is_dlm
if !ign_adj_dlm
expct_col = true
col += 1
store_cell(dh, nrows+1, col, false, col_start_idx, idx-2)
end
col_start_idx = idx
elseif is_eol
if (col > 0) || !skipblanks
nrows += 1
if expct_col
col += 1
store_cell(dh, nrows, col, false, col_start_idx, idx - (was_cr ? 3 : 2))
end
ncols = max(ncols, col)
col = 0
end
col_start_idx = idx
expct_col = false
elseif is_comment && allow_comments
if col > 0
nrows += 1
if expct_col
col += 1
store_cell(dh, nrows, col, false, col_start_idx, idx - 2)
end
ncols = max(ncols, col)
col = 0
end
expct_col = false
state = 4
elseif !is_cr
state = 2
expct_col = false
end
elseif 3 == state # second quote
if is_quote && !was_cr
state = 1
elseif is_dlm && !was_cr
state = 0
col += 1
store_cell(dh, nrows+1, col, true, col_start_idx, idx-2)
col_start_idx = idx
!ign_adj_dlm && (expct_col = true)
elseif is_eol
nrows += 1
col += 1
store_cell(dh, nrows, col, true, col_start_idx, idx - (was_cr ? 3 : 2))
col_start_idx = idx
ncols = max(ncols, col)
col = 0
state = 0
elseif is_comment && allow_comments && !was_cr
nrows += 1
col += 1
store_cell(dh, nrows, col, true, col_start_idx, idx - 2)
ncols = max(ncols, col)
col = 0
state = 4
elseif (is_cr && was_cr) || !is_cr
error_str = escape_string("unexpected character '$(Char(val))' after quoted field at row $(nrows+1) column $(col+1)")
break
end
elseif 5 == state # skip start
if is_eol
col_start_idx = idx
skipstart -= 1
(0 == skipstart) && (state = 0)
end
end
was_cr = is_cr
end
if isempty(error_str)
if 1 == state # quoted field
error_str = "truncated column at row $(nrows+1) column $(col+1)"
elseif (2 == state) || (3 == state) || ((0 == state) && is_dlm) # unquoted field, second quote, or begin field with last character as delimiter
col += 1
nrows += 1
store_cell(dh, nrows, col, (3 == state), col_start_idx, idx-1)
ncols = max(ncols, col)
end
end
catch ex
if isa(ex, TypeError) && (ex.func == :store_cell)
rethrow(ex)
else
error("at row $(nrows+1), column $col : $ex)")
end
end
!isempty(error_str) && error(error_str)
return (nrows, ncols)
end
readcsv(io; opts...) = readdlm(io, ','; opts...)
readcsv(io, T::Type; opts...) = readdlm(io, ',', T; opts...)
# todo: keyword argument for # of digits to print
writedlm_cell(io::IO, elt::AbstractFloat, dlm, quotes) = print_shortest(io, elt)
function writedlm_cell(io::IO, elt::AbstractString, dlm::T, quotes::Bool) where T
if quotes && !isempty(elt) && (('"' in elt) || ('\n' in elt) || ((T <: Char) ? (dlm in elt) : contains(elt, dlm)))
print(io, '"', replace(elt, r"\"", "\"\""), '"')
else
print(io, elt)
end
end
writedlm_cell(io::IO, elt, dlm, quotes) = print(io, elt)
function writedlm(io::IO, a::AbstractMatrix, dlm; opts...)
optsd = val_opts(opts)
quotes = get(optsd, :quotes, true)
pb = PipeBuffer()
lastc = last(indices(a, 2))
for i = indices(a, 1)
for j = indices(a, 2)
writedlm_cell(pb, a[i, j], dlm, quotes)
j == lastc ? write(pb,'\n') : print(pb,dlm)
end
(nb_available(pb) > (16*1024)) && write(io, take!(pb))
end
write(io, take!(pb))
nothing
end
writedlm(io::IO, a::AbstractArray{<:Any,0}, dlm; opts...) = writedlm(io, reshape(a,1), dlm; opts...)
# write an iterable row as dlm-separated items
function writedlm_row(io::IO, row, dlm, quotes)
state = start(row)
while !done(row, state)
(x, state) = next(row, state)
writedlm_cell(io, x, dlm, quotes)
done(row, state) ? write(io,'\n') : print(io,dlm)
end
end
# If the row is a single string, write it as a string rather than
# iterating over characters. Also, include the common case of
# a Number (handled correctly by the generic writedlm_row above)
# purely as an optimization.
function writedlm_row(io::IO, row::Union{Number,AbstractString}, dlm, quotes)
writedlm_cell(io, row, dlm, quotes)
write(io, '\n')
end
# write an iterable collection of iterable rows
function writedlm(io::IO, itr, dlm; opts...)
optsd = val_opts(opts)
quotes = get(optsd, :quotes, true)
pb = PipeBuffer()
for row in itr
writedlm_row(pb, row, dlm, quotes)
(nb_available(pb) > (16*1024)) && write(io, take!(pb))
end
write(io, take!(pb))
nothing
end
function writedlm(fname::AbstractString, a, dlm; opts...)
open(fname, "w") do io
writedlm(io, a, dlm; opts...)
end
end
"""
writedlm(f, A, delim='\\t'; opts)
Write `A` (a vector, matrix, or an iterable collection of iterable rows) as text to `f`
(either a filename string or an `IO` stream) using the given delimiter
`delim` (which defaults to tab, but can be any printable Julia object, typically a `Char` or
`AbstractString`).
For example, two vectors `x` and `y` of the same length can be written as two columns of
tab-delimited text to `f` by either `writedlm(f, [x y])` or by `writedlm(f, zip(x, y))`.
"""
writedlm(io, a; opts...) = writedlm(io, a, '\t'; opts...)
"""
writecsv(filename, A; opts)
Equivalent to [`writedlm`](@ref) with `delim` set to comma.
"""
writecsv(io, a; opts...) = writedlm(io, a, ','; opts...)
show(io::IO, ::MIME"text/csv", a) = writedlm(io, a, ',')
show(io::IO, ::MIME"text/tab-separated-values", a) = writedlm(io, a, '\t')
end # module DataFmt