change skipchars(io, predicate) to skipchars(predicate, io)

This is to be consistent with our style guide.

NEWS.md

@@ -692,6 +692,9 @@ Deprecated or removed
 
  * `nb_available` is now `bytesavailable` ([#25634]).
 
+ * `skipchars(io::IO, predicate; linecomment=nothing)` is deprecated in favor of
+ `skipchars(predicate, io::IO; linecomment=nothing)` ([#25667]).
+
  * `Bidiagonal` constructors now use a `Symbol` (`:U` or `:L`) for the upper/lower
  argument, instead of a `Bool` or a `Char` ([#22703]).
 

base/deprecated.jl

@@ -1592,6 +1592,10 @@ end
 
 @deprecate nb_available bytesavailable
 
+@deprecate skipchars(io::IO, predicate; linecomment=nothing) skipchars(predicate, io, linecomment=linecomment)
+# this method is to avoid ambiguity, delete at the same time as deprecation of skipchars above:
+skipchars(::IO, ::IO; linecomment=nothing) = throw(ArgumentError("the first argument of `skipchars` must be callable"))
+
 # issue #9053
 if Sys.iswindows()
 function Filesystem.tempname(uunique::UInt32)

base/io.jl

@@ -912,7 +912,7 @@ Commit all currently buffered writes to the given stream.
 flush(io::IO) = nothing
 
 """
- skipchars(io::IO, predicate; linecomment=nothing)
+ skipchars(predicate, io::IO; linecomment=nothing)
 
 Advance the stream `io` such that the next-read character will be the first remaining for
 which `predicate` returns `false`. If the keyword argument `linecomment` is specified, all
@@ -923,19 +923,19 @@ characters from that character until the start of the next line are ignored.
 julia> buf = IOBuffer(" text")
 IOBuffer(data=UInt8[...], readable=true, writable=false, seekable=true, append=false, size=8, maxsize=Inf, ptr=1, mark=-1)
 
-julia> skipchars(buf, isspace)
+julia> skipchars(isspace, buf)
 IOBuffer(data=UInt8[...], readable=true, writable=false, seekable=true, append=false, size=8, maxsize=Inf, ptr=5, mark=-1)
 
 julia> String(readavailable(buf))
 "text"
 ```
 """
-function skipchars(io::IO, pred; linecomment=nothing)
+function skipchars(predicate, io::IO; linecomment=nothing)
  while !eof(io)
  c = read(io, Char)
  if c === linecomment
  readline(io)
- elseif !pred(c)
+ elseif !predicate(c)
  skip(io, -codelen(c))
  break
  end

base/repl/LineEdit.jl

@@ -1037,7 +1037,7 @@ end
 
 function edit_replace_word_right(buf::IOBuffer, replace::Function)
  # put the cursor at the beginning of the next word
- skipchars(buf, is_non_word_char)
+ skipchars(is_non_word_char, buf)
  b = position(buf)
  char_move_word_right(buf)
  e = position(buf)

test/iobuffer.jl

@@ -262,25 +262,25 @@ end
 # skipchars
 let
  io = IOBuffer("")
- @test eof(skipchars(io, isspace))
+ @test eof(skipchars(isspace, io))
 
  io = IOBuffer(" ")
- @test eof(skipchars(io, isspace))
+ @test eof(skipchars(isspace, io))
 
  io = IOBuffer("# \n ")
- @test eof(skipchars(io, isspace, linecomment='#'))
+ @test eof(skipchars(isspace, io, linecomment='#'))
 
  io = IOBuffer(" text")
- skipchars(io, isspace)
+ skipchars(isspace, io)
  @test String(readavailable(io)) == "text"
 
  io = IOBuffer(" # comment \n text")
- skipchars(io, isspace, linecomment='#')
+ skipchars(isspace, io, linecomment='#')
  @test String(readavailable(io)) == "text"
 
  for char in ['@','߷','࿊','𐋺']
  io = IOBuffer("alphabeticalstuff$char")
- @test !eof(skipchars(io, isalpha))
+ @test !eof(skipchars(isalpha, io))
  @test read(io, Char) == char
  end
 end

test/iostream.jl

@@ -10,31 +10,31 @@ mktemp() do path, file
  end
 
  # test it doesn't error on eof
- @test eof(skipchars(file, isspace))
+ @test eof(skipchars(isspace, file))
 
  # test it correctly skips
  append_to_file(" ")
- @test eof(skipchars(file, isspace))
+ @test eof(skipchars(isspace, file))
 
  # test it correctly detects comment lines
  append_to_file("# \n ")
- @test eof(skipchars(file, isspace, linecomment='#'))
+ @test eof(skipchars(isspace, file, linecomment='#'))
 
  # test it stops at the appropriate time
  append_to_file(" not a space")
- @test !eof(skipchars(file, isspace))
+ @test !eof(skipchars(isspace, file))
  @test read(file, Char) == 'n'
 
  # test it correctly ignores the contents of comment lines
  append_to_file(" #not a space \n not a space")
- @test !eof(skipchars(file, isspace, linecomment='#'))
+ @test !eof(skipchars(isspace, file, linecomment='#'))
  @test read(file, Char) == 'n'
 
  # test it correctly handles unicode
  for (byte,char) in zip(1:4, ('@','߷','࿊','𐋺'))
  append_to_file("abcdef$char")
  @test Base.codelen(char) == byte
- @test !eof(skipchars(file, isalpha))
+ @test !eof(skipchars(isalpha, file))
  @test read(file, Char) == char
  end
 end