Rewrite shell_parse

base/shell.jl

@@ -28,42 +28,43 @@ function shell_parse(str::AbstractString, interpolate::Bool=true;
  in_single_quotes = false
  in_double_quotes = false
 
- args::Vector{Any} = []
- arg::Vector{Any} = []
+ args = []
+ arg = []
  i = firstindex(s)
  st = Iterators.Stateful(pairs(s))
 
- function update_arg(x)
+ function push_nonempty!(list, x)
  if !isa(x,AbstractString) || !isempty(x)
- push!(arg, x)
+ push!(list, x)
  end
+ return nothing
  end
- function consume_upto(s, i, j)
- update_arg(s[i:prevind(s, j)::Int])
- something(peek(st), (lastindex(s)::Int+1,'\0'))[1]
+ function consume_upto!(list, s, i, j)
+ push_nonempty!(list, s[i:prevind(s, j)::Int])
+ something(peek(st), lastindex(s)::Int+1 => '\0').first::Int
  end
- function append_arg()
- if isempty(arg); arg = Any["",]; end
- push!(args, arg)
- arg = []
+ function append_2to1!(list, innerlist)
+ if isempty(innerlist); push!(innerlist, ""); end
+ push!(list, copy(innerlist))
+ empty!(innerlist)
  end
 
  for (j, c) in st
- j::Int; c::AbstractChar
+ j, c = j::Int, c::eltype(str)
  if !in_single_quotes && !in_double_quotes && isspace(c)
- i = consume_upto(s, i, j)
- append_arg()
+ i = consume_upto!(arg, s, i, j)
+ append_2to1!(args, arg)
  while !isempty(st)
  # We've made sure above that we don't end in whitespace,
  # so updating `i` here is ok
- (i, c) = peek(st)
+ (i, c) = peek(st)::Pair{Int,eltype(str)}
  isspace(c) || break
  popfirst!(st)
  end
  elseif interpolate && !in_single_quotes && c == '$'
- i = consume_upto(s, i, j)
+ i = consume_upto!(arg, s, i, j)
  isempty(st) && error("\$ right before end of command")
- stpos, c = popfirst!(st)
+ stpos, c = popfirst!(st)::Pair{Int,eltype(str)}
  isspace(c) && error("space not allowed right after \$")
  if startswith(SubString(s, stpos), "var\"")
  # Disallow var"#" syntax in cmd interpolations.
@@ -75,28 +76,28 @@ function shell_parse(str::AbstractString, interpolate::Bool=true;
  ex, j = Meta.parseatom(s, stpos, filename=filename)
  end
  last_parse = (stpos:prevind(s, j)) .+ s.offset
- update_arg(ex);
+ push_nonempty!(arg, ex)
  s = SubString(s, j)
  Iterators.reset!(st, pairs(s))
  i = firstindex(s)
  else
  if !in_double_quotes && c == '\''
  in_single_quotes = !in_single_quotes
- i = consume_upto(s, i, j)
+ i = consume_upto!(arg, s, i, j)
  elseif !in_single_quotes && c == '"'
  in_double_quotes = !in_double_quotes
- i = consume_upto(s, i, j)
+ i = consume_upto!(arg, s, i, j)
  elseif c == '\\'
  if in_double_quotes
  isempty(st) && error("unterminated double quote")
  k, c′ = peek(st)
  if c′ == '"' || c′ == '$' || c′ == '\\'
- i = consume_upto(s, i, j)
+ i = consume_upto!(arg, s, i, j)
  _ = popfirst!(st)
  end
  elseif !in_single_quotes
  isempty(st) && error("dangling backslash")
- i = consume_upto(s, i, j)
+ i = consume_upto!(arg, s, i, j)
  _ = popfirst!(st)
  end
  elseif !in_single_quotes && !in_double_quotes && c in special
@@ -108,8 +109,8 @@ function shell_parse(str::AbstractString, interpolate::Bool=true;
  if in_single_quotes; error("unterminated single quote"); end
  if in_double_quotes; error("unterminated double quote"); end
 
- update_arg(s[i:end])
- append_arg()
+ push_nonempty!(arg, s[i:end])
+ append_2to1!(args, arg)
 
  interpolate || return args, last_parse