Unique-Words Sigil

~u sigil · unique-word strings, lists, HTML classes, checked at compile time

Ideal for HTML classes used with templating systems such as Temple:

div class: ~u"flex items-center flex" do # (CompilerError) Duplicate word: flex
  p class: ~u"text-lg font-bold
              text-gray text-lg"  # ────── (CompilerError) Duplicate word: text-lg
  do                  #    └───── Effortless multiline classes promote readability
    "Hello world"     #          (~u automatically strips whitespace and newlines)
  end
end

Installation

Add unique_words_sigil to your list of dependencies in mix.exs:

def deps do
  [
    {:unique_words_sigil, "~> 0.1.0"}
  ]
end

then

mix deps.get

Start up a repl:

$ iex -S mix

iex> import UniqueWordsSigil

iex> ~u" hello  world "
"hello world"  # Whitespace trimmed, extra space & newlines ignored.

iex> ~u" hello  world hello  again"
** (ArgumentError) Duplicate word: hello  # Duplicate words prevented ⚔️

iex> {~u" hello  world "l, ~u" hello  world "a, ~u" hello  world "c}
{["hello", "world"], [:hello, :world], [~c"hello", ~c"world"]}
# String lists, atoms, charlists, oh my! (parity with ~w sigil)

Usage

~u"hello world"      -> "hello world"
~u" hello  world "   -> "hello world"  # whitespace is trimmed and "collapsed"
~u" hello  world "l  -> ["hello", "world"]
~u" hello  world "a  -> [:hello, :world]
~u" hello  world "c  -> [~c"hello", ~c"world"]
~u" hi     hi    "   -> (ArgumentError) Duplicate word: hi
~u" hi-hi  hi-hi "w  -> "hi-hi hi-hi"        Warning: Duplicate word: hi-hi
~u" hi     hi    "wl -> ["hi", "hi"]         Warning: Duplicate word: hi
~u" hi-hi  hi-hi "aw -> [:"hi-hi", :"hi-hi"] Warning: Duplicate word: hi-hi
~u" hi     hi    "cw -> [~c"hi", ~c"hi"]     Warning: Duplicate word: hi
                                                      ~~~~~~~~~~~~~~~~~~

~u works well with interpolation and multi-line strings:

a href: ~p"/link/url"
  class: ~u"flex items-center h-8 text-sm pl-8 pr-3
    #{if(@active, do: ~u"bg-slate", else: ~u"hover:bg-slate")}
    items-center text-blue"  # ────── Duplicate word: items-center
do          #  └───── Effortless multiline classes promote readability
   "Text"   #        (~u automatically strips whitespace and newlines)
end

Important

By default, interpolations WON'T be uniqueness-checked (they're unknown at compile-time).

i modifier may be added to check uniqueness of interpolated sections at runtime:

~u" hi hello \#{"h" <> "i"}"i -> (RuntimeError) Duplicate word: hi

Interpolation uniqueness-checking is disabled unless i modifier is set to avoid unintended runtime overhead.

When Mix.env() == :prod, interpolation uniqueness-checking will ALWAYS be disabled even when i modifier is set (this behavior caters to the most common use-case).

License

MIT