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|
defmodule Makeup.Lexer.Groups do
@moduledoc """
Utilities to highlight groups of tokens on mouseover.
The typical example is to highlight matching pairs of delimiters,
such as parenthesis, angle brackets, etc.
"""
defp make_match([] = _patterns, _varnames, rest_of_tokens_varname) do
quote do
unquote(Macro.var(rest_of_tokens_varname, __MODULE__))
end
end
defp make_match([pattern | patterns], [varname | varnames], rest_of_tokens_varname) do
var = Macro.var(varname, __MODULE__)
quote do
[
unquote(pattern) = unquote(var)
| unquote(make_match(patterns, varnames, rest_of_tokens_varname))
]
end
end
defp put_group_ids([], _group_id_varname) do
quote(do: [])
end
defp put_group_ids(tokens, group_id_varname) do
group_id = Macro.var(group_id_varname, __MODULE__)
for {ttype_varname, attr_varname, text_varname} <- tokens do
ttype = Macro.var(ttype_varname, __MODULE__)
attr = Macro.var(attr_varname, __MODULE__)
text = Macro.var(text_varname, __MODULE__)
quote do
{
unquote(ttype),
Map.put(
unquote(attr),
# The Map key (an atom)
unquote(group_id_varname),
# The variable holding the value
unquote(group_id)
),
unquote(text)
}
end
end
end
defp open_branch(stack_name, pattern, group_prefix_varname, group_nr_varname) do
group_nr = Macro.var(group_nr_varname, __MODULE__)
group_prefix = Macro.var(group_prefix_varname, __MODULE__)
group_id = Macro.var(:group_id, __MODULE__)
rest_of_tokens = Macro.var(:rest_of_tokens, __MODULE__)
n = length(pattern)
token_varnames = for i <- 1..n, do: String.to_atom("token__#{i}")
ttype_varnames = for i <- 1..n, do: String.to_atom("ttype__#{i}")
attr_varnames = for i <- 1..n, do: String.to_atom("attr__#{i}")
text_varnames = for i <- 1..n, do: String.to_atom("text__#{i}")
tokens_data = Enum.zip([token_varnames, ttype_varnames, attr_varnames, text_varnames])
pattern_matches =
for {token_varname, ttype_varname, attr_varname, text_varname} <- tokens_data do
token = Macro.var(token_varname, __MODULE__)
ttype = Macro.var(ttype_varname, __MODULE__)
attr = Macro.var(attr_varname, __MODULE__)
text = Macro.var(text_varname, __MODULE__)
quote do
{unquote(ttype), unquote(attr), unquote(text)} = unquote(token)
end
end
tokens_pattern = make_match(pattern, token_varnames, :rest_of_tokens)
tokens_for_result = Enum.zip([ttype_varnames, attr_varnames, text_varnames])
head_tokens = put_group_ids(tokens_for_result, :group_id)
quote do
{stack, unquote(tokens_pattern)} ->
new_group_nr = unquote(group_nr) + 1
unquote(group_id) = unquote(group_prefix) <> "-" <> to_string(new_group_nr)
unquote_splicing(pattern_matches)
head_tokens = unquote(head_tokens)
head_of_stack = {unquote(stack_name), new_group_nr}
new_stack = [head_of_stack | stack]
{new_stack, new_group_nr, head_tokens, unquote(rest_of_tokens)}
end
end
defp close_branch(stack_name, pattern, group_prefix_varname, group_nr_varname) do
group_nr = Macro.var(group_nr_varname, __MODULE__)
group_prefix = Macro.var(group_prefix_varname, __MODULE__)
group_id = Macro.var(:group_id, __MODULE__)
rest_of_stack = Macro.var(:rest_of_stack, __MODULE__)
rest_of_tokens = Macro.var(:rest_of_tokens, __MODULE__)
n = length(pattern)
token_varnames = for i <- 1..n, do: String.to_atom("token__#{i}")
ttype_varnames = for i <- 1..n, do: String.to_atom("ttype__#{i}")
attr_varnames = for i <- 1..n, do: String.to_atom("attr__#{i}")
text_varnames = for i <- 1..n, do: String.to_atom("text__#{i}")
tokens_data = Enum.zip([token_varnames, ttype_varnames, attr_varnames, text_varnames])
pattern_matches =
for {token_varname, ttype_varname, attr_varname, text_varname} <- tokens_data do
token = Macro.var(token_varname, __MODULE__)
ttype = Macro.var(ttype_varname, __MODULE__)
attr = Macro.var(attr_varname, __MODULE__)
text = Macro.var(text_varname, __MODULE__)
quote do
{unquote(ttype), unquote(attr), unquote(text)} = unquote(token)
end
end
stack_pattern =
quote do
[{unquote(stack_name), current_group_nr} | unquote(rest_of_stack)]
end
tokens_pattern = make_match(pattern, token_varnames, :rest_of_tokens)
tokens_for_result = Enum.zip([ttype_varnames, attr_varnames, text_varnames])
head_tokens = put_group_ids(tokens_for_result, :group_id)
quote do
{unquote(stack_pattern), unquote(tokens_pattern)} ->
unquote(group_id) = unquote(group_prefix) <> "-" <> to_string(current_group_nr)
unquote_splicing(pattern_matches)
head_tokens = unquote(head_tokens)
{unquote(rest_of_stack), unquote(group_nr), head_tokens, unquote(rest_of_tokens)}
end
end
defp middle_branch(stack_name, pattern, group_prefix_varname, group_nr_varname) do
group_nr = Macro.var(group_nr_varname, __MODULE__)
group_prefix = Macro.var(group_prefix_varname, __MODULE__)
group_id = Macro.var(:group_id, __MODULE__)
rest_of_stack = Macro.var(:rest_of_stack, __MODULE__)
rest_of_tokens = Macro.var(:rest_of_tokens, __MODULE__)
n = length(pattern)
token_varnames = for i <- 1..n, do: String.to_atom("token__#{i}")
ttype_varnames = for i <- 1..n, do: String.to_atom("ttype__#{i}")
attr_varnames = for i <- 1..n, do: String.to_atom("attr__#{i}")
text_varnames = for i <- 1..n, do: String.to_atom("text__#{i}")
tokens_data = Enum.zip([token_varnames, ttype_varnames, attr_varnames, text_varnames])
pattern_matches =
for {token_varname, ttype_varname, attr_varname, text_varname} <- tokens_data do
token = Macro.var(token_varname, __MODULE__)
ttype = Macro.var(ttype_varname, __MODULE__)
attr = Macro.var(attr_varname, __MODULE__)
text = Macro.var(text_varname, __MODULE__)
quote do
{unquote(ttype), unquote(attr), unquote(text)} = unquote(token)
end
end
stack_pattern =
quote do
[{unquote(stack_name), current_group_nr} | unquote(rest_of_stack)]
end
tokens_pattern = make_match(pattern, token_varnames, :rest_of_tokens)
tokens_for_result = Enum.zip([ttype_varnames, attr_varnames, text_varnames])
head_tokens = put_group_ids(tokens_for_result, :group_id)
quote do
{unquote(stack_pattern) = stack, unquote(tokens_pattern)} ->
unquote(group_id) = unquote(group_prefix) <> "-" <> to_string(current_group_nr)
unquote_splicing(pattern_matches)
head_tokens = unquote(head_tokens)
{stack, unquote(group_nr), head_tokens, unquote(rest_of_tokens)}
end
end
defp branches_for_stack({stack_name, parts}) do
open_patterns = Keyword.fetch!(parts, :open)
middle_patterns = Keyword.get(parts, :middle, [])
close_patterns = Keyword.fetch!(parts, :close)
open_branches_ast =
Enum.map(
open_patterns,
fn pattern -> open_branch(stack_name, pattern, :group_prefix, :group_nr) end
)
middle_branches_ast =
Enum.map(
middle_patterns,
fn pattern -> middle_branch(stack_name, pattern, :group_prefix, :group_nr) end
)
close_branches_ast =
Enum.map(
close_patterns,
fn pattern -> close_branch(stack_name, pattern, :group_prefix, :group_nr) end
)
open_branches_ast ++ middle_branches_ast ++ close_branches_ast
end
@doc """
Defines a function with the given `name` that takes a list of tokens and divides
matching delimiters into groups.
Takes as arguments a `name` for the function (must be an atom) and a list
containing the patterns describing the matching groups.
## Examples
# Extracted from the default elixir lexer that ships with ExDoc
defgroupmatcher :match_groups, [
# Match opening and closing parenthesis
parentheses: [
open: [[{:punctuation, %{language: :elixir}, "("}]],
close: [[{:punctuation, %{language: :elixir}, ")"}]]
],
# Match more complex delimiters, but still an open and close delimiter
fn_end: [
open: [[{:keyword, %{language: :elixir}, "fn"}]],
close: [[{:keyword, %{language: :elixir}, "end"}]]
]
# Match delimiters with middle components
do_end: [
open: [
[{:keyword, %{language: :elixir}, "do"}]
],
middle: [
[{:keyword, %{language: :elixir}, "else"}],
[{:keyword, %{language: :elixir}, "catch"}],
[{:keyword, %{language: :elixir}, "rescue"}],
[{:keyword, %{language: :elixir}, "after"}]
],
close: [
[{:keyword, %{language: :elixir}, "end"}]
]
]
]
"""
defmacro defgroupmatcher(name, stacks, opts \\ []) do
name_helper =
name
|> Atom.to_string()
|> Kernel.<>("__helper")
|> String.to_atom()
branches =
stacks
|> Enum.map(&branches_for_stack/1)
|> List.flatten()
group_nr = Macro.var(:group_nr, __MODULE__)
unmatched_token_branch =
quote do
{old_stack, [token | toks]} ->
{old_stack, unquote(group_nr), [token], toks}
end
no_more_tokens_branch =
quote do
{old_stack, []} ->
{old_stack, unquote(group_nr), [], []}
end
all_branches = branches ++ unmatched_token_branch ++ no_more_tokens_branch
expr =
quote do
def unquote(name)(tokens, group_prefix \\ "group") do
unquote(name_helper)([], tokens, group_prefix, 0) |> :lists.flatten()
end
defp unquote(name_helper)(stack, tokens, group_prefix, group_nr) do
{new_stack, new_group_nr, head_tokens, rest_of_tokens} =
case {stack, tokens} do
unquote(all_branches)
end
case head_tokens do
[] ->
[]
_ ->
# Don't worry about the nested list, we'll flatten it later
[
head_tokens
| unquote(name_helper)(new_stack, rest_of_tokens, group_prefix, new_group_nr)
]
end
end
end
if Keyword.get(opts, :debug) do
expr
|> Macro.to_string()
|> Code.format_string!()
|> IO.puts()
end
expr
end
@doc """
Returns a random prefix for group ids in an HTML file.
This is useful to avoid collisions.
The group ids should be unique for a certain HTML document, and the easiest way of guaranteeing it
is by generating long random prefixes.
"""
def random_prefix(n), do: Enum.map(1..n, fn _ -> Enum.random(?0..?9) end) |> to_string
end
|
