22 lines
573 B
Elixir
22 lines
573 B
Elixir
defmodule Blanks do
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def replace(ast, replacement) when not is_list(replacement), do: replace(ast, [replacement])
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def replace([do: ast], replacements), do: [do: replace(ast, replacements)]
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def replace(ast, replacements) do
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ast
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|> Macro.prewalk(replacements, &pre/2)
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|> elem(0)
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end
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defp pre(:__, [first | remainder]), do: {first, remainder}
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defp pre(node, acc), do: {node, acc}
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def count(ast) do
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ast
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|> Macro.prewalk(0, &count/2)
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|> elem(1)
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end
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defp count(:__, acc), do: {node, acc+1}
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defp count(node, acc), do: {node, acc}
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end
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