Arithmetic evaluation: Difference between revisions
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}
}</syntaxhighlight>
=={{header|Elixir}}==
In Elixir AST is a built-in feature.
<syntaxhighlight lang="elixir">
defmodule Ast do
def main do
expr = IO.gets("Give an expression:\n") |> String.Chars.to_string |> String.trim
case Code.string_to_quoted(expr) do
{:ok, ast} ->
IO.puts("AST is: " <> inspect(ast))
{result, _} = Code.eval_quoted(ast)
IO.puts("Result = #{result}")
{:error, {_meta, message_info, _token}} ->
IO.puts(message_info)
end
end
end
</syntaxhighlight>
{{out}}
<pre>
>elixir -e Ast.main()
Give an expression:
2*(4 - 1)
AST is: {:*, [line: 1], [2, {:-, [line: 1], [4, 1]}]}
Result = 6
>elixir -e Ast.main()
Give an expression:
2*(4 - 1) + (
missing terminator: ) (for "(" starting at line 1)
</pre>
=={{header|Emacs Lisp}}==
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