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Date: Mon, 30 May 2011 15:52:40 +0200
From: Georg Bauhaus <rm.dash-bauhaus@futureapps.de>
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Subject: Re: Tentative design of markdown parser
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Date: 2011-05-30T15:52:41+02:00
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On 28.05.11 15:22, Natasha Kerensikova wrote:

> This is actually the only point I don't like about the design: there
> should be a way to check at compile time that in a Span_Element the
> Renderer_Callback can actually handle what is produced by the
> Lexer_Callback. However I can't find any.

When I know all the types of objects that Lexer_Callback
can produce, I like to list them in an enumeration type,
type Token_Kind is (A, B, C, ...).
 Then, in every object of

type Renderer_Callback is access procedure (
   Token : Token_Root'Class);

I'd use case coverage to make sure that it will handle
Token: the enumeration value is a component of Token,
or else I call a function on Token that returns its
Token_Kind.