Hi,
I'm trying to make a syntax reference in the form
of source code. It's not ready, but if someone
shares the same ideas I could use some
help. (Should I put this on a wiki? Where?)
My “design principles” are:
• It should contain just pieces of uncommented
code. The idea is not to use it as a fast
tutorial, but as a reminder of how to write all
kinds of things, and solve all questions of type
“is this allowed?”;
• It should be small, and fit on a printed A4
page;
• It should show the complete syntax of
everything, not the most common. For instance,
‘case of’ should show the use of guards;
• It should be an example of valid code, not good
one. The idea is to show what can be done, not
what should :)
• It should use expanded code, not identation
rules. Replacement of identation for code (like
{} etc.) have simple rules, and the proper way
to ident can be deduced from expanded
code. Sometimes this is important if we are
trying to solve syntax errors;
• It should use Unicode. It's nice to know which
kind of Unicode characters can actually be
used;
• It should use no predefined types or classes
except Bool. I’ll write a Prelude code reference
if this first attempt go right.
So I came up with the weird code below. It should
contain a lot more, and be more dense (more syntax
examples per lines of code), but it's already
usefull for a begginer like me. What do you think?
Best,
Maurício
module Ça (Exèmplo(Åwirù,Øwet'Л,Øwet'И),aҝҧү,Clááá) where {
class Clááá ú where {
(⊗) :: ú -> ú -> ú;
τAmber :: ú -> ú;
τAmber a = a ⊗ a;
};
data D١ = U1 | U2 | U3; data D٢ = Vú1 | Vú2 | JustVú;
data D٤ = Opção | OutraOpção;
data Exèmplo = Åwirù | Øwet'Л D٤ | Øwet'И D٢ Exèmplo;
osmesmos :: D٤ -> D٤ -> Bool;
osmesmos Opção Opção = True; osmesmos OutraOpção OutraOpção = True;
osmesmos _ _ = False;
aҝҧү = (Øwet'И Vú2 aҝҧү) ⊗ Åwirù;
instance Clááá Exèmplo where {
Åwirù ⊗ _ = Åwirù;
a@(Øwet'Л b) ⊗ x = case x of {
Åwirù -> a;
y@(Øwet'Л o) | (osmesmos o Opção) -> a | otherwise -> Øwet'И Vú1 y;
y@(Øwet'И _ _) -> y ⊗ a
};
a@(Øwet'И Vú1 _) ⊗ _ = a;
a@(Øwet'И Vú2 x) ⊗ _ = x;
a@(Øwet'И JustVú _) ⊗ y = y;
}
}
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