lambda expression in boo

Question

dose boo understand Expression tree?

I try to compile this line with sharp develop

exp as System.Linq.Expressions.Expression[of Func[of SomeClass, bool]] = { p as Text | return (p.Name == 'tttt') }

but sharp develop raised this error

Cannot convert 'callable(testlinq.SomeClass) as bool' to 'System.Linq.Expressions.Expression[of System.Func[of testlinq.SomeClass, bool]]'. (BCE0022)

Assuming you meant "lambda", not "[lambada](http://en.wikipedia.org/wiki/Lambada)" — John Saunders, Aug 09 '11 at 04:53
Now I'm sort of disappointed that we've been calling them lambdas all these years. Lambada has much more vibrance. — Jordan, Aug 09 '11 at 04:57
what is boo? I can't see any reference to boo in the code, and why is boo used as a tag? — Tomas Jansson, Aug 09 '11 at 09:17
@Tomas: that would seem to be google-worthy: [Boo - a wrist-friendly language for the CLI](http://boo.codehaus.org/Differences+with+Csharp) — sehe, Aug 09 '11 at 09:22

score 1 · Answer 1 · answered Aug 09 '11 at 09:18

1

Boo has had expression trees longer than C#.

http://ayende.com/blog/3065/meta-methods

[Meta]
static def verify(expr as Expression):
    return [|
        unless $expr:
            raise $(expr.ToCodeString())
    |]

IIRC Boo was designed to allow meta-programming macro's (much like Lisp, Nemerle, and many other functional languages) and has as such allowed full access to the AST of any fragment of Boo code.

Now this is all served from long memory, so I advise you to consult the Boo documentation for up-to-date information.

answered Aug 09 '11 at 09:18

sehe

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Thanks but I mean lambda expression tree not AST – Aug 10 '11 at 07:52
A lambda expression tree is rather ambiguous; I guess you mean `System.Linq.Expressions.Expression`; If I'm not wrong the example page linked shows you exactly how to interoperate with that, but I might have been reading that wrong? – sehe Aug 10 '11 at 08:57

lambda expression in boo

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