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[Daniele Filaretti <dfilaretti AT gmail.com>]

On 6 Feb 2013, at 18:19, Radu Mereuta <headness13 AT gmail.com> wrote:

Are you sure you don't have a priority relation between fcall and array? That might reject the correct parsing tree, and would explain why it works with [bracket].

Oh, well, in fact I had a precedence (I forgot to mention in my question). 

It was 

Exp[Exp] > Id (Exps)

And yes, if I remove the precedence it works. 

To be honest I don't understand why, parsing issues always confuse me :) 

(I mean, my _expression_ -- foo()[0] is an Exp[Exp]. And Exp[Exp] has the precedence. So there should not be any ambiguity I guess?)

Anyway, thanks a lot! 

Cheers, 

Daniele

On Wed, Feb 6, 2013 at 8:06 PM, Daniele Filaretti <dfilaretti AT gmail.com> wrote:

Hi all,
here is another question for you K hackers!

Let say my grammar contains something that looks like

> syntax Exp ::=
>    …
>    | Id "(" Exps ")" // function call
>    | Exp "[" Exp "]"  [seqstrict] // reading a field from an array (the first Exp must evaluate to an array value, the second to a key value)
>    …

and suppose I write a function, "foo()" that returns an array. Now, if in my program I write something like

> foo()[0];

I get a parsing error:

> [Error] Critical: Parse error: Syntax error near unexpected character ';'
>       File: test.php
>       Location: (5,9,5,9)


As an experiment, I tried to add

> syntax Exp ::= "(" Exp ")" [bracket]

and then, if I evaluate

> (foo())[0]:


it works!

Am I missing something or is a parsing problem?

Thanks a lot!

Cheers,
Daniele


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