<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi!<div><br><div><div>On 6 jul 2012, at 18:28, Daniel Goertzen wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">While working with lists of fixed length, I noted that type specification for such lists are conspicuously missing. For example, the following does not work...<div><br></div><div><div><font face="'courier new', monospace">-spec get_buttons() -> {ok, [boolean(), boolean(), boolean(), boolean()]}.</font></div>
</div><div><br></div></blockquote>Try this:</div><div><br></div><div><div> -type buttons() :: [boolean() | [boolean() | [boolean() | [boolean() | []]]]].</div><div><br></div><div> -spec get_buttons() -> {ok, buttons()}.</div><div><br></div><div><div> get_buttons() -></div><div> [true | [false | [true | [false | [] ] ] ] ].</div><div><br></div><div>Of course my formatting of the get_buttons return value is intensional. You could write it</div><div>as normal [true,false,true,false].</div><div><br></div><div>You can of course write it as:</div><div><br></div><div>-spec get_buttons() -> {ok,[boolean() | [boolean() | [boolean() | [boolean() | []]]]] }.</div><div><br></div><div>Regards</div><div><br></div><div>/Tony</div></div><div><br></div><div><div><br></div></div><blockquote type="cite"><div>Is there some sneaky way to make this go? Now I know you would normally use a tuple in this situation, but I will be using the lists module to process this data so I want to stick with lists.</div>
<div><br></div><div>I would love to see something like this for list specification...</div><div><div><br></div><div><br></div><div><div><font face="'courier new', monospace"> List :: list(Type) %% Proper list ([]-terminated)</font></div>
<div><font face="'courier new', monospace">+ | list(Type, Length) %% Proper list of fixed size</font></div><div><font face="'courier new', monospace">+ | tlist(TList) %% Proper list specified like a tuple</font></div>
<div><font face="'courier new', monospace"> | improper_list(Type1, Type2) %% Type1=contents, Type2=termination</font></div><div><font face="'courier new', monospace"> | maybe_improper_list(Type1, Type2) %% Type1 and Type2 as above</font></div>
<div><font face="'courier new', monospace"><br></font></div><div><font face="'courier new', monospace"> Tuple :: tuple() %% stands for a tuple of any size</font></div><div><font face="'courier new', monospace"> | {}</font></div>
<div><font face="'courier new', monospace"> | {TList}</font></div><div><font face="'courier new', monospace"><br></font></div><div><font face="'courier new', monospace"> TList :: Type</font></div>
<div><font face="'courier new', monospace"> | Type, TList</font></div><div><br></div><div><br></div><div>Thanks,</div><div><span style="font-family:arial,helvetica,sans-serif">Dan.</span></div></div></div><div>
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