The Meteor Spacebar docs say "one can use parentheses to express the evaluation order of nested expressions" and give this example:
{{capitalize (getSummary post)}}
However, I get a error on build anytime I use parenthesis:
=> Errors prevented startup:
While building the application:
client/templates/test.html:6: Expected identifier, number, string,
boolean, or null
... {{capitalize (getSummary post)}} ...
This error does not occur when the parenthesis are removed; of course then the expressions aren't evaluated properly.
For context, this is my intention (using handlebar-helpers and meteor-roles)
{{#if $or (isInRole "someRole") (isInRole "someOtherRole")}}
<p>approved!</p>
{{/if}}
This is a new feature in 1.1.1; it is not available in 1.1.
Related
I am coding in R and due to stability purposes when I have to deploy something, I call every function with the syntax package::function(arguments) just to avoid conflicts that as you know may happen when using a lot of packages. It helped me a lot over the years.
I know that if is a reserved word so technically speaking it is impossible (or at least it should be in my knowledge) for someone to define an object and name it if.
I am also aware that it belongs to control flow statement (which I think are a different "thing") and due to the previous consideration I am also aware that the following questions might be useless. My pure technical doubts are:
Why if I embrace it in back-ticks the function class returns "function" as a result?
Why without back-ticks I get an error? and last but most important
Why I am unable to access it via the usual base::if() syntax?
As I said, most likely useless questions but at this point I am curious about the details underneath it.
> class(if)
Error: unexpected ')' in "class(if)"
> class(`if`)
[1] "function"
> base::if(T) T
Error: unexpected 'if' in "base::if"
> if(T) T
[1] TRUE
> base::if(`T`) T
Error: unexpected 'if' in "base::if"
if-with-backticks actually returns .Primitive("if")
The R language definition section on "Internal vs Primitive" specifies that .Primitive objects include
“Special functions” which really are language elements, but implemented as primitive functions:
{ ( if for while repeat break next
return function quote switch
The reason that a naked "if" without backticks or base::if don't work is that the "language elements" above are treated as special cases by R's parser. Once you have typed base::, R's parser expects the next symbol to be a regular symbol that can be looked up in the base namespace. base::if, base::for, and base::( all return errors because R does not expect these special elements to occur at this position in the input stream; they are syntactically incorrect.
Posting for two reasons: (1) I was stuck on unhelpful compiler errors for far too long for such a simple issue and I want the next person to google those messages to come upon my (or other) answers, and (2) I still don't understand disallowing a use clause, so my own answer is really incomplete.
In order to call a program in two places with mostly the same arguments, I want to use the '&' to append to a default list inline:
declare
Exit_Code : constant Integer := GNAT.OS_Lib.Spawn (Program_Name => "gprbuild", Args => (Default_GPR_Arguments & new String'(File_Name_Parameter)));
begin
if Exit_Code /= 0 then
raise Program_Error with "Exit code:" & Exit_Code'Image;
end if;
end;
However, the compiler complains that System.Strings.String_List needs a use clause:
operator for type "System.Strings.String_List" is not directly visible
use clause would make operation legal
But inserting use System.Strings.String_List yields:
"System.Strings.String_List" is not allowed in a use clause
I also got this warning:
warning: "System.Strings" is an internal GNAT unit
warning: use "GNAT.Strings" instead
So I substituted GNAT for System in the with and the use clause and got an extra error in addition to the original 'you need a use clause for System.Strings.String_List' one:
"GNAT.Strings.String_List" is not allowed in a use clause
Why is GNAT.Strings.String_List not allowed in a use clause? Section 8.5 on use clauses doesn't seem to state anything on disallowed packages, so is this a compiler bug? Is it possible to define a new package that cannot have a use clause?
In a use clause of the form
use Name;
Name must be a package name. GNAT.Strings.String_List is a subtype name, not a package name.
There are a number of ways to invoke "&" for String_List. The simplest is to use the full name:
GNAT.Strings."&" (Left, Right)
but presumably you want to be able to use it as an operator in infix notation, Left & Right. Ways to achieve this, in decreasing specificity:
function "&" (Left : GNAT.Strings.String_List; Right : GNAT.Strings.String_List) return GNAT.Strings.String_List renames GNAT.Strings."&"; This makes this specific function directly visible.
use type GNAT.Strings.String_List; This makes all primitive operators of the type directly visible.
use all type GNAT.Strings.String_List; This makes all primitive operations of the type (including non-operator operations) directly visible.
use GNAT.Strings; This makes everything in the package directly visible.
Looks like it is a design decision. And many other packages in System follows this rule. From the s-string.ads (package specification for System.String):
-- Note: this package is in the System hierarchy so that it can be directly
-- be used by other predefined packages. User access to this package is via
-- a renaming of this package in GNAT.String (file g-string.ads).
My guess why this is done in that way: because it isn't in the Ada specification, but extension from GNAT.
I'm getting an error "Did not check() all arguments". But I am checking all the arguments - very strange.
This Coffeescript code throws an error when you run the method:
Meteor.methods
doSomething : ( arg={} )->
check arg, Object
The problem turns out to be the argument default. The following code works:
Meteor.methods
doSomething : ( arg )->
check arg, Match.Maybe( Object )
arg ?= {}
This only seems to be a problem when you use empty object as an argument default. Other kinds of default argument seem to work - I tested null and list.
There's also a difference between calling:
Meteor.call "doSomething"
And calling this...
Meteor.call "doSomething", undefined
In the first case the argument is implicitly undefined, and will be set to a default. This bug does NOT happen.
In the second case we explicitly pass undefined (or null) and we get this bug. If you can avoid doing this, you won't need to change your arg defaults.
While working i met this annoying message
Strict Standards: Only variables should be passed by reference in G:\xampp\htdocs\MyProject\ZendSkeletonApplication\module\Admission\src\Admission\Controller\AdmissionController.php on line 107
My code
$consoldatedCities='';
array_walk_recursive($StateCityHash, function($cityName,$cityId) use(&$consoldatedCities){$consoldatedCities[$cityId] = $cityName; }); // line 107
This is to convert multidimensional array into simple array
But the code works as i expected.. can anyone tell me how to solve this problem
Here http://php.net/manual/en/language.references.pass.php it says that "There is no reference sign on a function call - only on function definitions." Try removing the '&' from your function call code there and see if that gets rid of the message.
---Edit---
Looking at this thread here "Strict Standards: Only variables should be passed by reference" error
you could try saving your callback function into a variable before passing it to the array walk function:
$consoldatedCities=array();
$callbackFcn=
function($cityName,$cityId) use(&$consoldatedCities)
{
$consoldatedCities[$cityId] = $cityName;
};
array_walk_recursive($StateCityHash, $callbackFcn);
Is there a way to "die" in execution flow in an xquery file and output a nicely formatted printout of a sequence variable?
I'm trying something like:
return { fn:error(xs:QName("ERROR"), $xml) }
but that doesn't quite seem to work.
Thanks!
Based on your comment (you need it for debugging) I guess you are looking for the fn:trace function, described here http://www.xqueryfunctions.com/xq/fn_trace.html
If you want to abort the execution flow and output an error in your application you should in fact use the XQuery exception handling.
Try something like this, omitting the return if this isn't part of a FLWOR expression.
...
return fn:error((), "DEBUG", $xml)
There's no need for curly braces unless you're enclosing an expression, for example <x>{ current-time() }</x>. The return expression is not enclosed.
With MarkLogic it's best to leave the first parameter of fn:error empty. That way you don't have to worry about a QName, and anyway some folks believe that it's reserved for predefined errors. MarkLogic uses the second parameter to fill in error:code, and the third parameter for data.
For more on fn:error, see http://docs.marklogic.com/fn:error and https://github.com/robwhitby/xray/pull/11