logo
down
shadow

f# signature matching explained


f# signature matching explained

By : Stefan Ek
Date : November 17 2020, 01:00 AM
seems to work fine I think that part of the problem comes from mixing methods (OO style) and functions (FP style).
FP style functions have multiple parameters separated by spaces. OO style methods have parens and parameters separated by commas. Methods in other .NET libraries are always called using "tuple" syntax (actually subtly different from tuples though) and a tuple is considered to be one parameter.
code :
// wrap method call with function
let assertEqual x y = Assert.Equal(x,y)

// all FP-style functions
List.map2 assertEqual test1 test2
List.map2 (fun x y -> Assert.Equal(x,y)) test1 test2
printfn "%s" "hello".ToUpper()  
// Error: Successive arguments should be separated 
// by spaces or tupled
printfn "%s" ("hello".ToUpper())  // ok
printfn "%s" <| "hello".ToUpper() // ok
// wrap method call with function AND swap params
let contains searchFor (s:string) = s.Contains(searchFor)

// all FP-style functions
["a"; "b"; "c"]
|> List.filter (contains "a")


Share : facebook icon twitter icon
Matching JPEG signature

Matching JPEG signature


By : Ray Padilla
Date : March 29 2020, 07:55 AM
This might help you I am trying to scan a file looking for 1MB JPEGs that would be stored contiguously. My approach is create a structure to match the first 4 bytes with the JPEG signature and, if true, write the entire 512 buffer to a named file until I find another jpeg signature then I create a new file. The code below creates 2 files, neither of which are readable as the first few bytes are not part of the jpeg signature. Any ideas where I went wrong? I tried variations of my if statement where I test for the signature but no luck thus far. , Replace your second fread inside the loop with the below:
code :
        memcpy((void *)&myjpg, (void *) buffer, sizeof(JPGTEST));
Interface signature not matching

Interface signature not matching


By : Stephane Demers
Date : March 29 2020, 07:55 AM
like below fixes the issue Your IGrid interface is a function interface, meaning the interface describes a function. You can implement it like this:
code :
let yourFunc: IGrid = (gridCell: GridCell): boolean => {
    return true;
};
export interface IGrid {
    foo(gridCell: GridCell): boolean
}

class Grid implements IGrid {
    foo(gridCell: GridCell): boolean {
        return true;
    }
}
Error: No matching signature for function IF for argument types: BOOL. Supported signature: IF(BOOL, ANY, ANY)

Error: No matching signature for function IF for argument types: BOOL. Supported signature: IF(BOOL, ANY, ANY)


By : user2749018
Date : March 29 2020, 07:55 AM
should help you out I'm trying to count the number of times a "rating" is above 9. Working in Google BigQuery with StandardSQL , You missplaced a parenthesis:
code :
SELECT 
COUNT(IF(survey_responses.survey_rating  >= 9,1,NULL))
   AS survey_responses_num_positives
Java Function andThen signature explained

Java Function andThen signature explained


By : shahram
Date : March 29 2020, 07:55 AM
hop of those help? The reason isn’t obvious when you use Integer, which is a final class and therefore cannot have a subclass.
Consider this:
code :
Function<Number, Number> f1 = x -> x.doubleValue() * 2;
Function<Double, Double> f2 = x -> x.doubleValue() * 3;

Number myApplyThen = (input) -> {
    Number y1 = f1.apply(input);
    Double y2 = f2.apply(y1);    // ERROR: f2 requires a Double!
};
PHP hash_hmac not matching AWS Signature 4 example

PHP hash_hmac not matching AWS Signature 4 example


By : Ethen Allen
Date : March 29 2020, 07:55 AM
I wish did fix the issue. I'm having an issue with hash_hmac and AWS signature version 4. I'm using the example they laid out here: http://docs.aws.amazon.com/general/latest/gr/sigv4-calculate-signature.html , The correct format is reverse:
shadow
Privacy Policy - Terms - Contact Us © ourworld-yourmove.org