Cannot use try / with blocks inside sequence expressions. How to get around it?

» .net » Cannot use try / with blocks inside sequence expressions. How to get around it?

By : hemanth

Date : November 21 2020, 12:01 PM

Any of those help I think the answer from Gene is probably the way to go! But if you wanted to use sequence expressions to iterate over elements of a sequence that you already have, you could write something like this:

code :

let takeWhileNonException (input:seq<_>) = seq { 
  use ps = input.GetEnumerator()
  while (try ps.MoveNext() with _ -> false) do 
    yield ps.Current }

pentagonalSeq
|> takeWhileNonException
|> Seq.last

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How do I fold code for comment blocks inside method blocks?

By : user3045793

Date : March 29 2020, 07:55 AM

To fix the issue you can do Select the block that you want to hide Ctrl+M+H
This needs to be done only once. The block will become collapsible afterwards.

How to PARSE a sequence of items where items not in blocks are handled like single element blocks?

By : TORO

Date : March 29 2020, 07:55 AM

To fix this issue I hope the following can be the basis for your solution.
The following performs exactly the same in both R2 and R3. PARSE's 'into operation is VERY different between the two so I put a simple guard [.here.: block! :.here.] which fixes different bug situations in both platforms.

code :

rebol [
    author: "Maxim Olivier-Adlhoch"
    date: 2014-02-08
    license: "public domain"
]


A: [
    [{Foo}]
    [http://example.com/some/stuff.html]
    [separator]
]


B: {[
    {Foo}
    http://example.com/some/stuff.html
    separator
]}


C: [
    [{Foo} /some-refinement]
    [http://example.com/some/stuff.html {stuff caption} 3]
    [separator dashed-line]
]


D: [http://example.com/some/stuff.html [{Foo} /some-refinement] 3]


depth: ""
enter-block: func [][
    prin depth 
    print "[" 
    append depth "^-"
]

quit-block: func [][
    remove depth 
    prin depth 
    print "]"
]

emit-value: func [value][
    prin depth 
    probe value
]

=enter-block?=: none

=block=: [
    (
        =enter-block?=: [into =block=] ; we enter blocks by default
        enter-block
    )
    some [
        .here.: block! :.here. ; only enter blocks (R3/R2 compatible)
        (if 1 = length? .value.: first .here. [ =enter-block?=: [skip]  emit-value first .value. ])
        =enter-block?=
        | set .value. skip ( emit-value .value. )
    ]
    (quit-block)
]

STRING-HANDLER: func [data][
    if string? data [
        data: load data
    ]

    parse data =block=
]

STRING-HANDLER A
STRING-HANDLER B
STRING-HANDLER C
STRING-HANDLER D

ask "press enter to quit ..."

R: sequence of substituted expressions from sequence of values

By : user3640784

Date : March 29 2020, 07:55 AM

wish helps you I want to produce , Try bquote:

code :

lapply(as.numeric(2:7), function(x) bquote(10^.(x)))

How are expressions allowed inside Haskell do blocks

By : Vikas Parmar

Date : March 29 2020, 07:55 AM

To fix the issue you can do I'm going to crib from my very similar answer here (though probably not a duplicate since that question doesn't explicitly deal with let).
The Report gives a full translation from do syntax into kernel Haskell; the parts relevant to your question are:

code :

do {e}                = e
do {e;stmts}          = e >> do {stmts}
do {let decls; stmts} = let decls in do {stmts}

doubleX x = do                                                                                                                                                                                                                    
  putStrLn ("I will now double " ++ (show x))                                                                                                                                                                                     
  let double = x * 2                                                                                                                                                                                                              
  putStrLn ("The result is " ++ (show double))

==> do {e;stmts} rule

doubleX x =
  putStrLn ("I will now double " ++ (show x)) >> do
  let double = x * 2                                                                                                                                                                                                              
  putStrLn ("The result is " ++ (show double))

==> do {let decls; stmts} rule

doubleX x =
  putStrLn ("I will now double " ++ (show x)) >>
  let double = x * 2 in do
  putStrLn ("The result is " ++ (show double))

==> do {e} rule

doubleX x =
  putStrLn ("I will now double " ++ (show x)) >>
  let double = x * 2 in
  putStrLn ("The result is " ++ (show double))

How do I fold code for comment blocks inside method blocks in the Eclipse IDE

By : user2482547

Date : March 29 2020, 07:55 AM

I think the issue was by ths following , There is no such support in Eclipse, unfortunately. There is a request for this though, reported in 2008 with only 10 votes, so I would not expect it implemented any time soon.
Mentions of an Eclipse folding plugin called Coffee Bytes can be found, but most links are broken. Looks like latest Eclipse versions are not supported and the project looks discontinued.