I want to check if a line contains a specific word, so I tried to use the String.isSubstring function with the line and the specific word. But somehow that function dosn't work for me.
String.isSubstring("Hi my name is...", "name");
stdIn:2.1-2.47 Error: operator and operand don't agree [tycon mismatch]
operator domain: string
operand: string * string
in expression:
String.isSubstring ("Hi my name is...","name")
-
I will love if some one can tell me what did i do wrong?
Thanx
String.isSubstring is a curried function -- that is, its arguments are passed in separately, not as a tuple.
Try
String.isSubstring "Hi my name is..." "name"
Related
I have a single line code which removes trailing and leading whitespaces, and also replaces multiple spaces in between with a single space. (from a string)
value = value..trim()..split(" +")..join(" ");
However I am getting the following error.
The method 'join' isn't defined for the type 'String'.
Try correcting the name to the name of an existing method, or defining a method named 'join'.(dartundefined_method)
What i am doing wrong?
You don't need cascade notation there:
value = value.split(' ').where((x) => x.isNotEmpty).map((x) => x.trim()).join(" ")
I forgot adding RegExp.
value = value.trim().split(RegExp(" +")).join(" ");
is working!!
Need help with the below conversion in Talend:
"0.12900-" string to -0.12900 in float via Tmap expression.
I am not well versed with Java hence the difficulty.
You could try something like this :
row1.column.contains("-")?Float.parseFloat( "-"+ StringHandling.LEFT(row1.column,row1.column.length()-1)):Float.parseFloat(row1.column)
Float.parseFloat allows you to convert a string to a float type.
StringHandling.LEFT gets the first characters of a string, here the total length-1.
Ternary operator controls if your string contains "-", otherwise you just have to parse the "-" symbol
I'm using a library for string interning (string-cache), that uses macros to efficient create elements (atom!). However for simplification here is a similar macro that demonstrates the problem
macro_rules! string_intern {
("d") => ("Found D");
}
say I need to call this macro from another macro and give it a string version of an identifier.
macro_rules! print_ident {
($id:ident) => (
string_intern!(stringify!($id));
);
}
However calling this macro
fn main() {
print_ident!(d);
}
Fails with error:
error: no rules expected the token `stringify`
--> <anon>:7:24
|
7 | string_intern!(stringify!($id));
| ^^^^^^^^^
Playground link
I know stringify! correctly converts to identifier d to string "d", because giving it to println! works as expected. Is there a way to pass the identifier I want turned into string to string_intern?
println! lets you do this because it uses format_args! under the covers, which is a compiler-provided "intrinsic" that forcibly evaluates its first argument before using it. You cannot do this from a user-defined macro; you'd have to write a compiler plugin (which requires a nightly compiler and no guarantee of stability).
So, yeah; you can't. Sorry. The only thing you can do is redefine the macro in such a way that you don't need an actual string literal, or change how you invoke it.
Your definition of string_intern! is expecting a literal "d" and nothing else, but you are passing in these tokens: stringify, !, ... which why it fails. The definition of string_intern! that you want is probably:
macro_rules! string_intern {
($e:expr) => {
match $e {
"d" => "Found D",
_ => "Not found",
}
}
}
which can accept any expression that evaluates to a string type.
I am new to coffee script. When I am looking at this document https://atom.io/docs/api/v0.198.0/CommandRegistry#instance-add
I see a code segment like,
atom.commands.add 'atom-text-editor',
'user:insert-date': (event) ->
editor = #getModel()
editor.insertText(new Date().toLocaleString())
while the function signature looks,
::add(target, commandName, callback)
So in the code segment, what does : on the second line mean? My understanding is the 'user:insert-date' before : is commandName in the signature. The thing after : is "callback". So : is a argument separator like a ,? I don't find this introduced in the coffee script document http://coffeescript.org
That colon is just part of an object literal. The braces around object literals are optional in CoffeeScript when there's no ambiguity. If we add the optional braces, we get something that looks more like JavaScript:
atom.commands.add 'atom-text-editor', {
'user:insert-date': (event) ->
#...
}
So atom.commands.add is being called with two arguments. The first is the string 'atom-text-editor' and the second is an object with one key ('user:insert-date') whose value is an anonymous function that takes a single argument.
Appending mu is too short's answer (the user is absolutely correct that the second parameter commandNamecan be an object without the explicit braces {})
Atom's sourcecode:
https://github.com/atom/atom/blob/v0.198.0/src/command-registry.coffee#L81
add: (target, commandName, callback) ->
if typeof commandName is 'object'
commands = commandName
disposable = new CompositeDisposable
for commandName, callback of commands
disposable.add #add(target, commandName, callback)
return disposable
Lets assume I have the following Java code:
public String foo()
{
// returns foo()
String log = "foo() : Logging something!"
return log;
}
Can I search in Eclipse for foo() occurring only in a String literal, but not anywhere else in the code? So in the example here Eclipse should only find the third occurrance of foo(), not the first one, which is a function name and not the second one, which is a comment.
Edit: Simple Regular Expressions won't work, because they will find foo() in a line like
String temp = "literal" + foo() + "another literal"
But here foo() is a function name and not a String literal.
You can try it like this:
"[^"\n]*foo\\(\\)[^"\n]*"
You have to escape brackets, plus this regex do not match new lines or additional quotes, which prevent wrong matches.
Maybe you should use regex to find any occurence of foo() between two " ?