crystal-lang/crystal

The Crystal programming language | http://crystal-lang.org | Fund Crystal's development: http://is.gd/X7PRtI | Docs: http://crystal-lang.org/docs/ | API: http://crystal-lang.org/api/

Ali Naqvi

@naqvis

"\u{ff}\u{fe}" if two separate chars

https://carc.in/#/r/bhhm

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@FromIRC

<postmodern> ah, weird syntax but that seems to work

<postmodern> ah but that defines a unicode string of four bytes. i need a two-byte string of 0xff and 0xfe

Ali Naqvi

@naqvis

"\xff\xfe" is actually two byte String

pp "\xff\xfe".to_slice # => Bytes[255, 254]

can you please describe, what are you getting? and what's your expected output?

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@FromIRC

<postmodern> i think the problem is because my code is using String#chars which returns unicode characters

Ali Naqvi

@naqvis

but FF FE is a UTF16-LE BOM

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@FromIRC

<postmodern> yeah, kind of wish Crystal had a way to forcibly defining an ASCII string, so you can contain non-UTF binary strings of random data that could be misinterpreted as UTF codepoints

Ali Naqvi

@naqvis

pp "\u{ff}\u{fe}".chars # => ['ÿ', 'þ']

this is correct representation

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@FromIRC

<postmodern> bytes shows extra unicode stuff in there [195, 191, 195, 190]

George Dietrich

@Blacksmoke16

are they multibyte chars?

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@FromIRC

<postmodern> they shouldn't be, but i guess they are being interpreted as such

Ali Naqvi

@naqvis

since String is UTF-8 but you are dealing with UTF-16

so you should be invoking "\u{ff}\u{fe}".to_utf16 to get the correct byte representation

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@FromIRC

<postmodern> crystal's utf8-by-default Strings are making it hard for me to define a String of garbage ASCII data

George Dietrich

@Blacksmoke16

https://crystal-lang.org/api/master/String.html#non-utf-8-valid-strings

Ali Naqvi

@naqvis

for encoding other than UTF-8 you should be using stream instead of String

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@FromIRC

<postmodern> ah ha, thanks

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@FromIRC

<postmodern> curious why String.new(Bytes[0xff, 0xfe]).chars.map(&.ord) returns [65533, 65533]

<postmodern> ah ha, i probably want to check String#valid_encoding? and check String#chars otherwise check String#bytes.

Ali Naqvi

@naqvis

its because that's not valid UTF-8

String.from_utf16("\u{ff}\u{fe}".to_utf16).chars.map(&.ord) # => [255, 254]

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@FromIRC

<postmodern> well got specs passing. good enough for now.

<jhass[m]> I still wish we kept String at enforced valid UTF-8 only and instead developed better tooling around Bytes

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@FromIRC

<jhass[m]> the dual use of String as character and byte array is a C ism that has no real place in a high level language IMO. It's probably my biggest gripe with Ruby

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@FromIRC

<postmodern> as long as you don't end up going the route of python3's byte arrays vs utf8 strings. that seems to be creating a lot of friction.

<postmodern> i'd be happy if String#valid_encoding? # => false, then the String would fallback to raw ASCII where #chars would be the ASCII bytes converted to ASCII 8bit chars.

<postmodern> seems a bit magic with how String tries its best to convert non-UTF byte sequences to UTF chars. idk, i need to sleep.

didactic-drunk

@didactic-drunk

How do you get a String Class::Name.method_name from a macro for the current method?

George Dietrich

@Blacksmoke16

{{"#{@type.name.id}.#{@def.name.id}".id}} would prob do it

didactic-drunk

@didactic-drunk

@what for the caller?

George Dietrich

@Blacksmoke16

is Class::Name the same as the class the method is in?

didactic-drunk

@didactic-drunk

First example didn't quiet work

class Foo
  macro foo
    p "{{"#{@type.name.id}.#{@def.name.id}".id}}"
  end
end

class Bar
  def bar
    Foo.foo
  end
end

Bar.new.bar => "Foo.bar"
# Should print "Bar.bar"

George Dietrich

@Blacksmoke16

https://play.crystal-lang.org/#/r/bhl6

didactic-drunk

@didactic-drunk

My more complex code shows Foo.bar

George Dietrich

@Blacksmoke16

got a link?

didactic-drunk

@didactic-drunk

Not published, I'll work on it

George Dietrich

@Blacksmoke16

the \{{ is impt

otherwise the macro expression is evaluated within the macro def

Ramakrishnan Vasantha Gopal

@vgramkris

hey, new here, posting some general questions out here.
Any reason why String.to_i32! is not implemented?

a : Int64 = (Int32::MAX).to_i64 + 1
b : Int32 | Nil = a.to_i32!
c : String = a.to_s
d : Int32 | Nil = c.to_i32!  # Error: undefined method 'to_i32!' for String

George Dietrich

@Blacksmoke16

what would to_i32! to diff than .to_i32?

do diff*

Ramakrishnan Vasantha Gopal

@vgramkris

if you see above, in line 2, assignment to be works fine

but line 4 is an issue

George Dietrich

@Blacksmoke16

right, can't you just call c.to_i32?

Ramakrishnan Vasantha Gopal

@vgramkris

so if the String cannot be typecasted to i32 then i expect nil instead of a exception

George Dietrich

@Blacksmoke16

it'll raise on over/under flow iirc

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