Mirror of forum.nim-lang.org

1356 :: ByteSeq to string ?

• redguy (orginal) [2015-06-22T22:49:36+02:00] view original

  Hello,

  New to nim. How do I change a bytes seq to a string efficiently ? I mean, no deep copying of the string. shallowCopy() somehow ?

  var list: seq[byte] = @[byte('a'), byte('b'), byte('c')]
  s = "as string: " & string(list) # Error: conversion from seq[byte] to string is invalid
  Run

  Of course string() above is wrong, I just wanted to write something.

  Thank you!

---

• Araq (orginal) [2015-06-22T22:55:21+02:00] view original

  There is no no-copy solution since string has in addition to a length field also a zero terminator for no-copy conversions to cstring. The solution is to not start with a seq[byte] in the first place when you need a string. Also with git devel string is compatible to openarray[char] so finally the stuff from sequtils works with strings.

---

• redguy (orginal) [2015-06-23T07:08:49+02:00] view original

  Thank you. So you mean, a string "is" or "acts like" a byte array ? If there are x0 chars in the string, will the RTL handle it accordingly ? functions like len() will work as expected ?

---

• Varriount (orginal) [2015-06-26T03:38:12+02:00] view original

  In Nim,a string is essentially a sequence of bytes, with a few bits of altered behavior. There is no distinction made for RTL vs LTR data.

---

• D0mler (orginal) [2020-07-16T18:31:56+02:00] view original

  out of curiosity, what is the risk of using caststring ?

---

• SolitudeSF (orginal) [2020-07-16T19:43:22+02:00] view original

  strings implicitly have terminating null byte for 0 copy conversion to c strings.

---