# std/strbasics

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This module provides some high performance string operations.

Experimental API, subject to change.

# Procs

    proc add(x: var string; y: openArray[char]) {....raises: [], tags: [].}

  Concatenates `x` and `y` in place. `y` must not overlap with `x` to allow future `memcpy` optimizations. Source Edit

    func setSlice(s: var string; slice: Slice[int]) {....raises: [], tags: [].}

  Inplace version of `substr`.

  Example:

      import std/sugar

      var a = "Hello, Nim!"
      doAssert a.dup(setSlice(7 .. 9)) == "Nim"
      doAssert a.dup(setSlice(0 .. 0)) == "H"
      doAssert a.dup(setSlice(0 .. 1)) == "He"
      doAssert a.dup(setSlice(0 .. 10)) == a
      doAssert a.dup(setSlice(1 .. 0)).len == 0
      doAssert a.dup(setSlice(20 .. -1)).len == 0

      doAssertRaises(AssertionDefect):
        discard a.dup(setSlice(-1 .. 1))

      doAssertRaises(AssertionDefect):
        discard a.dup(setSlice(1 .. 11))

  Source Edit

    func strip(a: var string; leading = true; trailing = true;
               chars: set[char] = whitespaces) {.inline, ...raises: [], tags: [].}

  Inplace version of `strip`. Strips leading or trailing `chars` (default: whitespace characters).

  If `leading` is true (default), leading `chars` are stripped. If `trailing` is true (default), trailing `chars` are stripped. If both are false, the string is unchanged.

  Example:

      var a = "  vhellov   "
      strip(a)
      assert a == "vhellov"

      a = "  vhellov   "
      a.strip(leading = false)
      assert a == "  vhellov"

      a = "  vhellov   "
      a.strip(trailing = false)
      assert a == "vhellov   "

      var c = "blaXbla"
      c.strip(chars = {'b', 'a'})
      assert c == "laXbl"
      c = "blaXbla"
      c.strip(chars = {'b', 'a', 'l'})
      assert c == "X"

  Source Edit