Merge pull request #3376 from TheAnonymous/devel

Added examples in documenation for add del delete repr insert sizeof high low

lib/system.nim

@@ -221,11 +221,21 @@ proc high*[T](x: T): T {.magic: "High", noSideEffect.}
   ## the highest possible value of an ordinal value `x`. As a special
   ## semantic rule, `x` may also be a type identifier.
   ## ``high(int)`` is Nim's way of writing `INT_MAX`:idx: or `MAX_INT`:idx:.
+  ##
+  ## .. code-block:: nim
+  ##  var arr = [1,2,3,4,5,6,7]
+  ##  high(arr) #=> 6
+  ##  high(2) #=> 9223372036854775807
 
 proc low*[T](x: T): T {.magic: "Low", noSideEffect.}
   ## returns the lowest possible index of an array, a sequence, a string or
   ## the lowest possible value of an ordinal value `x`. As a special
   ## semantic rule, `x` may also be a type identifier.
+  ##
+  ## .. code-block:: nim
+  ##  var arr = [1,2,3,4,5,6,7]
+  ##  high(arr) #=> 0
+  ##  high(2) #=> -9223372036854775808
 
 type
   range*{.magic: "Range".}[T] ## Generic type to construct range types.
@@ -584,6 +594,10 @@ proc sizeof*[T](x: T): int {.magic: "SizeOf", noSideEffect.}
   ## its usage is discouraged - using ``new`` for the most cases suffices
   ## that one never needs to know ``x``'s size. As a special semantic rule,
   ## ``x`` may also be a type identifier (``sizeof(int)`` is valid).
+  ##
+  ## .. code-block:: nim
+  ##  sizeof('A') #=> 1
+  ##  sizeof(2) #=> 8
 
 when defined(nimtypedescfixed):
   proc sizeof*(x: typedesc): int {.magic: "SizeOf", noSideEffect.}
@@ -705,12 +719,22 @@ template excl*[T](s: var set[T], flags: set[T]) =
 proc card*[T](x: set[T]): int {.magic: "Card", noSideEffect.}
   ## returns the cardinality of the set ``x``, i.e. the number of elements
   ## in the set.
+  ##
+  ## .. code-block:: nim
+  ##  var i = {1,2,3,4}
+  ##  card(i) #=> 4
 
 proc ord*[T](x: T): int {.magic: "Ord", noSideEffect.}
   ## returns the internal int value of an ordinal value ``x``.
+  ##
+  ## .. code-block:: nim
+  ##  ord('A') #=> 65
 
 proc chr*(u: range[0..255]): char {.magic: "Chr", noSideEffect.}
   ## converts an int in the range 0..255 to a character.
+  ##
+  ## .. code-block:: nim
+  ##  chr(65) #=> A
 
 # --------------------------------------------------------------------------
 # built-in operators
@@ -1315,6 +1339,10 @@ proc add *[T](x: var seq[T], y: openArray[T]) {.noSideEffect.} =
   ## containers should also call their adding proc `add` for consistency.
   ## Generic code becomes much easier to write if the Nim naming scheme is
   ## respected.
+  ##
+  ## .. code-block:: nim
+  ##   var s: seq[string] = @["test2","test2"]
+  ##   s.add("test") #=> @[test2, test2, test]
   let xl = x.len
   setLen(x, xl + y.len)
   for i in 0..high(y): x[xl+i] = y[i]
@@ -1329,6 +1357,10 @@ proc shallowCopy*[T](x: var T, y: T) {.noSideEffect, magic: "ShallowCopy".}
 proc del*[T](x: var seq[T], i: Natural) {.noSideEffect.} =
   ## deletes the item at index `i` by putting ``x[high(x)]`` into position `i`.
   ## This is an O(1) operation.
+  ##
+  ## .. code-block:: nim
+  ##  var i = @[1,2,3,4,5]
+  ##  i.del(2) #=> @[1, 2, 5, 4]
   let xl = x.len - 1
   shallowCopy(x[i], x[xl])
   setLen(x, xl)
@@ -1336,6 +1368,10 @@ proc del*[T](x: var seq[T], i: Natural) {.noSideEffect.} =
 proc delete*[T](x: var seq[T], i: Natural) {.noSideEffect.} =
   ## deletes the item at index `i` by moving ``x[i+1..]`` by one position.
   ## This is an O(n) operation.
+  ##
+  ## .. code-block:: nim
+  ##  var i = @[1,2,3,4,5]
+  ##  i.delete(2) #=> @[1, 2, 4, 5]
   template defaultImpl =
     let xl = x.len
     for j in i..xl-2: shallowCopy(x[j], x[j+1])
@@ -1351,6 +1387,10 @@ proc delete*[T](x: var seq[T], i: Natural) {.noSideEffect.} =
 
 proc insert*[T](x: var seq[T], item: T, i = 0.Natural) {.noSideEffect.} =
   ## inserts `item` into `x` at position `i`.
+  ##
+  ## .. code-block:: nim
+  ##  var i = @[1,2,3,4,5]
+  ##  i.insert(2,4) #=> @[1, 2, 3, 4, 2, 5]
   template defaultImpl =
     let xl = x.len
     setLen(x, xl+1)
@@ -1371,6 +1411,12 @@ proc repr*[T](x: T): string {.magic: "Repr", noSideEffect.}
   ## takes any Nim variable and returns its string representation. It
   ## works even for complex data graphs with cycles. This is a great
   ## debugging tool.
+  ##
+  ## .. code-block:: nim
+  ##  var s: seq[string] = @["test2","test2"]
+  ##  var i = @[1,2,3,4,5]
+  ##  repr(s) #=> 0x1055eb050[0x1055ec050"test2", 0x1055ec078"test2"]
+  ##  repr(i) #=> 0x1055ed050[1, 2, 3, 4, 5]
 
 type
   ByteAddress* = int