diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/core/macros.nim | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/lib/core/macros.nim b/lib/core/macros.nim index 2b0d74e6a..79195966e 100644 --- a/lib/core/macros.nim +++ b/lib/core/macros.nim @@ -176,6 +176,21 @@ proc `[]=`*(n: NimNode, i: BackwardsIndex, child: NimNode) = ## set `n`'s `i`'th child to `child`. n[n.len - i.int] = child +template `or`*(x, y: NimNode): NimNode = + ## Evaluate ``x`` and when it is not an empty node, return + ## it. Otherwise evaluate to ``y``. Can be used to chain several + ## expressions to get the first expression that is not empty. + ## + ## .. code-block:: nim + ## + ## let node = mightBeEmpty() or mightAlsoBeEmpty() or fallbackNode + + let arg = x + if arg != nil and arg.kind != nnkEmpty: + arg + else: + y + proc add*(father, child: NimNode): NimNode {.magic: "NAdd", discardable, noSideEffect, locks: 0.} ## Adds the `child` to the `father` node. Returns the @@ -1433,4 +1448,3 @@ proc getProjectPath*(): string = discard ## Returns the path to the currently compiling project, not to ## be confused with ``system.currentSourcePath`` which returns ## the path of the current module. - |