[%wing p=(list limb)]
A wing is a limb search path into the subject.
A wing is a list of limbs (including a trivial list of one limb). The limbs are resolved in succession. The result of the last limb resolution is the value produced by the wing expression.
a.b.c. Read this as '
c'. Finds limb
a within limb
b within limb
c of the subject.
Intuitively, Hoon wings are written in the opposite order from attribute dot-paths in most languages. Hoon
a.b.c is Java's
c.b.a; it means "a within b within c."
Any item in the wing can resolve to a leg (fragment) or arm (computation). But if a non-terminal item in the wing would resolve to an arm, it resolves instead to the subject of the arm -- in other words, the core exporting that name.
The mysterious idiom
..b produces the leg
b is a leg; the core exporting
b is an arm. Since
. is the same limb as
..b is the same wing as
~zod:dojo> =a [fod=3 bat=[baz=1 moo=2]]~zod:dojo> bat.a[baz=1 moo=2]~zod:dojo> moo.bat.a2
There are two common syntaxes used to resolve a wing path into the current subject:
. dot and
.dot syntax, as
c.b.a, resolves the wing path into the subject at the right hand using Nock 0 (or possibly Nock 9 or Nock 10 depending on the expression).> !,(*hoon c.b.a)[%wing p=~[%c %b %a]]
:col operator expands to a
=>tisgar to resolve the wing path against its right-hand side as the subject. This can be a Nock 7 or possibly optimized by the compiler to a Nock 0.> !,(*hoon c:b:a)[%tsgl p=[%wing p=~[%c]] q=[%tsgl p=[%wing p=~[%b]] q=[%wing p=~[%a]]]]