On 12/12/22 7:54 PM, lili wrote:
is foreach Syntactic sugar?, like for-range in C++, if it is, compiler
how implement
Yes it is syntax sugar. The lowering depends on what the item you're
iterating is.
For an associative array `byKey`, it is converting the AA into a range
of keys, and for a range, the compiler does:
foreach(k; aa.byKey)
=>
for(auto r = aa.byKey, auto k = r.front; !r.empty; r.popFront)
(note that the declaration isn't valid syntax in D, but the compiler can
handle it)
How it's lowered isn't technically important, just know that it iterates
over each key.
-Steve
