iteratorFromFunction - uses null to mark end of stream [1006726]

< > BotCompany Repo | #1006726 // iteratorFromFunction - uses null to mark end of stream

JavaX fragment (include) [tags: use-pretranspiled]

// f: func -> A (stream ends when f returns null)
static <A> IterableIterator<A> iteratorFromFunction(fO f) {
  class IFF extends IterableIterator<A> {
    A a;
    bool done;
    
    public bool hasNext() {
      getNext();
      ret !done;
    }
    
    public A next() {
      getNext();
      if (done) fail();
      A _a = a;
      a = null;
      ret _a;
    }
    
    void getNext() {
      if (done || a != null) ret;
      a = (A) callF(f);
      done = a == null;
    }
  };
  ret new IFF;
}

// optimized version for F0 argument
ifclass F0
static <A> IterableIterator<A> iteratorFromFunction(F0<A> f) {
  ret iteratorFromFunction_f0(f);
}
endif

static <A> IterableIterator<A> iteratorFromFunction(IF0<A> f) {
  ret iteratorFromFunction_if0(f);
}

Author comment

Began life as a copy of #1005525

Travelled to 16 computer(s): aoiabmzegqzx, bhatertpkbcr, cbybwowwnfue, cfunsshuasjs, elmgxqgtpvxh, gwrvuhgaqvyk, irmadwmeruwu, ishqpsrjomds, lpdgvwnxivlt, mowyntqkapby, mqqgnosmbjvj, pyentgdyhuwx, pzhvpgtvlbxg, tslmcundralx, tvejysmllsmz, vouqrxazstgt

Snippet ID:

#1006726

Snippet name:

iteratorFromFunction - uses null to mark end of stream

Eternal ID of this version:

#1006726/10

Text MD5:

e89edc854bbc8f33b3de846a485709d6

Transpilation MD5:

32cef42f9ee9e52a84d41c3a0f13e169

Author:

stefan

Category:

javax

Type:

JavaX fragment (include)

Public (visible to everyone):

Yes

Archived (hidden from active list):

Created/modified:

2021-07-11 15:56:21

Source code size:

797 bytes / 38 lines

Pitched / IR pitched:

No / No

Views / Downloads:

572 / 698

Version history:

9 change(s)

Referenced in:

[show references]

1	// f: func -> A (stream ends when f returns null)
2	static <A> IterableIterator<A> iteratorFromFunction(fO f) {
3	class IFF extends IterableIterator<A> {
4	A a;
5	bool done;
6
7	public bool hasNext() {
8	getNext();
9	ret !done;
10	}
11
12	public A next() {
13	getNext();
14	if (done) fail();
15	A _a = a;
16	a = null;
17	ret _a;
18	}
19
20	void getNext() {
21	if (done \|\| a != null) ret;
22	a = (A) callF(f);
23	done = a == null;
24	}
25	};
26	ret new IFF;
27	}
28
29	// optimized version for F0 argument
30	ifclass F0
31	static <A> IterableIterator<A> iteratorFromFunction(F0<A> f) {
32	ret iteratorFromFunction_f0(f);
33	}
34	endif
35
36	static <A> IterableIterator<A> iteratorFromFunction(IF0<A> f) {
37	ret iteratorFromFunction_if0(f);
38	}