LazyValueTreeMap [1008857]

< > BotCompany Repo | #1008857 // LazyValueTreeMap

JavaX fragment (include)

sclass LazyValueTreeMap<A, B> extends TreeMap<A, B> {
  static O placeholder = new O; // fool type system
  O valueMaker;
  
  *(Collection<A> keys, O *valueMaker) {
    for (A key : unnull(keys)) put(key, (B) placeholder);
  }
  
  public B get(O key) {
    B value = super.get(key);
    if (value == placeholder)
      put((A) key, value = (B) callF(valueMaker, key));
    ret value;
  }
  
  int numPlaceholders() {
    ret countOccurrences_id(values(), placeholder);
  }
  
  // revert to identity hashcode
  public bool equals(O o) { ret this == o; }
  public int hashCode() { ret systemHashCode(this); }
}

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Snippet ID:

#1008857

Snippet name:

LazyValueTreeMap

Eternal ID of this version:

#1008857/9

Text MD5:

ccd726f33cf327886fce159b106a2cff

Author:

stefan

Category:

javax

Type:

JavaX fragment (include)

Public (visible to everyone):

Yes

Archived (hidden from active list):

Created/modified:

2017-06-14 14:01:58

Source code size:

633 bytes / 23 lines

Pitched / IR pitched:

No / No

Views / Downloads:

791 / 1801

Version history:

8 change(s)

Referenced in:

[show references]

1	sclass LazyValueTreeMap<A, B> extends TreeMap<A, B> {
2	static O placeholder = new O; // fool type system
3	O valueMaker;
4
5	(Collection<A> keys, O valueMaker) {
6	for (A key : unnull(keys)) put(key, (B) placeholder);
7	}
8
9	public B get(O key) {
10	B value = super.get(key);
11	if (value == placeholder)
12	put((A) key, value = (B) callF(valueMaker, key));
13	ret value;
14	}
15
16	int numPlaceholders() {
17	ret countOccurrences_id(values(), placeholder);
18	}
19
20	// revert to identity hashcode
21	public bool equals(O o) { ret this == o; }
22	public int hashCode() { ret systemHashCode(this); }
23	}