- Associative arrays are declared by placing the key type within - the [] of an array declaration: + Associative arrays are declared by placing the KeyType + within the [] of an array declaration:
int[char[]] b; // associative array b of ints that are - // indexed by an array of characters + // indexed by an array of characters. + // The KeyType is char[] b["hello"] = 3; // set value associated with key "hello" to 3 func(b["hello"]); // pass 3 as parameter to func()@@ -848,7 +849,7 @@ delete operator:
- delete b["hello"]; + delete b["hello"];This confusingly appears to delete the value of b["hello"], but @@ -856,15 +857,50 @@
The InExpression yields a pointer to the value - if the key is in the associatve array, or null if not: + if the key is in the associative array, or null if not:
- if (("hello" in b) != null)
+ int* p;
+ p = ("hello" in b);
+ if (p != null)
...
- Key types cannot be functions or voids.
+ KeyTypes cannot be functions or voids.
+ + + If the KeyType is a struct type, a default mechanism is used + to compute the hash and comparisons of it based on the binary + data within the struct value. A custom mechanism can be used + by providing the following functions as struct members: + +
+ uint toHash(); + int opCmp(KeyType* s); ++ + For example: +
+ import std.string;
+
+ struct MyString
+ {
+ char[] str;
+
+ uint toHash()
+ { uint hash;
+ foreach (char c; s)
+ hash = (hash * 9) + c;
+ return hash;
+ }
+
+ int opCmp(MyString* s)
+ {
+ return std.string.cmp(this.str, s.str);
+ }
+ }
+
| size + | .size | Returns the size of the reference to the associative array; it is typically 8. |
| length + | .length | Returns number of values in the associative array. Unlike for dynamic arrays, it is read-only. |
| keys + | .keys | Returns dynamic array, the elements of which are the keys in the associative array. |
| values + | .values | Returns dynamic array, the elements of which are the values in the associative array. |
| rehash + | .rehash | Reorganizes the associative array in place so that lookups
are more efficient. rehash is effective when, for example,
the program is done loading up a symbol table and now needs
diff -uNr dmd-0.109/dmd/html/d/changelog.html dmd-0.110/dmd/html/d/changelog.html
--- dmd-0.109/dmd/html/d/changelog.html 2004-12-05 01:16:42.000000000 +0100
+++ dmd-0.110/dmd/html/d/changelog.html 2004-12-30 14:59:16.000000000 +0100
@@ -24,6 +24,7 @@
+ + What's New for + D 0.110 ++ +Dec 30, 2004 + +New/Changed Features+
Bugs Fixed+
What's New for
D 0.109
diff -uNr dmd-0.109/dmd/html/d/intro.html dmd-0.110/dmd/html/d/intro.html
--- dmd-0.109/dmd/html/d/intro.html 2004-09-01 11:40:04.000000000 +0200
+++ dmd-0.110/dmd/html/d/intro.html 2004-12-14 10:36:34.000000000 +0100
@@ -14,7 +14,7 @@
[Home]
[Search]
[D]
- |