Technically, picrin's array is implemented as a ring-buffer, effective double-ended queue data structure (deque) that can operate pushing and poping from both of front and back in constant time. In addition to the deque interface, array provides standard sequence interface similar to functions specified by R7RS.
-**(make-array [capacity])**
Returns a newly allocated array object. If capacity is given, internal data chunk of the array object will be initialized by capacity size.
-**(array . objs)**
Returns an array initialized with objs.
-**(array? . obj)**
Returns #t if obj is an array.
-**(array-length ary)**
Returns the length of ary.
-**(array-ref ary i)**
Like ``list-ref``, return the object pointed by the index i.
-**(array-set! ary i obj)**
Like ``list-set!``, substitutes the object pointed by the index i with given obj.
-**(array-push! ary obj)**
Adds obj to the end of ary.
-**(array-pop! ary)**
Removes the last element of ary, and returns it.
-**(array-unshift! ary obj)**
Adds obj to the front of ary.
-**(array-shift! ary)**
Removes the first element of ary, and returns it.
-**(array-map proc ary)**
Performs mapping operation on ary.
-**(array-for-each proc ary)**
Performs mapping operation on ary, but discards the result.
Note that dictionary is not a weak map; if you are going to make a highly memory-consuming program with dictionaries, you should know that dictionaries keep their bound objects and never let them free until you explicitly deletes bindings.
Look up dictionary dict for a value associated with key. It returns two values: first is the associated value if exists, and second is a boolean of lookup result.
If there is no value already associated with key, this function newly creates a binding of key with obj. Otherwise, updates the existing binding with given obj.
