mirror of
https://github.com/HigherOrderCO/Bend.git
synced 2024-10-26 14:05:36 +03:00
e44f68ba8c
occurence -> occurrence
173 lines
3.8 KiB
Plaintext
173 lines
3.8 KiB
Plaintext
##############################
|
|
# Author: Ematth, 2024
|
|
##############################
|
|
### Singly-Linked List Type Definition: ###
|
|
|
|
# The List type is builtin, so we don't need to declare it.
|
|
# But this is how it's defined in the builtins file.
|
|
# type List:
|
|
# Nil
|
|
# Cons { head, ~tail }
|
|
|
|
###########################################
|
|
|
|
# List clear:
|
|
# List l -> list l
|
|
# clears all elements from list l. This is equivalent to initializing an empty list.
|
|
clear = @l []
|
|
|
|
# List concat:
|
|
# List l -> List l
|
|
# combines two lists (l1, l2) from left to right.
|
|
concat = @l1 @l2
|
|
match l1 {
|
|
List/Cons: (List/Cons l1.head (concat l1.tail l2))
|
|
List/Nil: l2
|
|
}
|
|
|
|
# List add_front:
|
|
# List l -> List l
|
|
# adds a non-List element e to the front of list l.
|
|
add_front = @l @e
|
|
match l {
|
|
List/Cons: (List/Cons e l)
|
|
List/Nil: (List/Cons e List/Nil)
|
|
}
|
|
|
|
# List append (add_back):
|
|
# List l -> List l
|
|
# adds a non-list element e to the back of list l.
|
|
append = @l @e
|
|
(concat l (List/Cons e List/Nil))
|
|
|
|
# list sum:
|
|
# List l -> uint
|
|
# returns the sum of all items in the list.
|
|
sum = @l
|
|
match l {
|
|
List/Cons: (+ l.head (sum l.tail))
|
|
List/Nil: 0
|
|
}
|
|
|
|
# List reverse:
|
|
# List l -> List l
|
|
# reverses the order of elements in list l.
|
|
reverse.aux = @acc @l
|
|
match l {
|
|
List/Nil: acc
|
|
List/Cons: (reverse.aux (List/Cons l.head acc) l.tail)
|
|
}
|
|
reverse = @l
|
|
(reverse.aux [] l)
|
|
|
|
# List length:
|
|
# List l -> uint
|
|
# returns the number of elements in list l.
|
|
len = @l
|
|
match l {
|
|
List/Nil: 0
|
|
List/Cons: (+ 1 (len l.tail))
|
|
}
|
|
|
|
# List count:
|
|
# List l -> uint -> uint
|
|
# returns the number of instances of Some s in list l.
|
|
count.aux = @acc @l @s
|
|
match l {
|
|
List/Nil: acc
|
|
List/Cons: use acc = switch (== l.head s) {
|
|
0: acc;
|
|
_: (+ acc 1);
|
|
}
|
|
(count.aux acc l.tail s)
|
|
}
|
|
count = @l @s
|
|
(count.aux 0 l s)
|
|
|
|
# List index:
|
|
# List l -> Some s
|
|
# returns the value of a specific list index i, or * if the index doesn't exist.
|
|
index = @l @i
|
|
match l {
|
|
List/Cons:
|
|
switch i {
|
|
0: l.head
|
|
_: (index l.tail (i-1))
|
|
}
|
|
List/Nil: *
|
|
}
|
|
|
|
# List head:
|
|
# List l -> Some s
|
|
# returns the first item in the list, or [] if the list is empty.
|
|
head = @l
|
|
match l {
|
|
List/Cons: l.head
|
|
List/Nil: []
|
|
}
|
|
|
|
# List pop_front:
|
|
# List l -> List l
|
|
# removes and discards the first item of list l.
|
|
# The new list is returned, or [] if the list is empty.
|
|
pop_front = @l
|
|
match l {
|
|
List/Cons: l.tail
|
|
List/Nil: []
|
|
}
|
|
|
|
# List pop_back:
|
|
# List l -> List l
|
|
# removes and discards the the last item of list l.
|
|
pop_back (List/Nil) = List/Nil
|
|
pop_back (List/Cons x List/Nil) = List/Nil
|
|
pop_back (List/Cons head tail) = (List/Cons head (pop_back tail))
|
|
|
|
# List remove:
|
|
# List l -> Some s -> List l
|
|
# removes the first occurrence of element e from list l.
|
|
remove = @l @s
|
|
match l {
|
|
List/Cons:
|
|
switch (== l.head s) {
|
|
0: (List/Cons l.head (remove l.tail s))
|
|
_: l.tail
|
|
}
|
|
List/Nil: List/Nil
|
|
}
|
|
|
|
# List split:
|
|
# list l -> uint i -> (List l, list l)
|
|
# splits list l into two lists (l1, l2) at index i.
|
|
# the second list takes the element at index i during the split.
|
|
split = @l @i (split.aux [] l i)
|
|
|
|
split.aux = @acc @l @i
|
|
match l {
|
|
List/Cons:
|
|
switch i {
|
|
0: (acc, l)
|
|
_: (split.aux (append acc l.head) l.tail i-1)
|
|
}
|
|
List/Nil: *
|
|
}
|
|
|
|
|
|
#################################
|
|
|
|
def main:
|
|
return head([5, 4, 3, 2, 1])
|
|
# return sum([1, 2, 3])
|
|
# return split([1, 2, 3, 4, 5, 6, 7], 3)
|
|
# return remove([1, 2, 1, 3], 1)
|
|
# return pop_back([1, 2, 3, 4])
|
|
# return pop_front([1, 2, 3])
|
|
# return index([5, 3, 6, 8, 2], 0)
|
|
# return clear([0, 2, 3])
|
|
# return count([1, 2, 3, 3, 3, 4, 4, 5, 3, 1000], 4)
|
|
# return len([1, 2, 3, 4, 4, 4])
|
|
# return reverse([1, 2, 3, 4, 5])
|
|
# return append([1, 2], 3)
|
|
# return add_front([2, 3], 1)
|
|
# return concat([1, 2], [3, 4])
|