Mu - 064list.mu

# A list links up multiple objects together to make them easier to manage.
#
# The objects must be of the same type. If you want to store multiple types in
# a single list, use an exclusive-container.

container list:_elem [
  value:_elem
  next:&:list:_elem
]

def push x:_elem, l:&:list:_elem -> l:&:list:_elem [
  local-scope
  load-ingredients
  result:&:list:_elem <- new {(list _elem): type}
  *result <- merge x, l
  reply result
]

def first in:&:list:_elem -> result:_elem [
  local-scope
  load-ingredients
  result <- get *in, value:offset
]

def rest in:&:list:_elem -> result:&:list:_elem/contained-in:in [
  local-scope
  load-ingredients
  result <- get *in, next:offset
]

scenario list-handling [
  run [
    local-scope
    x:&:list:num <- push 3, 0
    x <- push 4, x
    x <- push 5, x
    10:num/raw <- first x
    x <- rest x
    11:num/raw <- first x
    x <- rest x
    12:num/raw <- first x
    20:&:list:num/raw <- rest x
  ]
  memory-should-contain [
    10 <- 5
    11 <- 4
    12 <- 3
    20 <- 0  <.calva/output-window/
.classpath
.clj-kondo/.cache
.cpcache
.DS_Store
.eastwood
.factorypath
.hg/
.hgignore
.java-version
.lein-*
.lsp/.cache
.lsp/sqlite.db
.nrepl-history
.nrepl-port
.portal
.project
.rebel_readline_history
.settings
.socket-repl-port
.sw*
.vscode
*.class
*.jar
*.swp
*~
/checkouts
/classes
/target

/span>:char/raw <- first list2 list2 <- rest list2 12:char/raw <- first list2 list2 <- rest list2 13:char/raw <- first list2 ] memory-should-contain [ 10 <- 5 # scanning next 11 <- 6 # inserted element 12 <- 4 13 <- 3 ] ] # remove 'x' from its surrounding list 'in' # # Returns null if and only if list is empty. Beware: in that case any other # pointers to the head are now invalid. def remove x:&:list:_elem/contained-in:in, in:&:list:_elem -> in:&:list:_elem [ local-scope load-ingredients # if 'x' is null, return return-unless x next-node:&:list:_elem <- rest x # clear next pointer of 'x' *x <- put *x, next:offset, 0 # if 'x' is at the head of 'in', return the new head at-head?:bool <- equal x, in return-if at-head?, next-node # compute prev-node prev-node:&:list:_elem <- copy in curr:&:list:_elem <- rest prev-node { return-unless curr found?:bool <- equal curr, x break-if found? prev-node <- copy curr curr <- rest curr } # set its next pointer to skip 'x' *prev-node <- put *prev-node, next:offset, next-node ] scenario removing-from-list [ local-scope list:&:list:char <- push 3, 0 list <- push 4, list list <- push 5, list run [ list2:&:list:char <- rest list # second element list <- remove list2, list 10:bool/raw <- equal list2, 0 # check structure like before list2 <- copy list 11:char/raw <- first list2 list2 <- rest list2 12:char/raw <- first list2 20:&:list:char/raw <- rest list2 ] memory-should-contain [ 10 <- 0 # remove returned non-null 11 <- 5 # scanning next, skipping deleted element 12 <- 3 20 <- 0 # no more elements ] ] scenario removing-from-start-of-list [ local-scope list:&:list:char <- push 3, 0 list <- push 4, list list <- push 5, list run [ list <- remove list, list # check structure like before list2:&:list:char <- copy list 10:char/raw <- first list2 list2 <- rest list2 11:char/raw <- first list2 20:&:list:char/raw <- rest list2 ] memory-should-contain [ 10 <- 4 # scanning next, skipping deleted element 11 <- 3 20 <- 0 # no more elements ] ] scenario removing-from-end-of-list [ local-scope list:&:list:char <- push 3, 0 list <- push 4, list list <- push 5, list run [ # delete last element list2:&:list:char <- rest list list2 <- rest list2 list <- remove list2, list 10:bool/raw <- equal list2, 0 # check structure like before list2 <- copy list 11:char/raw <- first list2 list2 <- rest list2 12:char/raw <- first list2 20:&:list:char/raw <- rest list2 ] memory-should-contain [ 10 <- 0 # remove returned non-null 11 <- 5 # scanning next, skipping deleted element 12 <- 4 20 <- 0 # no more elements ] ] scenario removing-from-singleton-list [ local-scope list:&:list:char <- push 3, 0 run [ list <- remove list, list 1:num/raw <- copy list ] memory-should-contain [ 1 <- 0 # back to an empty list ] ] # reverse the elements of a list # (contributed by Caleb Couch) def reverse list:&:list:_elem temp:&:list:_elem/contained-in:result -> result:&:list:_elem [ local-scope load-ingredients reply-unless list, temp object:_elem <- first, list list <- rest list temp <- push object, temp result <- reverse list, temp ] scenario reverse-list [ local-scope list:&:list:number <- push 1, 0 list <- push 2, list list <- push 3, list run [ stash [list:], list list <- reverse list stash [reversed:], list ] trace-should-contain [ app: list: 3 -> 2 -> 1 app: reversed: 1 -> 2 -> 3 ] ] def to-text in:&:list:_elem -> result:text [ local-scope load-ingredients buf:&:buffer <- new-buffer 80 buf <- to-buffer in, buf result <- buffer-to-array buf ] # variant of 'to-text' which stops printing after a few elements (and so is robust to cycles) def to-text-line in:&:list:_elem -> result:text [ local-scope load-ingredients buf:&:buffer <- new-buffer 80 buf <- to-buffer in, buf, 6 # max elements to display result <- buffer-to-array buf ] def to-buffer in:&:list:_elem, buf:&:buffer -> buf:&:buffer [ local-scope load-ingredients { break-if in buf <- append buf, [[]] return } # append in.value to buf val:_elem <- get *in, value:offset buf <- append buf, val # now prepare next next:&:list:_elem <- rest in nextn:num <- copy next return-unless next buf <- append buf, [ -> ] # and recurse remaining:num, optional-ingredient-found?:bool <- next-ingredient { break-if optional-ingredient-found? # unlimited recursion buf <- to-buffer next, buf return } { break-unless remaining # limited recursion remaining <- subtract remaining, 1 buf <- to-buffer next, buf, remaining return } # past recursion depth; insert ellipses and stop append buf, [...] ] scenario stash-empty-list [ local-scope x:&:list:num <- copy 0 run [ stash x ] trace-should-contain [ app: [] ] ]