# A table is like an array, except that its keys are not integers but
# arbitrary types.
scenario table-read-write [
run [
1:address:table:number:number <- new-table 30
put 1:address:table:number:number, 12, 34
2:number <- index 1:address:table:number:number, 12
]
memory-should-contain [
2 <- 34
]
]
scenario table-read-write-non-integer [
run [
1:address:array:character <- new [abc def]
{2: (address table (address array character) number)} <- new-table 30
put {2: (address table (address array character) number)}, 1:address:array:character, 34
3:number <- index {2: (address table (address array character) number)}, 1:address:array:character
]
memory-should-contain [
3 <- 34
]
]
container table:_key:_value [
length:number
capacity:number
data:address:array:table_row:_key:_value
]
container table_row:_key:_value [
occupied?:boolean
key:_key
value:_value
]
def new-table capacity:number -> result:address:table:_key:_value [
local-scope
load-ingredients
result <- new {(table _key _value): type}
data:address:array:table_row:_key:_value <- new {(table_row _key _value): type}, capacity
*result <- merge 0/length, capacity, data
]
def put table:address:table:_key:_value, key:_key, value:_value -> table:address:table:_key:_value [
local-scope
load-ingredients
hash:number <- hash key
hash <- abs hash
capacity:number <- get *table, capacity:offset
_, hash <- divide-with-remainder hash, capacity
hash <- abs hash # in case hash overflows into a negative integer
table-data:address:array:table_row:_key:_value <- get *table, data:offset
x:table_row:_key:_value <- index *table-data, hash
occupied?:boolean <- get x, occupied?:offset
not-occupied?:boolean <- not occupied?:boolean
assert not-occupied?, [can't handle collisions yet]
new-row:table_row:_key:_value <- merge 1/true, key, value
*table-data <- put-index *table-data, hash, new-row
]
def abs n:number -> result:number [
local-scope
load-ingredients
positive?:boolean <- greater-or-equal n, 0
return-if positive?, n
result <- multiply n, -1
]
def index table:address:table:_key:_value, key:_key -> result:_value [
local-scope
load-ingredients
hash:number <- hash key
hash <- abs hash
capacity:number <- get *table, capacity:offset
_, hash <- divide-with-remainder hash, capacity
hash <- abs hash # in case hash overflows into a negative integer
table-data:address:array:table_row:_key:_value <- get *table, data:offset
x:table_row:_key:_value <- index *table-data, hash
occupied?:boolean <- get x, occupied?:offset
assert occupied?, [can't handle missing elements yet]
result <- get x, value:offset
]