2778 - fix all layers

1 files changed, 86 insertions, 0 deletions

diff --git a/079table.mu b/079table.mu
new file mode 100644
index 00000000..56b7c9fd
--- /dev/null
+++ b/079table.mu
@@ -0,0 +1,86 @@
+# A table is like an array, except that its keys are not integers but
+# arbitrary types.
+
+scenario table-read-write [
+  run [
+    1:address:shared:table:number:number <- new-table 30
+    put 1:address:shared:table:number:number, 12, 34
+    2:number <- index 1:address:shared:table:number:number, 12
+  ]
+  memory-should-contain [
+    2 <- 34
+  ]
+]
+
+scenario table-read-write-non-integer [
+  run [
+    1:address:shared:array:character <- new [abc def]
+    {2: (address shared table (address shared array character) number)} <- new-table 30
+    put {2: (address shared table (address shared array character) number)}, 1:address:shared:array:character, 34
+    3:number <- index {2: (address shared table (address shared array character) number)}, 1:address:shared:array:character
+  ]
+  memory-should-contain [
+    3 <- 34
+  ]
+]
+
+container table:_key:_value [
+  length:number
+  capacity:number
+  data:address:shared:array:table_row:_key:_value
+]
+
+container table_row:_key:_value [
+  occupied?:boolean
+  key:_key
+  value:_value
+]
+
+def new-table capacity:number -> result:address:shared:table:_key:_value [
+  local-scope
+  load-ingredients
+  result <- new {(table _key _value): type}
+  tmp:address:number <- get-address *result, capacity:offset
+  *tmp <- copy capacity
+  data:address:address:shared:array:table_row:_key:_value <- get-address *result, data:offset
+  *data <- new {(table_row _key _value): type}, capacity
+]
+
+def put table:address:shared:table:_key:_value, key:_key, value:_value -> table:address:shared: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:shared:array:table_row:_key:_value <- get *table, data:offset
+  x:address:table_row:_key:_value <- index-address *table-data, hash
+  occupied?:boolean <- get *x, occupied?:offset
+  not-occupied?:boolean <- not occupied?:boolean
+  assert not-occupied?, [can't handle collisions yet]
+  *x <- merge 1/true, key, value
+]
+
+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:shared: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:shared: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
+]