insertWithKey

Insert with a combining function. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert f key new_value old_value.

let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value
insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")]
insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")]
insertWithKey f 5 "xxx" empty                         == singleton 5 "xxx"

Also see the performance note on fromListWith.

Insert with a combining function. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert f key new_value old_value.

let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value
insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")]
insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")]
insertWithKey f 5 "xxx" empty                         == singleton 5 "xxx"

If the key exists in the map, this function is lazy in value but strict in the result of f. Also see the performance note on fromListWith.

Insert with a function, combining key, new value and old value. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert the pair (key,f key new_value old_value). Note that the key passed to f is the same key passed to insertWithKey.

let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value
insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")]
insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")]
insertWithKey f 5 "xxx" empty                         == singleton 5 "xxx"

Also see the performance note on fromListWith.

Insert with a combining function. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert f key new_value old_value.

let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value
insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")]
insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")]
insertWithKey f 5 "xxx" empty                         == singleton 5 "xxx"

Insert with a combining function. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert f key new_value old_value.

let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value
insertWithKey f 5 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "5:xxx|a")]
insertWithKey f 7 "xxx" (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a"), (7, "xxx")]
insertWithKey f 5 "xxx" empty                         == singleton 5 "xxx"

If the key exists in the map, this function is lazy in value but strict in the result of f.

Insert a key-value pair into a map. Inserts the value directly if the key does not exist in the map. Otherwise, apply a supplied function that accepts the key, the new value, and the previous value and insert that result into the map.

O(log n). Insert with a function, combining key, new value and old value. insertWithKey f key value mp will insert the entry key :=> value into mp if key does not exist in the map. If the key does exist, the function will insert the entry key :=> f key new_value old_value. Note that the key passed to f is the same key passed to insertWithKey.

A variant of insertWith which also provides the key to the combining function.

O(log n) Insert a binding with a combining function.

Insert with a combining function. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert f key new_value old_value.

O(log n). Insert with a function, combining key, new value and old value. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert the pair (key,f key new_value old_value). Note that the key passed to f is the same key passed to insertWithKey. See insertMapWithKey for a version where the first argument is a IntMap.

let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value
insertWithKey f 5 "xxx" (fromList ((5,"a") :| [(3,"b")])) == fromList ((3, "b") :| [(5, "5:xxx|a")])
insertWithKey f 7 "xxx" (fromList ((5,"a") :| [(3,"b")])) == fromList ((3, "b") :| [(5, "a"), (7, "xxx")])

O(log n). Insert with a function, combining key, new value and old value. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert the pair (key,f key new_value old_value). Note that the key passed to f is the same key passed to insertWithKey. See insertMapWithKey for a version where the first argument is a Map.

let f key new_value old_value = (show key) ++ ":" ++ new_value ++ "|" ++ old_value
insertWithKey f 5 "xxx" (fromList ((5,"a") :| [(3,"b")])) == fromList ((3, "b") :| [(5, "5:xxx|a")])
insertWithKey f 7 "xxx" (fromList ((5,"a") :| [(3,"b")])) == fromList ((3, "b") :| [(5, "a"), (7, "xxx")])

O(log n). Insert with a function, combining key, new value and old value. insertWithKey f key value mp will insert the pair (key, value) into mp if key does not exist in the map. If the key does exist, the function will insert the pair (key, f key new_value old_value). Note that the key passed to f is the same key passed to insertWithKey.

RM.get (RM.insertWithKey (applyFun3 f) k v m) === M.insertWithKey (applyFun3 f) k v (RM.get m)

Insert a key-value pair into the map to obtain a potentially larger map, guaranteed to contain the given key. Like insertWith, but the combining function has access to the key, which is guaranteed to be in the old map.

Insert a key-value pair into the map to obtain a potentially larger map, guaranteed to contain the given key. Like insertWith, but the combining function has access to the key, which is guaranteed to be in the old map.

Insert a key-value pair into the map to obtain a potentially larger map, guaranteed to contain the given key. Like insertWith, but the combining function has access to the key, which is guaranteed to be in the old map.

Same as insertWithKey, but the combining function is applied strictly.

A variant of insertWithKey which applies the combining function strictly.

This function is being removed and is no longer usable. Use insertWithKey.