Vimscript Functions: `filter()` (continued), `finddir()`, `findfile()`, `flatten()`, and `flattennew()`

filter(mydict, 'v:key >= 8') < Removes the items with a key below 8. >vim call filter(var, 0) < Removes all the items, thus clears the |List| or |Dictionary|. Note that {expr2} is the result of expression and is then used as an expression again. Often it is good to use a |literal-string| to avoid having to double backslashes. If {expr2} is a |Funcref| it must take two arguments: 1. the key or the index of the current item. 2. the value of the current item. The function must return |TRUE| if the item should be kept. Example that keeps the odd items of a list: >vim func Odd(idx, val) return a:idx % 2 == 1 endfunc call filter(mylist, function('Odd')) < It is shorter when using a |lambda|: >vim call filter(myList, {idx, val -> idx * val <= 42}) < If you do not use "val" you can leave it out: >vim call filter(myList, {idx -> idx % 2 == 1}) < For a |List| and a |Dictionary| the operation is done in-place. If you want it to remain unmodified make a copy first: >vim let l = filter(copy(mylist), 'v:val =~ "KEEP"') < Returns {expr1}, the |List| or |Dictionary| that was filtered, or a new |Blob| or |String|. When an error is encountered while evaluating {expr2} no further items in {expr1} are processed. When {expr2} is a Funcref errors inside a function are ignored, unless it was defined with the "abort" flag. Parameters: ~ • {expr1} (`string|table`) • {expr2} (`string|function`) Return: ~ (`any`) finddir({name} [, {path} [, {count}]]) *finddir()* Find directory {name} in {path}. Supports both downwards and upwards recursive directory searches. See |file-searching| for the syntax of {path}. Returns the path of the first found match. When the found directory is below the current directory a relative path is returned. Otherwise a full path is returned. If {path} is omitted or empty then 'path' is used. If the optional {count} is given, find {count}'s occurrence of {name} in {path} instead of the first one. When {count} is negative return all the matches in a |List|. Returns an empty string if the directory is not found. This is quite similar to the ex-command `:find`. Parameters: ~ • {name} (`string`) • {path} (`string?`) • {count} (`integer?`) Return: ~ (`string|string[]`) findfile({name} [, {path} [, {count}]]) *findfile()* Just like |finddir()|, but find a file instead of a directory. Uses 'suffixesadd'. Example: >vim echo findfile("tags.vim", ".;") < Searches from the directory of the current file upwards until it finds the file "tags.vim". Parameters: ~ • {name} (`string`) • {path} (`string?`) • {count} (`integer?`) Return: ~ (`string|string[]`) flatten({list} [, {maxdepth}]) *flatten()* Flatten {list} up to {maxdepth} levels. Without {maxdepth} the result is a |List| without nesting, as if {maxdepth} is a very large number. The {list} is changed in place, use |flattennew()| if you do not want that. *E900* {maxdepth} means how deep in nested lists changes are made. {list} is not modified when {maxdepth} is 0. {maxdepth} must be positive number. If there is an error the number zero is returned. Example: >vim echo flatten([1, [2, [3, 4]], 5]) < [1, 2, 3, 4, 5] >vim echo flatten([1, [2, [3, 4]], 5], 1) < [1, 2, [3, 4], 5] Parameters: ~ • {list} (`any[]`) • {maxdepth} (`integer?`) Return: ~ (`any[]|0`) flattennew({list} [, {maxdepth}]) *flattennew()* Like |flatten()| but first

This section continues the explanation of the `filter()` function, illustrating its in-place operation and return value, including scenarios with Funcrefs and errors. It then describes `finddir()`, which searches for a directory in a specified path, and `findfile()`, which does the same for a file. `flatten()` flattens a list up to a specified depth, modifying it in place, while `flattennew()` does the same but returns a new flattened list.