Vimscript Functions: `filecopy()`, `filereadable()`, `filewritable()`, and `filter()`

executing commands, thus calling it recursively, then all typeahead will be consumed by the last call. '!' When used with 'x' will not end Insert mode. Can be used in a test when a timer is set to exit Insert mode a little later. Useful for testing CursorHoldI. Return value is always 0. Parameters: ~ • {string} (`string`) • {mode} (`string?`) Return: ~ (`any`) filecopy({from}, {to}) *filecopy()* Copy the file pointed to by the name {from} to {to}. The result is a Number, which is |TRUE| if the file was copied successfully, and |FALSE| when it failed. If a file with name {to} already exists, it will fail. Note that it does not handle directories (yet). This function is not available in the |sandbox|. Parameters: ~ • {from} (`string`) • {to} (`string`) Return: ~ (`0|1`) filereadable({file}) *filereadable()* The result is a Number, which is |TRUE| when a file with the name {file} exists, and can be read. If {file} doesn't exist, or is a directory, the result is |FALSE|. {file} is any expression, which is used as a String. If you don't care about the file being readable you can use |glob()|. {file} is used as-is, you may want to expand wildcards first: >vim echo filereadable('~/.vimrc') < > 0 < >vim echo filereadable(expand('~/.vimrc')) < > 1 < Parameters: ~ • {file} (`string`) Return: ~ (`0|1`) filewritable({file}) *filewritable()* The result is a Number, which is 1 when a file with the name {file} exists, and can be written. If {file} doesn't exist, or is not writable, the result is 0. If {file} is a directory, and we can write to it, the result is 2. Parameters: ~ • {file} (`string`) Return: ~ (`0|1`) filter({expr1}, {expr2}) *filter()* {expr1} must be a |List|, |String|, |Blob| or |Dictionary|. For each item in {expr1} evaluate {expr2} and when the result is zero or false remove the item from the |List| or |Dictionary|. Similarly for each byte in a |Blob| and each character in a |String|. {expr2} must be a |string| or |Funcref|. If {expr2} is a |string|, inside {expr2} |v:val| has the value of the current item. For a |Dictionary| |v:key| has the key of the current item and for a |List| |v:key| has the index of the current item. For a |Blob| |v:key| has the index of the current byte. For a |String| |v:key| has the index of the current character. Examples: >vim call filter(mylist, 'v:val !~ "OLD"') < Removes the items where "OLD" appears. >vim call 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

This section details the `filecopy()`, `filereadable()`, `filewritable()`, and `filter()` functions in Vimscript. `filecopy()` copies a file, failing if the destination exists and not handling directories. `filereadable()` checks if a file exists and is readable. `filewritable()` checks if a file exists and is writable, returning 2 if it's a writable directory. `filter()` removes items from a List, String, Blob, or Dictionary based on a condition specified by a string or Funcref expression.