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RE: split-string description in the ELR
From: |
Drew Adams |
Subject: |
RE: split-string description in the ELR |
Date: |
Mon, 1 May 2017 09:20:45 -0700 (PDT) |
> Without Eli's comment I would never have thought of using split-string to
> trim a string. But even reading the reference did not make it's use super
> clear. In the description "trim" is just an option to trim the substrings
> resulting from splitting the string and it is not obvious that it can be
> used on it's own to trim a given string.
>
> Could a small modification of the reference be in order to emphasize that
> use (with an example eventually) ?
Good idea. Additionally, or instead, we could create a function
that is an alias and that has "trim" in the name.
----
FWIW, I define function `split-string-by-regexp' to do just
what vanilla `split-string' does, and I redefine `split-string'
to handle additional ways to specify the splitting. The
redefined function does `split-string-by-regexp' by default.
Here are the signature and doc string of the redefined `split-string':
(split-string STRING &optional HOW OMIT-NULLS TRIM FLIP TEST)
Split STRING into substrings.
Arg HOW determines how splitting is done. it is one of the following:
* a regexp (a string) - see function `split-string-by-regexp'
* a list whose first element is a text property (a symbol) and whose
second element is the property value - see function
`split-string-by-property'
* a predicate that accepts a character as its first argument - see
function `split-string-by-predicate'
If optional arg OMIT-NULLS is t, then empty substrings are omitted
from the returned list. If nil, zero-length substrings are retained,
which correctly parses CSV format, for example.
If TRIM is non-nil, it should be a regular expression to match text to
trim from the beginning and end of each substring. If trimming makes
a substring empty, it is treated according to OMIT-NULLS.
Optional arg TEST is used only if HOW is a (PROPERTY VALUE) list, in
which case it is passed to function `split-string-by-property' (which
see). Otherwise, it is ignored.
Modifies the match data; use `save-match-data' if necessary.
Each of the HOW possibilities corresponds also to a separate
function:
split-string-by-regexp
split-string-by-property
split-string-by-predicate
https://www.emacswiki.org/emacs/download/subr%2b.el