diff options
Diffstat (limited to 'lisp/align.el')
| -rw-r--r-- | lisp/align.el | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/lisp/align.el b/lisp/align.el index 1b62042be75..3d2ca192245 100644 --- a/lisp/align.el +++ b/lisp/align.el @@ -906,15 +906,8 @@ on the format of these lists." ;;;###autoload (defun align-regexp (beg end regexp &optional group spacing repeat) "Align the current region using an ad-hoc rule read from the minibuffer. -BEG and END mark the limits of the region. This function will prompt -for the REGEXP to align with. If no prefix arg was specified, you -only need to supply the characters to be lined up and any preceding -whitespace is replaced. If a prefix arg was specified, the full -regexp with parenthesized whitespace should be supplied; it will also -prompt for which parenthesis GROUP within REGEXP to modify, the amount -of SPACING to use, and whether or not to REPEAT the rule throughout -the line. See `align-rules-list' for more information about these -options. +BEG and END mark the limits of the region. Interactively, this function +prompts for the regular expression REGEXP to align with. For example, let's say you had a list of phone numbers, and wanted to align them so that the opening parentheses would line up: @@ -925,8 +918,29 @@ align them so that the opening parentheses would line up: Joe (123) 456-7890 There is no predefined rule to handle this, but you could easily do it -using a REGEXP like \"(\". All you would have to do is to mark the -region, call `align-regexp' and type in that regular expression." +using a REGEXP like \"(\". Interactively, all you would have to do is +to mark the region, call `align-regexp' and enter that regular expression. + +REGEXP must contain at least one parenthesized subexpression, typically +whitespace of the form \"\\\\(\\\\s-*\\\\)\". In normal interactive use, +this is automatically added to the start of your regular expression after +you enter it. You only need to supply the characters to be lined up, and +any preceding whitespace is replaced. + +If you specify a prefix argument (or use this function non-interactively), +you must enter the full regular expression, including the subexpression. +The function also then prompts for which subexpression parenthesis GROUP +\(default 1) within REGEXP to modify, the amount of SPACING (default +`align-default-spacing') to use, and whether or not to REPEAT the rule +throughout the line. + +See `align-rules-list' for more information about these options. + +The non-interactive form of the previous example would look something like: + \(align-regexp (point-min) (point-max) \"\\\\(\\\\s-*\\\\)(\") + +This function is a nothing more than a small wrapper that helps you +construct a rule to pass to `align-region', which does the real work." (interactive (append (list (region-beginning) (region-end)) @@ -1498,6 +1512,9 @@ aligner would have dealt with are." (setq rule-beg (match-beginning first) save-match-data (match-data)) + (or rule-beg + (error "No match for subexpression %s" first)) + ;; unless the `valid' attribute is set, and tells ;; us that the rule is not valid at this point in ;; the code.. |