How to use VI to remove ocurance of character on lines matching regex?

Question

I'm trying to change the case of method names for some functions from lowercase_with_underscores to lowerCamelCase for lines that begin with public function get_method_name(). I'm struggling to get this done in a single step.

So far I have used the following

:%s/\(get\)\([a-zA-Z]*\)_\(\w\)/\1\2\u\3/g

However, this only replaces one _ character at a time. What I would like it a search and replace that does something like the following:

1. Identify all lines containing the string public function [gs]et.
2. On these lines, perform the following search and replace :s/_\(\w\)/\u\1/g (

EDIT:

Suppose I have lines get_method_name() and set_method_name($variable_name) and I only want to change the case of the method name and not the variable name, how might I do that? The get_method_name() is more simple of course, but I'd like a solution that works for both in a single command. I've been able to use :%g/public function [gs]et/ . . . as per the solution listed below to solve for the get_method_name() case, but unfortunately not the set_method_name($variable_name) case.

Answer 1

If I've understood you correctly, I don't know why the things you've tried haven't worked but you can use g to perform a normal mode command on lines matchings a pattern.

Your example would be something like:

:%g/public function [gs]et/:s/_\(\w\)/\u\1/g

Update:

To match only the method names, we can use the fact that there will only be method names before the first $, as this looks to be PHP.

To do that, we can use a negative lookbehind, @<!:

:%g/public function [gs]et/:s/\(\$.\+\)\@<!_\(\w\)/\u\2/g

This will look behind @<! for any $ followed by any number of characters and only match _\(\w\) if no $s are found.

Bonus points(?):

To do this for multiple buffers stick a bufdo in front of the %g

Answer 2

To have vi do replace sad with happy, on all lines, in a file:

:1, $ s/sad/happy/g

(It is the :1, $ before the sed command that instructs vi to execute the command on every line in the file.)

Answer 3

You want to use a substitute with an expression (:h sub-replace-expression)

Match the complete string you want to process then pass that string to a second substitute command to actually change the string

:%s/\(get\|set\)\zs_\w\+/\=substitute(submatch(0), '_\([A-Za-z]\)', '\U\1', 'g')

Running the above on

get_method_name($variable_name)
set_method_name($variable_name)

returns

getMethodName($variable_name)
setMethodName($variable_name)