R - Grepl vector over vector

Question

I have a vector of character strings (v1) like so:

> head(v1)
[1] "do_i_need_to_even_say_it_do_i_well_here_i_go_anyways_chris_cornell_in_chicago_tonight"                                       
[2] "going_to_see_harry_sunday_happiness"                                                                                         
[3] "this_motha_fucka_stay_solid_foh_with_your_naieve_ass_mentality_your_synapsis_are_lacking_read_a_fucking_book_for_christ_sake"
[4] "why_twitter_will_soon_become_obsolete_http_www.imediaconnection.com_content_23465_asp"                                       
[5] "like_i_said_my_back_still_fucking_hurts_and_im_going_to_complain_about_it_like_no_ones_business_http_tumblr.com_x6n25amd5"   
[6] "my_picture_with_kris_karmada_is_gone_forever_its_not_in_my_comments_on_my_mysapce_or_on_my_http_tumblr.com_xzg1wy4jj"

And another vector of character strings (v2) like so:

> head(v2)
[1] "here_i_go" "going" "naieve_ass" "your_synapsis"   "my_picture_with"   "roll" 

What is the quickest way that I can return a list of vectors where each list item represents each vector item in v1 and each vector item is a regular expression match where an item in v2 appeared in that v1 item, like so:

[[1]]
[1] "here_i_go"

[[2]]
[1] "going"

[[3]]
[1] "naieve_ass"      "your_synapsis"

[[4]]

[[5]]
[1] "going"

[[6]]
[1] "my_picture_with"

Answer 1

I'd like to leave another option with stri_extract_all_regex() in the stringi package. You can create your regular expression directly from v2 and use it in pattern.

library(stringi)

stri_extract_all_regex(str = v1, pattern = paste(v2, collapse = "|"))

[[1]]
[1] "here_i_go"

[[2]]
[1] "going"

[[3]]
[1] "naieve_ass"    "your_synapsis"

[[4]]
[1] NA

[[5]]
[1] "going"

[[6]]
[1] "my_picture_with"