Breaking up (melting) text data in a column in R? -

i have csv file contains data in following format:

prjid, objective
1001 , (i) improve efficiency (ii) decrease cost (iii) maximize revenue
1002 , a) have fun b) learn new things
1003 , (1) getting tricky (2) challanging task

first variable id , second variable text variable "objective". each project has data on multiple objectives in single column seperate (i), (ii), ..etc or (a), (b), (c),..etc, or (1), (2), (3), ..etc. want observation created each objective of projects. this:

prjid, objective
1001 , (i) improve efficiency
1001 , (ii) decrease cost
1001 , (iii) maximize revenue
1002 , a) have fun
1002 , b) learn new things
1003 , (1) getting tricky
1003 , (2) challanging task

for projects have 1 objective, has 1 row. multiple objectives splits observation.

i quite new handling text data in r, can r pro me started problem? in advance!

here 1 idea.

1. insert new delimiter in objective column, using clever regular expression
2. use delimiter within strsplit split sentence in vector
3. using by , process previous steps id.

following steps , code:

ll <- by(dat,dat$prjid,fun = function(x){         x.delim <- gsub(" (\\(?[a-x,0-9]*\\))",'#\\1',x$objective)         obj  = unlist(strsplit(x.delim,'#'))         data.frame(prjid= x$prjid,objective=obj[-1]) }) ## transform list data.frame do.call(rbind,ll)        prjid                 objective 1001.1  1001 (i) improve efficiency 1001.2  1001        (ii) decrease cost 1001.3  1001   (iii) maximize revenue  1002.1  1002               a) have fun 1002.2  1002      b) learn new things  1003.1  1003        (1) getting tricky 1003.2  1003      (2) challanging task 

ps , here dat :

dat <- read.table(text='prjid, objective  1001 , (i) improve efficiency (ii) decrease cost (iii) maximize revenue  1002 , a) have fun b) learn new things  1003 , (1) getting tricky (2) challanging task',sep=',',header=true)