An abstraction to make URLs from named R lists, rather than doing in-place string concatenation

makeURL.R

a <- list(id=242, 'session_id'='ah876fh3', main='page.html')

makeURL <-
# Given a named list of key/values, concatenate to make a URL. The
# value of the entry with key 'main' is treated as the HTML page.
function(pieces) {
  m <- which(names(pieces) == 'main')
  keys.values <- paste(names(pieces[-m]), pieces[-m], collapse='&', sep='=')
  return(paste(pieces[[m]], keys.values, sep='?'))
}

makeURL(a)