+ symbolFieldsCompletion <- function(object, rest) {
+ ## FIXME: this is hacky, ignoring several syntax issues (use of
+ ## and/or necessity for backquoting identifiers: e.g. fields
+ ## containing hyphens)
+ if((dollar <- regexpr("$", rest, fixed=TRUE)) == -1) {
+ matches <- grep(sprintf("^%s", literal2rx(rest)), names(object), value=TRUE)
+ matches <- sprintf("%s$%s", gsub("\\$[^$]*$", "", prefix), matches)
+ returnMatches(matches)
+ } else {
+ if(exists(substr(rest, 1, dollar-1), object)) {
+ symbolFieldsCompletion(get(substr(rest, 1, dollar-1), object), substr(rest, dollar+1, nchar(rest)))
+ } else {
+ returnMatches(character(0))
+ }
+ }
+ }
+ returnMatches <- function(matches) {
+ nmatches <- length(matches)
+ if(nmatches == 0) {
+ list(list(), "")
+ } else {
+ longest <- matches[order(nchar(matches))][1]
+ while(length(grep(sprintf("^%s", literal2rx(longest)), matches)) < nmatches) {
+ longest <- substr(longest, 1, nchar(longest)-1)
+ }
+ list(as.list(matches), longest)
+ }
+ }