# bib-select.awk - emit entries selected by key, canonically
#
# Requires bib-parse.awk and bib-canon.awk. Variables (set with -v):
#   keys    - comma-separated list of entry keys; a key of "*" selects
#             every entry (as produced by \nocite{*})
#   keyfile - file with one key per line, for key lists too large to
#             pass on the command line; merged with keys
#   invert  - 0: emit entries whose key is in the list
#             1: emit entries whose key is NOT in the list
#
# With no keys and invert=1 this acts as a canonicalizing filter for
# everything. @string and @preamble blocks always pass through.

function bib_sel_add(k) {
  if (k == "*")
    BIB_SEL_ALL = 1
  else
    BIB_SEL[k] = 1
}

BEGIN {
  bib_sel_n = split(keys, bib_sel_k, ",")
  for (bib_sel_i = 1; bib_sel_i <= bib_sel_n; bib_sel_i++)
    bib_sel_add(bib_sel_k[bib_sel_i])
  if (keyfile != "") {
    while ((getline bib_sel_line < keyfile) > 0)
      bib_sel_add(bib_sel_line)
    close(keyfile)
  }
}

function bib_pass(raw) {
  bib_sep()
  print raw
}

function bib_entry(type, key) {
  if (BIB_SEL_ALL || (key in BIB_SEL) != invert + 0) {
    bib_sep()
    bib_emit(type, key)
  }
}