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Diffstat (limited to 'ipl/progs/latexidx.icn')
| -rw-r--r-- | ipl/progs/latexidx.icn | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/ipl/progs/latexidx.icn b/ipl/progs/latexidx.icn new file mode 100644 index 0000000..cca1fa0 --- /dev/null +++ b/ipl/progs/latexidx.icn @@ -0,0 +1,141 @@ +############################################################################ +# +# File: latexidx.icn +# +# Subject: Program to process LaTeX idx file +# +# Author: David S. Cargo +# +# Date: April 19, 1989 +# +############################################################################ +# +# This file is in the public domain. +# +############################################################################ +# +# Input: +# +# A latex .idx file containing the \indexentry lines. +# +# Output: +# +# \item lines sorted in order by entry value, +# with page references put into sorted order. +# +# Processing: +# +# While lines are available from standard input +# Read a line containing an \indexentry +# Form a sort key for the indexentry +# If there is no table entry for it +# Then create a subtable for it and assign it an initial value +# If there is a table entry for it, +# But not an subtable entry for the actual indexentry +# Then create an initial page number set for it +# Otherwise add the page number to the corresponding page number set +# Sort the table of subtables by sort key value +# For all subtables in the sorted list +# Sort the subtables by indexentry values +# For all the indexentries in the resulting list +# Sort the set of page references +# Write an \item entry for each indexentry and the page references +# +# Limitations: +# +# Length of index handled depends on implementation limits of memory alloc. +# Page numbers must be integers (no roman numerals). Sort key formed by +# mapping to lower case and removing leading articles (a separate function +# is used to produce the sort key, simplifying customization) -- otherwise +# sorting is done in ASCII order. +# +############################################################################ + +procedure main() # no parameters, reading from stdin + local key_table, s, page_num, itemval, key, item_list, one_item + local page_list, refs + + key_table := table() # for items and tables of page sets + while s := read() do # read strings from standard input + { + # start with s = "\indexentry{item}{page}" + # save what's between the opening brace and the closing brace, + # and reverse it + s := reverse(s[upto('{',s)+1:-1]) + # giving s = "egap{}meti" + + # reversing allows extracting the page number first, thereby allowing + # ANYTHING to be in the item field + + # grab the "egap", reverse it, convert to integer, convert to set + # in case of conversion failure, use 0 as the default page number + page_num := set([integer(reverse(s[1:upto('{',s)])) | 0]) + + # the reversed item starts after the first closing brace + # grab the "meti", reverse it + itemval := reverse(s[upto('}', s)+1:0]) + + # allow the sort key to be different from the item + # reform may be customized to produce different equivalence classes + key := reform(itemval) + + # if the assigned value for the key is null + if /key_table[key] + then + { + # create a subtable for the key and give it its initial value + key_table[key] := table() + key_table[key][itemval] := page_num + } + + # else if the assigned value for the itemval is null + # (e. g., when the second itemval associated with a key is found) + else if /key_table[key][itemval] + + # give it its initial value + then key_table[key][itemval] := page_num + + # otherwise just add it to the existing page number set + else key_table[key][itemval] ++:= page_num + } + + # now that all the input has been read.... + # sort keys and subtables by key value + key_table := sort(key_table, 3) + + # loop, discarding the sort keys + while get(key_table) do + { + # dequeue and sort one subtable into a list + # sort is strictly by ASCII order within the equivalence class + item_list := sort(get(key_table), 3) + + # loop, consuming the item and the page number sets as we go + while one_item := get(item_list) do + { + # convert the page number set into a sorted list + page_list := sort(get(item_list)) + + # dequeue first integer and convert to string + refs := string(get(page_list)) + + # dequeue rest of page nums and append + while (refs ||:= ", " || string(get(page_list))) + + write("\\item ", one_item, " ", refs) + } + } + return +end + +# reform - modify the item to enforce sort order appropriately +# This could do much more. For example it could strip leading braces, +# control sequences, quotation marks, etc. It doesn't. Maybe later. +procedure reform(item) + item := map(item) # map to lowercase +# drop leading article if present + if match("a ", item) then return item[3:0] + if match("an ", item) then return item[4:0] + if match("the ", item) then return item[5:0] + return item +end |