From b5c7b3b79746ee07210d1b5b93bd0ce83b8e6d29 Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <m.kooijman@student.utwente.nl>
Date: Mon, 29 Jun 2009 17:09:59 +0200
Subject: [PATCH 1/1] Update pret-lam to a new version of by
 begin/end_of_buffer patch.

Now, begin_of_buffer and end_of_buffer are always called, even for \type{}
commands. This greatly simplifies their contents and hackyness.

Also add some comments.
---
 pret-lam.lua | 47 +++++++++++++++++++----------------------------
 1 file changed, 19 insertions(+), 28 deletions(-)

diff --git a/pret-lam.lua b/pret-lam.lua
index 1011b19..c05f987 100644
--- a/pret-lam.lua
+++ b/pret-lam.lua
@@ -17,6 +17,7 @@ buffers.visualizers.lam.colors = {
     "prettyfour"
 }
 
+-- Symbols that should have a different representation
 buffers.visualizers.lam.symbols = {
     [' '] = {repr = '\\obs '},
     ['_'] = {repr = '\\_'},
@@ -26,6 +27,8 @@ buffers.visualizers.lam.symbols = {
     ['*'] = {repr = '\\ast'},
 }
 
+
+-- Keywords that should be bold
 buffers.visualizers.lam.keywords = {
     ['case'] = {},
     ['of'] = {},
@@ -33,13 +36,11 @@ buffers.visualizers.lam.keywords = {
     ['in'] = {},
 }
 
-
+-- See if str starts with a symbol, and return the remaining string and that
+-- symbol. If no symbol from the table is matched, just returns the first
+-- character.  We can do a lookup directly, since symbols can be different in
+-- length, so we just loop over all symbols, trying them in turn.
 function buffers.visualizers.lam.take_symbol(str)
-    -- See if str starts with a symbol, and return the remaining
-    -- string and that symbol. If no symbol from the table is matched,
-    -- just returns the first character.
-    -- We can do a lookup directly, since symbols can be different in
-    -- length, so we just loop over all symbols, trying them in turn.
     for symbol,props in pairs(buffers.visualizers.lam.symbols) do
         -- Try to remove symbol from the start of str 
         symbol, newstr = utf.match(str, "^(" .. symbol .. ")(.*)")
@@ -78,23 +79,7 @@ function buffers.visualizers.lam.match_mul(str, patterns)
     return nil
 end
 
-function buffers.visualizers.lam.begin_of_buffer()
-    -- Initially allow subscripts using _ or just appending a number (later,
-    -- we will add extra patterns here.
-    submatches = {"^(.*)_([%a%d,]+)$", "^(.*[^%d])(%d+)$"}
-    -- This stores all the bases we've encountered so far (to prevent
-    -- duplicates). For each of them there will be a pattern in submatches
-    -- above.
-    bases = {}
-end
-
-function buffers.visualizers.lam.end_of_buffer()
-    -- Reset submatches and bases, since flush_line can be called without
-    -- begin / end_of_buffer for \type.
-    buffers.visualizers.lam.begin_of_buffer()
-    bases = nil
-end
-
+-- Find any subscripts in the given word and typeset them
 function buffers.visualizers.lam.do_subscripts(word)
     local match_mul = buffers.visualizers.lam.match_mul
     base, sub = match_mul(res, submatches)
@@ -102,7 +87,7 @@ function buffers.visualizers.lam.do_subscripts(word)
         word = base .. "\\low{" .. sub .. "}"
         -- After a word has been used as a base, allow subscripts
         -- without _, even for non-numbers.
-        if bases and not bases[base] then
+        if not bases[base] then
             -- Register that we've added this base
             bases[base] = true
             -- Add a pattern for this base
@@ -112,6 +97,16 @@ function buffers.visualizers.lam.do_subscripts(word)
     return word
 end
 
+function buffers.visualizers.lam.begin_of_buffer(type, name)
+    -- Initially allow subscripts using _ or just appending a number (later,
+    -- we will add extra patterns here.
+    submatches = {"^(.*)_([%a%d,]+)$", "^(.*[^%d])(%d+)$"}
+    -- This stores all the bases we've encountered so far (to prevent
+    -- duplicates). For each of them there will be a pattern in submatches
+    -- above.
+    bases = {}
+end
+
 function buffers.visualizers.lam.flush_line(str,nested)
     local result, state = { }, 0
     local finish, change = buffers.finish_state, buffers.change_state
@@ -146,8 +141,4 @@ function buffers.visualizers.lam.flush_line(str,nested)
     buffers.flush_result(result,nested)
 end
 
--- Call end_of_buffer once to set up submatches (since \type doesn't call
--- begin_of_buffer / end_of_buffer).
-buffers.visualizers.lam.end_of_buffer()
-
 -- vim: set sw=4 sts=4 expandtab ai:
-- 
2.30.2