-- Take a single word from str, if posible. Returns the rest of the string and
-- the word taken.
function buffers.visualizers.lam.take_word(str)
- res, newstr = utf.match(str, "^(%a+)(.*)")
+ res, newstr = utf.match(str, "^(%a[%a%d_]+)(.*)")
return res, newstr or str
end
+-- Tries to match each of the patterns and returns the captures of the first
+-- matching pattern (up to 5 captures are supported). Returns nil when nothing
+-- matches.
+function buffers.visualizers.lam.match_mul(str, patterns)
+ for i, pat in ipairs(patterns) do
+ a, b, c, d, e = utf.match(str, pat)
+ if a then
+ return a, b, c, d, e
+ end
+ end
+ 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
+
+function buffers.visualizers.lam.do_subscripts(word)
+ local match_mul = buffers.visualizers.lam.match_mul
+ base, sub = match_mul(res, submatches)
+ if sub then
+ 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
+ -- Register that we've added this base
+ bases[base] = true
+ -- Add a pattern for this base
+ submatches[#submatches+1] = "^(" .. base .. ")([%a%d,]+)$"
+ end
+ end
+ return word
+end
+
function buffers.visualizers.lam.flush_line(str,nested)
local result, state = { }, 0
local finish, change = buffers.finish_state, buffers.change_state
local take_symbol = buffers.visualizers.lam.take_symbol
local take_word = buffers.visualizers.lam.take_word
+ local do_subscripts = buffers.visualizers.lam.do_subscripts
-- Set the colorscheme, which is used by finish_state and change_state
buffers.currentcolors = buffers.visualizers.lam.colors
-
while str ~= "" do
local found = false
- local res
+ local word, symbol
-- See if the next token is a word
- res, str = take_word(str)
- if res then
+ word, str = take_word(str)
+ if word then
if buffers.visualizers.lam.keywords[res] then
- -- Make all keywors bold
- res = "{\\bold " .. res .. "}"
+ -- Make all keywords bold
+ word = "{\\bold " .. word .. "}"
+ else
+ -- Process any subscripts in the word
+ word = do_subscripts(word)
end
- -- All other words are unmodified
else
-- The next token is not a word, it must be a symbol
- res, str = take_symbol(str)
+ symbol, str = take_symbol(str)
end
-- Append the resulting token
- result[#result+1] = res
+ result[#result+1] = word or symbol
end
state = finish(state, result)
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: