"prettyfour"
}
+-- Symbols that should have a different representation
buffers.visualizers.lam.symbols = {
[' '] = {repr = '\\obs '},
['_'] = {repr = '\\_'},
-- The default * sits very high above the baseline, \ast (u+2217) looks
-- better.
['*'] = {repr = '\\ast'},
+ ['~'] = {repr = '\\sim'},
}
+
+-- Keywords that should be bold
buffers.visualizers.lam.keywords = {
['case'] = {},
['of'] = {},
['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 .. ")(.*)")
-- 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[%a%d_]+)(.*)")
+ -- A word must always start with a-z (in particular, λ is not a valid
+ -- start of a word).
+ res, newstr = utf.match(str, "^([a-zA-Z][%a%d_]+)(.*)")
return res, newstr or str
end
return 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)
+ if sub then
+ word = base .. "\\low{" .. sub .. "}"
+ -- After a word has been used as a base, allow subscripts
+ -- without _, even for non-numbers.
+ if 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,]+)$"
+ end
+ end
+ return word
+end
+
+function buffers.visualizers.lam.begin_of_buffer(type, name)
+ -- Initially allow subscripts using _ or just appending a number (later,
+ -- we will add extra patterns here.
+ submatches = {"^(.*)_([%a%d,]+)$", "^(.*[^%d])(%d+)$"}
+ -- This stores all the bases we've encountered so far (to prevent
+ -- duplicates). For each of them there will be a pattern in submatches
+ -- above.
+ bases = {}
+end
+
function buffers.visualizers.lam.flush_line(str,nested)
local result, state = { }, 0
local finish, change = buffers.finish_state, buffers.change_state
local take_symbol = buffers.visualizers.lam.take_symbol
local take_word = buffers.visualizers.lam.take_word
- local match_mul = buffers.visualizers.lam.match_mul
+ local do_subscripts = buffers.visualizers.lam.do_subscripts
-- Set the colorscheme, which is used by finish_state and change_state
buffers.currentcolors = buffers.visualizers.lam.colors
-
while str ~= "" do
local found = false
local word, symbol
-- Make all keywords bold
word = "{\\bold " .. word .. "}"
else
- -- Allow subscripts using _ or just appending a number.
- base, sub = match_mul(res, {"^(.*)_([%a%d,]+)$", "^(.*[^%d])(%d*)$"})
- if sub then
- word = base .. "\\low{" .. sub .. "}"
- end
+ -- Process any subscripts in the word
+ word = do_subscripts(word)
end
else
-- The next token is not a word, it must be a symbol