local utf = unicode.utf8
-if not buffers then buffers = { } end
-if not buffers.visualizers then buffers.visualizers = { } end
-if not buffers.visualizers.lam then buffers.visualizers.lam = { } end
+local vis = buffers.newvisualizer("lam")
-buffers.visualizers.lam.colors = {
+local colors = {
"prettytwo",
"prettyone",
"prettythree",
"prettyfour"
}
-buffers.visualizers.lam.tokens = {
+-- Symbols that should have a different representation
+local symbols = {
[' '] = {repr = '\\obs '},
['_'] = {repr = '\\_'},
['->'] = {repr = '\\rightarrow'},
-- The default * sits very high above the baseline, \ast (u+2217) looks
-- better.
['*'] = {repr = '\\ast'},
- ['case'] = {style = 'bold'},
- ['of'] = {style = 'bold'},
- ['let'] = {style = 'bold'},
- ['in'] = {style = 'bold'},
+ ['~'] = {repr = '\\HDLine[width=.20 * \\the\\textwidth]'},
+ ['|'] = {repr = '\\char' .. utf.byte('|')},
+ ['$'] = {repr = '\\char' .. utf.byte('$')},
}
-function buffers.visualizers.lam.flush_line(str,nested)
+-- Keywords that should be bold
+local keywords = {
+ ['case'] = {},
+ ['of'] = {},
+ ['let'] = {},
+ ['letrec'] = {},
+ ['letnonrec'] = {},
+ ['in'] = {},
+ ['DEFAULT'] = {},
+}
+
+local in_block = 0
+local submatches = {}
+local bases = {}
+-- Store the last line for each indent level
+local indentlines = {}
+
+-- 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.
+local function take_symbol(str)
+ for symbol,props in pairs(symbols) do
+ -- Try to remove symbol from the start of str
+ symbol, newstr = utf.match(str, "^(" .. symbol .. ")(.*)")
+ if symbol then
+ -- Return this tokens repr, or just the token if it has no
+ -- repr.
+ res = props.repr or symbol
+ -- Enclose the token in {\style .. }
+ if props.style then
+ res = "{\\" .. props.style .. " " .. res .. "}"
+ end
+ return res, newstr
+ end
+ end
+ -- No symbol found, just return the first character
+ return utf.match(str, "^(.)(.*)")
+end
+
+-- Take a single word from str, if posible. Returns the rest of the string and
+-- the word taken.
+local function take_word(str)
+ -- 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
+
+-- 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.
+local function 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
+
+-- Find any subscripts in the given word and typeset them
+local function do_subscripts(word)
+ 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 patterns for this base. First, the base with a single
+ -- letter or number subscript.
+ submatches[#submatches+1] = "^(" .. base .. ")([%a%d])$"
+ -- Seconde, the base with a longer prefix that includes at least
+ -- one of +-, (to catch things like ri+1, but not return).
+ submatches[#submatches+1] = "^(" .. base .. ")([%a%d]*[%-%+%,]+[%a%d%-%+%,]*)$"
+ end
+ end
+ return word
+end
+
+-- Do proper aligning for subsequent lines. For example, in
+-- foo = bar
+-- | baz
+-- We replace the spaces in the second line with a skip with the same with as
+-- "foo ", to align the | with the =.
+-- For this, we keep a table "indentlines", which contains all previous lines
+-- with smaller indent levels that are still "in scope" (e.g., have not yet
+-- been followed by a line with a smaller indent level). For example:
+-- line1
+-- line2
+-- line3
+-- line4
+-- line5
+-- After the last line, the table will contain:
+-- { 0 = "line1", 2 = " line4", 4 = " line5"}
+-- In other words, line3 is no longer in scope since it is "hidden" by
+-- line4, and line is no longer in scope since it is replaced by line4.
+local function do_indent(line)
+ newind, rest = utf.match(line, '^(%s*)(.*)')
+ prev = -1
+ -- Loop all the previous lines
+ for indent, unused in pairs(indentlines) do
+ if indent > #newind then
+ -- Remove any lines with a larger indent
+ indentlines[indent] = nil
+ elseif indent < #newind and indent > prev then
+ -- Find the last line (e.g, with the highest indent) with an
+ -- indent smaller than the new indent. This is the line from which
+ -- we need to copy the indent.
+ prev = indent
+ end
+ end
+
+ -- Always store this line, possibly overwriting a previous line with the
+ -- same indent
+ indentlines[#newind] = line
+
+ if prev ~= -1 then
+ -- If there is a previous line with a smaller indent, make sure we
+ -- align with it. We do this by taking a prefix from that previous
+ -- line just as long as our indent. This gives us a bunch of
+ -- whitespace, with a few non-whitespace characters. We find out the
+ -- width of this prefix, and put whitespace just as wide as that
+ -- prefix before the current line, instead of the whitespace
+ -- characters that were there.
+ -- Doing this is slightly risky, since the prefix might contain
+ -- unfinished markup (e.g., \foo{bar without the closing }). We might
+ -- need to solve this later.
+ copyind = utf.sub(indentlines[prev], 1, #newind)
+ setwidth = "\\setwidthof{" .. copyind .. "}\\to\\pretlamalignwidth"
+ hskip = "\\hskip\\pretlamalignwidth"
+ return "{" .. setwidth .. hskip .. "}" .. rest
+ end
+ -- No previous line? Just return the unmodified line then
+ return line
+end
+
+
+-- Mark the begin of a block of lambda formatted buffers or expressions. This
+-- means that, until you call end_of_block again, the subscript bases are
+-- shared. For example, if you have \lam{y1} some text \lam{yn} within a
+-- single block, the yn will properly get subscripted. Be sure to call
+-- end_of_block again!
+--
+-- Blocks can be partially nested, meaning that the block
+-- won't be closed until end_of_block was called exactly as often as
+-- begin_of_block. However, subscripts from the inner block can still
+-- influence subscripts in the outer block.
+function vis.begin_of_block()
+ vis.begin_of_display()
+ in_block = in_block + 1
+end
+
+-- Ends the current block
+function vis.end_of_block()
+ in_block = in_block - 1
+end
+
+function vis.begin_of_display()
+ if in_block == 0 then
+ -- Initially allow subscripts using _ or just appending a number (later,
+ -- we will add extra patterns here.
+ submatches = {"^(%a*)_([%a%d,]+)$", "^(%a+)([%d,]+)$"}
+ -- 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
+ indentlines = {}
+end
+
+
+-- Make things work for inline typeing (e.g., \type{}) as well.
+vis.begin_of_inline = vis.begin_of_display
+vis.end_of_inline = vis.end_of_display
+
+function vis.flush_line(str,nested)
local result, state = { }, 0
local finish, change = buffers.finish_state, buffers.change_state
+ str = do_indent(str)
-- Set the colorscheme, which is used by finish_state and change_state
- buffers.currentcolors = buffers.visualizers.lam.colors
-
+ buffers.currentcolors = colors
while str ~= "" do
- found = false
- for tok,props in pairs(buffers.visualizers.lam.tokens) do
- -- Try to remove tok from the start of str
- str, count = utf.gsub(str, "^" .. tok, "")
- if count ~= 0 then
- -- Replace the token with the repr, or just itself
- result[#result+1] = props.repr or tok
- -- Enclose the token in {\style .. }
- if props.style then
- result[#result] = "{\\" .. props.style ..
- " " .. result[#result] ..
- "}"
- end
- -- We found a token, now start over
- found = true
- break
+ local found = false
+ local word, symbol
+ -- See if the next token is a word
+ word, str = take_word(str)
+ if word then
+ if keywords[res] then
+ -- Make all keywords bold
+ word = "{\\bold " .. word .. "}"
+ else
+ -- Process any subscripts in the word
+ word = do_subscripts(word)
end
+ else
+ -- The next token is not a word, it must be a symbol
+ symbol, str = take_symbol(str)
end
- if not found then
- -- Take a full word, or a single character. Taking a full word is
- -- to prevent matching "in" in "bind" , for example.
- result[#result+1] = utf.match(str, "^%a+") or utf.sub(str, 1, 1)
- str = utf.sub(str, utf.len(result[#result]) + 1)
- end
+
+ -- Append the resulting token
+ result[#result+1] = word or symbol
end
+
state = finish(state, result)
buffers.flush_result(result,nested)
end
projects / matthijs / master-project / report.git / blobdiff