From: Matthijs Kooijman Date: Fri, 28 Aug 2009 13:23:46 +0000 (+0200) Subject: Make pret-lam preserve alignment using whitespace. X-Git-Tag: final-thesis~274 X-Git-Url: https://git.stderr.nl/gitweb?a=commitdiff_plain;h=41753b358251eb737709bbc4172cb551ef41ef87;p=matthijs%2Fmaster-project%2Freport.git Make pret-lam preserve alignment using whitespace. This is slightly complicated, but it should work properly in most cases. --- diff --git a/Utils/Formats.tex b/Utils/Formats.tex index 993a988..aae99ed 100644 --- a/Utils/Formats.tex +++ b/Utils/Formats.tex @@ -25,3 +25,7 @@ background=, frame=off] +\def\setwidthof#1\to#2% +{\bgroup +\setbox\scratchbox\hbox{#1}% +\expanded{\egroup\def\noexpand#2{\the\wd\scratchbox}}} diff --git a/pret-lam.lua b/pret-lam.lua index 54acfd1..98244b0 100644 --- a/pret-lam.lua +++ b/pret-lam.lua @@ -35,6 +35,12 @@ local keywords = { ['in'] = {}, } +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 @@ -101,9 +107,63 @@ local function do_subscripts(word) return word end -local in_block = 0 -local submatches = {} -local bases = {} +-- 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 @@ -135,7 +195,9 @@ function vis.begin_of_display() -- above. bases = {} end + indentlines = {} end + -- Make things work for inline typeing (e.g., \type{}) as well. vis.begin_of_inline = vis.begin_of_display @@ -144,6 +206,7 @@ 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 = colors while str ~= "" do @@ -167,7 +230,7 @@ function vis.flush_line(str,nested) -- Append the resulting token result[#result+1] = word or symbol end - + state = finish(state, result) buffers.flush_result(result,nested) end