cortav  Check-in [76fe4885f4]

* [`$[$macro] [$arg1]|[$arg2]|[$argn]…] invokes a block-level macro with the supplied arguments, and can be followed by a property override definition list the same way embed and resource lines can. note that while both [`$[$id]] and [`&[$id]] can be used to instantiate resources of type [`text/x.cortav], there is a critical difference: [`$[$id]] renders out the sub-document separately each time it is named, allowing for parameter expansion and for context variables to be overridden for each invocation. by contrast, [`&[$id]] can only insert copies of the same render; no parameters can be passed and context variables will be expanded to their value at the time the resource was defined.
** [`$mymacro arg 1|arg 2|arg 3]
* [*horizontal rule] ([`\---]): inserts a horizontal rule or other context break; does not end the section. must be followed by newline. underlines can also be used in place of dashes ([`___], [`-_-], [`__-__-__] etc), as can horizontal unicode box drawing characters ([`─ ━ ┈] etc).
* [*page break] ([`\^^]): for formats that support pagination, like EPUB or HTML (when printed), indicates that the rest of the current page should be blank. for formats that do not, extra margins will be inserted. does not create a new section
* [*page rule] ([`\^-^]): inserts a page break for formats that support them, and a horizontal rule for formats that do not. does not create a new section. comprised of any number of horizontal rule characters surrounded by a pair of carets (e.g. [`^-^] [`^_^] [`^----^] [`^__--^] [`^┈┈┈┈┈^])
* [*table cells] ([`+ |]): see [>ex.tab table examples].
* [*equations] ([`=]): block-level equations can be inserted with the [`=] sequence
* [*cross-references] ([`=>] [`⇒]): inserts a block-level link. uses the same syntax as span links ([`⇒[$ident] [$styled-text]]). can be followed by a caption to add a longer descriptive text. especially useful for gemtext output. ident can be omitted to cross-reference, for example, a physical book.


* [*empty lines] (that is, lines consisting of nothing but whitespace) constitute a [!break], which terminates multiline objects that do not have a dedicated termination sequence, for example lists and asides.

##onspans styled text
most blocks contain a sequence of spans. these spans are produced by interpreting a stream of [*styled-text] following the control sequence. styled-text is a sequence of codepoints potentially interspersed with escapes. an escape is formed by an open square bracket [`\[] followed by a [*span control sequence], and arguments for that sequence like more styled-text. escapes can be nested.

* strong {obj *|styled-text}: causes its text to stand out from the narrative, generally rendered as bold or a brighter color.
* emphatic {obj !|styled-text}: indicates that its text should be spoken with emphasis, generally rendered as italics

* [`$[$macro] [$arg1]|[$arg2]|[$argn]…] invokes a block-level macro with the supplied arguments, and can be followed by a property override definition list the same way embed and resource lines can. note that while both [`$[$id]] and [`&[$id]] can be used to instantiate resources of type [`text/x.cortav], there is a critical difference: [`$[$id]] renders out the sub-document separately each time it is named, allowing for parameter expansion and for context variables to be overridden for each invocation. by contrast, [`&[$id]] can only insert copies of the same render; no parameters can be passed and context variables will be expanded to their value at the time the resource was defined.
** [`$mymacro arg 1|arg 2|arg 3]
* [*horizontal rule] ([`\---]): inserts a horizontal rule or other context break; does not end the section. must be followed by newline. underlines can also be used in place of dashes ([`___], [`-_-], [`__-__-__] etc), as can horizontal unicode box drawing characters ([`─ ━ ┈] etc).
* [*page break] ([`\^^]): for formats that support pagination, like EPUB or HTML (when printed), indicates that the rest of the current page should be blank. for formats that do not, extra margins will be inserted. does not create a new section
* [*page rule] ([`\^-^]): inserts a page break for formats that support them, and a horizontal rule for formats that do not. does not create a new section. comprised of any number of horizontal rule characters surrounded by a pair of carets (e.g. [`^-^] [`^_^] [`^----^] [`^__--^] [`^┈┈┈┈┈^])
* [*table cells] ([`+ |]): see [>ex.tab table examples].
* [*equations] ([`=]): block-level equations can be inserted with the [`=] sequence
* [*cross-references] ([`=>] [`⇒]): inserts a block-level link. has two forms for the sake of gemtext compatibility. [$styled-text] is a descriptive text of the destination. especially useful for menus and gemtext output.
** the cortav syntax is [`=>[$ident] [$styled-text]], where [$ident] is an identifier; links to the same destination as [` \[>[$ident] [$styled-text]\]] would
** the compatibility syntax is [`=> [$uri] [$styled-text]] (note the space before [$uri]!). instead of taking an identifier for an object in the document, it directly accepts a URI. note that this is not formally equivalent to gemtext's link syntax, which also allows paths in place of URIs; [`cortav] does not. the gemtext line ["=> /somewhere] would need to be expressed as ["=> file:/somewhere], and ["=> /somewhere?key=val] as ["http:/somewhere?key=val] (or ["gemini:/somewhere?key=val], if the result is to be served over a gemini server).
* [*empty lines] (that is, lines consisting of nothing but whitespace) constitute a [!break], which terminates multiline objects that do not have a dedicated termination sequence, for example lists and asides.

##onspans styled text
most blocks contain a sequence of spans. these spans are produced by interpreting a stream of [*styled-text] following the control sequence. styled-text is a sequence of codepoints potentially interspersed with escapes. an escape is formed by an open square bracket [`\[] followed by a [*span control sequence], and arguments for that sequence like more styled-text. escapes can be nested.

* strong {obj *|styled-text}: causes its text to stand out from the narrative, generally rendered as bold or a brighter color.
* emphatic {obj !|styled-text}: indicates that its text should be spoken with emphasis, generally rendered as italics

			flush()
			buf.header = c == '+'
		elseif c == ':' then
			local lst = l:sub(p.byte-#c,p.byte-#c)
			local nxt = l:sub(p.next.byte,p.next.byte)
			if lst == '|' or lst == '+' and l:sub(p.byte-2,p.byte-2) ~= '\\' then
				buf.align = 'left'
			elseif nxt == '|' or nxt == '|' then
				if buf.align == 'left' then
					buf.align = 'center'
				else
					buf.align = 'right'
				end
			else
				buf.str = buf.str .. c
................................................................................
		j:hook('block_table_insert', c, tbl, l)
		j:hook('block_table_row_insert', c, tbl, tbl.rows[1], l)
	end
end

local function insert_link_block(seq)
	return blockwrap(function(s,c)
		local r = s:sub(#seq):gsub('^%s+','') -- chomp
		local uri, txt = r:match('^([^%s]*)%s*(.*)$')
		return {

			uri = ss.uri(uri);

			label = ct.parse_span(txt, c);
		}
	end)
end

ct.ctlseqs = {
	{seq = '.', fn = insert_paragraph};
	{seq = '¶', fn = insert_paragraph};

			flush()
			buf.header = c == '+'
		elseif c == ':' then
			local lst = l:sub(p.byte-#c,p.byte-#c)
			local nxt = l:sub(p.next.byte,p.next.byte)
			if lst == '|' or lst == '+' and l:sub(p.byte-2,p.byte-2) ~= '\\' then
				buf.align = 'left'
			elseif nxt == '|' or nxt == '+' then
				if buf.align == 'left' then
					buf.align = 'center'
				else
					buf.align = 'right'
				end
			else
				buf.str = buf.str .. c
................................................................................
		j:hook('block_table_insert', c, tbl, l)
		j:hook('block_table_row_insert', c, tbl, tbl.rows[1], l)
	end
end

local function insert_link_block(seq)
	return blockwrap(function(s,c)
		local r = s:sub(#seq+1)
		local k, uri, txt = r:match('^(%s*)([^%s]*)%s*(.*)$')
		return {
			kind = 'link';
			uri = (k~='') and ss.uri(uri) or nil;
			ref = (k=='') and uri or nil;
			spans = ct.parse_span(txt, c);
		}
	end)
end

ct.ctlseqs = {
	{seq = '.', fn = insert_paragraph};
	{seq = '¶', fn = insert_paragraph};

			h1 {
				page-break-before: always;
			}
			h1,h2,h3,h4,h5,h6 {
				page-break-after: avoid;
			}
		]];








































	}

	local stylesNeeded = {
		flags = {};
		order = {};
	}
	local function addStyle(sty)
................................................................................

	local renderJob = doc:job('render_html', nil, render_state_handle)
	doc.stage.job = renderJob;

	local runhook = function(h, ...)
		return renderJob:hook(h, render_state_handle, ...)
	end



















































	local tagproc do
		local html_open = function(t,attrs)
			if attrs then
				return t .. ss.reduce(function(a,b) return a..b end, '',
					ss.map(function(v,k)
						if v == true
................................................................................
		end

		function span_renderers.raw(v,b,s)
			return htmlSpan(v.spans, b, s)
		end

		function span_renderers.link(sp,b,s)
			local dest_o, _, dest_s = b.origin:ref(sp.ref)
			local href
			if dest_o == nil then
				-- link is to the section itself
				href = '#' .. getSafeID(dest_s)
			else
-- 				if sp.addr then href = sp.addr else
				if type(dest_o) == 'table' then
					href = '#' .. getSafeID(dest_o)
				else -- URI in reference
					local uri = ss.uri(dest_o)
					if uri.class[1] == 'file'
					or uri.class[1] == 'asset' then
						if uri.namespace == 'localhost' then
							-- emit an actual file url
							href = 'file://' .. uri:construct('path','frag')
						elseif uri.namespace == nil then
							-- this is gonna be tricky. first we establish the location
							-- of the CWD/asset base relative to the output file (if any;
							-- assume equivalent otherwise) then express the difference
							-- as a directory prefix.
							-- jk tho for now we just emit the path+frag sadlol TODO
							href = uri:construct('path','frag')
						else
							b.origin:fail('file: URI namespace must be empty or “localhost” for HTML links; others are not meaningful (offending URI: “%s”)', dest_o)
						end
					elseif uri:canfetch() == 'http' then
						local sc = 'http'
						if uri.class[1] == 'https' or uri.class[2] == 'tls' then
							sc = 'https'
						end
						if uri.namespace == nil and uri.auth == nil and uri.svc == nil then
							-- omit the scheme so we can use a relative path
							href = uri:construct('path','query','frag')
						else
							uri.class = {sc}
							href = tostring(uri)
						end
					else href = tostring(uri) end
				end
			end
			return tag('a',{href=href},next(sp.spans) and htmlSpan(sp.spans,b,s) or href)
		end

		span_renderers['line-break'] = function(sp,b,s)
			return elt('br')
		end

		function span_renderers.macro(m,b,s)
................................................................................
				else
					-- handle other uses of labels here
				end
			end;
			['list-item'] = function(b,s)
				return tag('li', nil, sr.htmlSpan(b.spans, b, s), b)
			end;












			table = function(b,s)
				local tb = {}
				for i, r in ipairs(b.rows) do
					local row = {}
					for i, c in ipairs(r) do
						table.insert(row, tag(c.header and 'th' or 'td',
						{align=c.align}, sr.htmlSpan(c.spans, b)))
................................................................................

		function block_renderers.embed(b,s)
			local obj
			if b.rsrc
				then obj = b.rsrc
				else obj = b.origin:ref(b.ref)
			end
			local function htmlURI(u)
				local family = u:canfetch()
				if  family == 'file' or
					(family == 'http' and u.namespace == nil) then
					-- TODO asset:
					return u.path
				else
					return tostring(u)
				end
			end
			local function uriForSource(s)
				if s.mode == 'link' or s.mode == 'auto' then
					return htmlURI(s.uri)
				elseif s.mode == 'embed' then
					local mime = s.mime:clone()
					mime.opts = {}
					return string.format('data:%s;base64,%s', mime, ss.str.b64e(s.raw))

			h1 {
				page-break-before: always;
			}
			h1,h2,h3,h4,h5,h6 {
				page-break-after: avoid;
			}
		]];
		linkBlock = [[
			a[href].link {
				position: relative;
				display: block;
				padding: .5em;
				padding-right: 1.5em;
				border: 1px solid @tone(0.2 30);
				background: @tone(0.05 30);
				font-size: 1.1em;
				margin: 0 1em;
				text-decoration: none;
				color: @tone(0.8 30);
			}
			a[href].link + a[href].link {
				margin-top: -1px;
			}
			a[href].link:hover {
				border-color: @tone(0.3 30);
				background: @tone(0.2 30);
				color: @tone(0.95 30);
			}
			a[href].link:hover + a[href].link {
				margin-top: 0;
				border-top: none;
			}
			a[href].link::after {
				display: block;
				position: absolute;
				right: .5em;
				content: "→";
				top: 50%;
				margin-left: 1em;
				font-size: 1.8em;
				transform: translateY(-50%);
				color: @tone(0.3 30);
			}
			a[href].link:hover::after {
				color: @tone(0.7 30);
			}
		]];
	}

	local stylesNeeded = {
		flags = {};
		order = {};
	}
	local function addStyle(sty)
................................................................................

	local renderJob = doc:job('render_html', nil, render_state_handle)
	doc.stage.job = renderJob;

	local runhook = function(h, ...)
		return renderJob:hook(h, render_state_handle, ...)
	end

	local function htmlURI(uri)
		local family = uri:canfetch()
		if family == 'file' then
			if uri.namespace == 'localhost' then
				-- emit an actual file url
				return 'file://' .. uri:construct('path','frag')
			elseif uri.namespace == nil then
				-- this is gonna be tricky. first we establish the location
				-- of the CWD/asset base relative to the output file (if any;
				-- assume equivalent otherwise) then express the difference
				-- as a directory prefix.
				-- jk tho for now we just emit the path+frag sadlol TODO
				if uri.path == nil and uri.frag then
					-- file:#sec links to #sec within the current document
					return uri:part 'frag'
				else
					return uri:construct('path','frag')
				end
			else
				b.origin:fail('file: URI namespace must be empty or “localhost” for HTML links; others are not meaningful (offending URI: “%s”)', uri.raw)
			end
		elseif family == 'http' then
			local sc = 'http'
			if uri.class[1] == 'https' or uri.class[2] == 'tls' then
				sc = 'https'
			end
			if uri.namespace == nil and uri.auth == nil and uri.svc == nil then
				-- omit the scheme so we can use a relative path
				return uri:construct('path','query','frag')
			else
				uri.class = {sc}
				return tostring(uri)
			end
		else return tostring(uri) end
	end

	local function idLink(id,b)
		local dest_o, _, dest_s = b.origin:ref(id)
		if dest_o == nil then
			-- link is to the section itself
			return '#' .. getSafeID(dest_s)
		else
			if type(dest_o) == 'table' then
				return '#' .. getSafeID(dest_o)
			else -- URI in reference
				return htmlURI(ss.uri(dest_o))
			end
		end
	end

	local tagproc do
		local html_open = function(t,attrs)
			if attrs then
				return t .. ss.reduce(function(a,b) return a..b end, '',
					ss.map(function(v,k)
						if v == true
................................................................................
		end

		function span_renderers.raw(v,b,s)
			return htmlSpan(v.spans, b, s)
		end

		function span_renderers.link(sp,b,s)

			local href = idLink(sp.ref,b)







































			return tag('a',{href=href}, next(sp.spans) and htmlSpan(sp.spans,b,s) or href)
		end

		span_renderers['line-break'] = function(sp,b,s)
			return elt('br')
		end

		function span_renderers.macro(m,b,s)
................................................................................
				else
					-- handle other uses of labels here
				end
			end;
			['list-item'] = function(b,s)
				return tag('li', nil, sr.htmlSpan(b.spans, b, s), b)
			end;
			link = function(b,s)
				addStyle 'linkBlock'
				local href
				if b.uri then
					href = htmlURI(b.uri)
				elseif b.ref then
					href = idLink(b.ref, b)
				end
				local sp = sr.htmlSpan(b.spans, b, s)
				return tag('div', {},
					catenate{tag('a',{class='link', href=href},sp)})
			end;
			table = function(b,s)
				local tb = {}
				for i, r in ipairs(b.rows) do
					local row = {}
					for i, c in ipairs(r) do
						table.insert(row, tag(c.header and 'th' or 'td',
						{align=c.align}, sr.htmlSpan(c.spans, b)))
................................................................................

		function block_renderers.embed(b,s)
			local obj
			if b.rsrc
				then obj = b.rsrc
				else obj = b.origin:ref(b.ref)
			end










			local function uriForSource(s)
				if s.mode == 'link' or s.mode == 'auto' then
					return htmlURI(s.uri)
				elseif s.mode == 'embed' then
					local mime = s.mime:clone()
					mime.opts = {}
					return string.format('data:%s;base64,%s', mime, ss.str.b64e(s.raw))