174 lines
3.9 KiB
Text
174 lines
3.9 KiB
Text
# Markdown to HTML
|
|
|
|
RETRO's source files generally use a subset of Markdown for
|
|
formatting. This is a small tool to convert this into HTML.
|
|
|
|
## Features
|
|
|
|
Recognizes:
|
|
|
|
- lists
|
|
- indented code blocks
|
|
- paragraphs
|
|
- headers
|
|
- fenced code blocks
|
|
- horizontal rules
|
|
- *inline* _formatting_ elements
|
|
|
|
## Limitations
|
|
|
|
This only supports a limited subset of full Markdown. I am
|
|
not adding support for the various linking formats, ordered
|
|
lists, underlined headers, doubled asterisk, doubled
|
|
underscores, multiple line/paragraph list entries, or images.
|
|
|
|
The CSS used is extracted from the end of this file. I only
|
|
do a tiny bit of styling by default; just enough to ensure
|
|
that code blocks are easily identified.
|
|
|
|
----
|
|
|
|
## The Code
|
|
|
|
Begin by locating and extracting the CSS.
|
|
|
|
~~~
|
|
'<style> s:put nl
|
|
FALSE sys:name [ over [ '##_CSS s:eq? or ] -if; s:put nl ] file:for-each-line
|
|
drop
|
|
'</style> s:put nl
|
|
~~~
|
|
|
|
The first couple of words are a variation of `s:put` that
|
|
generates HTML codes for specific characters. This ensures
|
|
that code output displays correctly.
|
|
|
|
~~~
|
|
:c:put<code>
|
|
$< [ '< s:put ] case
|
|
$> [ '> s:put ] case
|
|
$& [ '& s:put ] case
|
|
ASCII:SPACE [ ' s:put ] case
|
|
c:put ;
|
|
|
|
:s:put<code> [ c:put<code> ] s:for-each ;
|
|
~~~
|
|
|
|
For regular text, there are a couple of inline formatting things
|
|
to deal with.
|
|
|
|
~~~
|
|
'Emphasis var
|
|
'Strong var
|
|
'Escape var
|
|
'Code var
|
|
|
|
:format
|
|
@Escape [ &Escape v:on ] if;
|
|
$` [ @Escape [ &Escape v:off $* c:put ] if;
|
|
@Code n:zero? [ '<tt_style='display:inline'> &Code v:on ]
|
|
[ '</tt> &Code v:off ] choose s:put ] case
|
|
$* [ @Escape @Code or [ &Escape v:off $* c:put ] if;
|
|
@Strong n:zero? [ '<strong> &Strong v:on ]
|
|
[ '</strong> &Strong v:off ] choose s:put ] case
|
|
$_ [ @Escape @Code or [ &Escape v:off $_ c:put ] if;
|
|
@Emphasis n:zero? [ '<em> &Emphasis v:on ]
|
|
[ '</em> &Emphasis v:off ] choose s:put ] case
|
|
c:put ;
|
|
|
|
:s:put<formatted> [ format ] s:for-each ;
|
|
~~~
|
|
|
|
Next, handling of code blocks.
|
|
|
|
The fences need to start and end with `~~~` on a line by
|
|
itself. (This will also handle test blocks using three
|
|
bacticks as well)
|
|
|
|
~~~
|
|
'Block var
|
|
:in-block? @Block ;
|
|
:block? dup [ '~~~ s:eq? ] [ '``` s:eq? ] bi or ;
|
|
:toggle drop @Block n:zero? !Block ;
|
|
:format:block '<tt> s:put s:put<code> '</tt> s:put nl ;
|
|
~~~
|
|
|
|
After this, I define detection and formatting of headers. The
|
|
headers should look like:
|
|
|
|
# Level 1
|
|
## Level 2
|
|
### Level 3
|
|
|
|
~~~
|
|
:header?
|
|
dup [ '# s:begins-with? ]
|
|
[ '## s:begins-with? ]
|
|
[ '### s:begins-with? ] tri or or ;
|
|
|
|
:format:head
|
|
ASCII:SPACE s:split
|
|
'# [ '<h1> s:put n:inc s:put '</h1> s:put nl ] s:case
|
|
'## [ '<h2> s:put n:inc s:put '</h2> s:put nl ] s:case
|
|
'### [ '<h3> s:put n:inc s:put '</h3> s:put nl ] s:case
|
|
drop ;
|
|
~~~
|
|
|
|
Indented code blocks are lines indented by four spaces.
|
|
|
|
~~~
|
|
:code? dup '____ s:begins-with? ;
|
|
:format:code '<tt> s:put #4 + s:put<code> '</tt> s:put nl ;
|
|
~~~
|
|
|
|
Horizonal rules consist of four or more - characters on
|
|
a line. E.g.,
|
|
|
|
----
|
|
--------
|
|
|
|
~~~
|
|
:rule? dup '---- s:begins-with? ;
|
|
:format:rule drop '<hr> s:put nl ;
|
|
~~~
|
|
|
|
Lists start with a `-` or `*`, followed by a space, then
|
|
the item text.
|
|
|
|
~~~
|
|
:list? dup [ '-_ s:begins-with? ] [ '*_ s:begins-with? ] bi or ;
|
|
:format:list '<li> s:put #2 + s:put<formatted> '</li> s:put nl ;
|
|
~~~
|
|
|
|
Blank lines denote paragraph breaks.
|
|
|
|
~~~
|
|
:blank? dup s:length n:zero? ;
|
|
~~~
|
|
|
|
~~~
|
|
:format
|
|
block? [ toggle ] if;
|
|
in-block? [ format:block ] if;
|
|
blank? [ drop '<p> s:put nl ] if;
|
|
header? [ format:head ] if;
|
|
code? [ format:code ] if;
|
|
list? [ format:list ] if;
|
|
rule? [ format:rule ] if;
|
|
s:put<formatted> nl ;
|
|
|
|
#0 sys:argv [ format ] file:for-each-line
|
|
~~~
|
|
|
|
This concludes the Markdown (subset) in RETRO utility.
|
|
|
|
## CSS
|
|
|
|
tt, pre {
|
|
background: #eee;
|
|
color: #111;
|
|
font-family: monospace;
|
|
white-space: pre;
|
|
display: block;
|
|
width: 100%;
|
|
}
|