Re: syntax

[Hans Hagen <pragma@wxs.nl>]

Siep Kroonenberg wrote:

> - Does Context provide for styles as in Word: a set of typographic
> specifications (font, leading, h&j, space before and after) separate
> from any sectioning hierarchy, or is it necessary to write those from
> scratch as macros?

Most commands have some before/after (voor/na) hooks. These are normally
used for spacing: voor={\blanko[groot]}, but you can use them for other
things too. Font switches normally take place with the style (letter)
parameter. In some occasions there is 'afstand', 'korps', 'binnen',
'links', 'rechts', etc. 

> - Is the following syntax safe:
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>   \some_context_macro
> % comment
>     [parameter]

Yes. Try for instance 

\setuphead
  % comment 
  [chapter]
  % comment 
  [style=bold]

TeX ignores spaces atthe beginningof the line, so the comment becomes
one space, and the context argument handler takes care of such spaces.   

> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 
> - I am trying to define typography for a header:
> 
> \setuphead[subject]
>   [before=\blank,
>    after=\blank[small],
>    style={\switchtobodyfont[sans,16pt]\bf}]

Use switched around {\blank[small]}. Unfortunately TeX's normal argument
handling capabilities are not able to handle nested things (in this case
nested []). Technically, everything between a pair of [] is picked up,
and in your case 
the after small ends the parameter list.  

> This only seems to compile if I replace `after' with `\c!after', and
> even then I get a full instead of half a blank line.

I suppose you run the english context. \c!after is illegal (at least
untill context is english low level), but \c!na should work, that is,
when the set up commands are surrounded by \unprotect \protect (makes !
? @ letter). But such rather low level dirty settings (c! and v!) are
only needed for international setups. 

> If I try C-style indentation:
> 
> \setuphead[subject]
>   [before=\blank,
>    after=\blank[small],
>    style={\switchtobodyfont[sans,16pt]\bf
>    }
>   ]

Spaces after the first [ and after commas are gobbled, but everything
between = and the next , or final ] makes up the value. 

% context style indentation: -)

\setuphead
  [subject]
  [before=\blank,
   after={\blank[small]},
   style={\switchtobodyfont[sans,16pt]\bf}]

> then the style parameter seems to be ignored.

Some bonus tips:

  \definealternativestyle [siep] [{\switchtobodyfont[sans,16pt]\bf}] []

  \defineblank [alsosiep] [2*big]

  \setuphead[chapter][style=siep,before={\blank[alsosiep]}]

Especially the logical blank's can enforce consistency. 

Hans

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