TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
A modernized T
E
X
Previously, on Star T
E
X TNG. . .
T
E
X’s strength is in the quality of its typesetting, not in its
programmatic interface.
Keep the typesetting functionality but provide. . .
A more modern and consistent API
Real programming capabilities
Still simple to use (at least for simple things)
Extensibility / customizability
4/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
Fitness of Lisp
Previously, on Star T
E
X TNG. . .
Existing approaches are heterogeneous
What about a fully integrated approach ?
Industrial-scale general purpose language
Multi-paradigm
Highly optimizable
Pletora of libraries
Scripting / extension language
Highly dynamic
Highly reflexive
Easy to learn (no syntax)
5/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
This is where we start
Not very T
E
Xy. . .
cl-typesetting Hello World
( defun first−document (& key ( f i l e "/tmp/texput.pdf" ) )
( t t : with−document ( )
( l e t ( ( c ont e n t ( t t : compile− t e x t ( )
( t t : par agraph ( ) "This is some text." ) ) ) )
( t t : draw−pages cont e n t )
(when p d f :∗ page∗ ( ty p e s et : f i na l i ze − p a g e pd f :∗ page ∗ ) )
( t t : write−document f i l e ) ) ) )
8/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
L
A
T
E
X-like programmatic layer: step 2
Less full of Lisp idioms
Non lispy accessors (although for constants)
Non lispy function (macro) names
Raw symbols instead of keywords
for constant arguments
Requires a macro layer
Example
; ; Be for e :
( document−class : a r t i c l e : paper : l e t t e r : pt 12)
; ; Af t e r :
( documentclass a r t i c l e : paper l e t t e r : p t 12 )
10/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
L
A
T
E
X-like programmatic layer: step 3
Even less full of Lisp idioms
Symbol macros
Turning 0-ary function calls into mere symbols
More non lispy function (macro) names
Example
; ; Be for e :
( ma k e − t i tle )
( table−o f − c o n tents )
; ; Af t e r :
m a k e t i t l e
t a b l e o f c o n t e n t s
11/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
L
A
T
E
X-like programmatic layer: step 4
Getting rid of some with-
*
idioms
A (par) command instead of the with-par macro
And the par symbol macro that goes with it.
Example
; ; Be for e :
( with−par "bla bla bla" )
( with−par "bla bla bla" )
; ; Af t e r :
"bla bla bla" pa r "bla bla bla"
12/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
L
A
T
E
X-like programmatic layer: step 5
Getting rid of some other with-
*
idioms
Standalone sectionning commands
Need to get rid of underlying macros
Require explicit state management
e.g. PDF outline levels
Example
; ; Be for e :
( wi t h −se c t i o n "Title"
"bla bla bla" pa r
"bla bla bla")
; ; Af t e r :
( se c t i o n "Title" )
"bla bla bla" pa r
"bla bla bla"
13/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
L
A
T
E
X-like programmatic layer: step 6
The “empty lines” trick
Replacing par with empty lines in Lisp strings
Requires overriding cl-typesetting’s behavior
But that’s easy (it’s Lisp) !
Example
; ; Be for e :
( se c t i o n "Title" )
"bla bla bla" pa r
"bla bla bla")
; ; Af t e r :
( se c t i o n "Title" )
"bla bla bla
bla bla bla"
14/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
L
A
T
E
X-like programmatic layer: step 7
L
A
T
E
X-like named environments
When impossible to get rid of the macro layer
Syntax extension through (read-time) macro characters
Example
; ; Be for e :
( with−document
"bla bla bla"
"bla bla bla")
; ; Af t e r :
{ begi n document }
"bla bla bla"
"bla bla bla"
{ end document }
15/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
L
A
T
E
X-like textual layer
The ultimate goal
Idea
Remain text-driven instead of program-driven
Convert automatically to the programmatic layer
Implementation
Use \ as an escape (to Lisp) character
Everything else is accumulated into Lisp strings
Example
; ; Be for e :
( se c t i o n "Lorem Ipsum")
"Lorem " ( t e x t bf "ipsum" ) " " ( t e x t i t "dolor" ) " sit amet, ...
;; After:
\(section "Lorem Ipsum")
Lorem \(textbf "ipsum") \(textit "d o l o r ") sit amet, ...
17/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
The merits of extensibility
By example
Rivers detection
Requires introspection (boxes internal representation)
But that’s easy (it’s Lisp, and OO) !
Implementation
New kind of box (subclass of vbox)
Collects content subject to rivers detection
Additional stroking method for this new box
User-level “rivers” environment
19/23
TiCL
Didier Verna
Introduction
Programmatic
Textual
Extensions
Conclusion
Conclusion
Last year: fitness of Lisp for a T
E
X implementation
This year: proof of concept
Remember the objectives ?
A more modern and consistent API
Real programming capabilities
Still simple to use (at least for simple things)
Extensibility / customizability
21/23
