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;;; lout.scm -- Lout implementation of the `eq' package.
;;;
;;; Copyright 2005, 2006, 2007, 2008, 2010 Ludovic Court�s <ludo@gnu.org>
;;;
;;;
;;; This file is part of Skribilo.
;;;
;;; Skribilo is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation, either version 3 of the License, or
;;; (at your option) any later version.
;;;
;;; Skribilo is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with Skribilo. If not, see <http://www.gnu.org/licenses/>.
(define-module (skribilo package eq lout)
#:use-module (skribilo package eq)
#:use-module (skribilo ast)
#:autoload (skribilo output) (output)
#:use-module (skribilo writer)
#:use-module (skribilo engine)
#:use-module (skribilo lib)
#:use-module (skribilo utils syntax)
#:use-module (srfi srfi-1))
(skribilo-module-syntax)
;;;
;;; Initialization.
;;;
(let ((lout (find-engine 'lout)))
(if (not lout)
(skribe-error 'eq "Lout engine not found" lout)
(let ((includes (engine-custom lout 'includes)))
;; Append the `eq' include file
(engine-custom-set! lout 'includes
(string-append includes "\n"
"@SysInclude { "
(if (*use-lout-math?*) "math" "eq")
" }\n")))))
;;;
;;; Simple markup writers.
;;;
(markup-writer 'eq-display (find-engine 'lout)
:before "\n@BeginAlignedDisplays\n"
:after "\n@EndAlignedDisplays\n")
(markup-writer 'eq (find-engine 'lout)
:options '(:inline? :align-with :div-style :mul-style :number)
:before (lambda (node engine)
(let ((displayed? (case (markup-option node :inline?)
((auto) (is-markup? (ast-parent node)
'eq-display))
(else (not (markup-option node :inline?)))))
(number (equation-number-string node)))
;; Note: The `@BypassNumber' option appeared in Lout 3.36.
(if (and displayed? (not (*embedded-renderer*)))
(display (if (string? number)
(string-append "@CAND @BypassNumber { \""
number "\" } ")
"@CAD ")))
(display "{ ")))
:action (lambda (node engine)
(display (if (inline-equation? node)
(if (*use-lout-math?*)
"@M { "
"@OneRow @OneCol @E { ")
(if (*use-lout-math?*)
"@Math { "
"@Eq { ")))
(let ((eq (markup-body node)))
;;(fprint (current-error-port) "eq=" eq)
(output eq engine)))
:after " } }")
;; Scaled parenthesis.
;;
;; * We could use `pmatrix' here but it precludes line-breaking within
;; equations, so we use our own variant.
;;
;; * The use of `strut @Font' aims to produce balanced parentheses,
;; regardless of the ascender/descender of the numerator/denominator, so
;; that, e.g., "(a/b)" has parentheses similar to "(b/a)".
;;
(define %left-paren
"{ { Base \"nostrut\" } @Font @VScale \"(\" } \"strut\" @Font { ")
(define %right-paren
" }{ { Base \"nostrut\" } @Font @VScale \")\" }")
(define (div-style->lout style)
(case style
((over) "over")
((fraction) "frac")
((div) "div")
((slash) "slash")
(else
(error "unsupported div style" style))))
(define (mul-style->lout style)
(case style
((space) "")
((cross) "times")
((asterisk) "*")
((dot) "cdot")
(else
(error "unsupported mul style" style))))
(define (simple-lout-markup-writer sym . args)
(let* ((lout-name (if (null? args)
(symbol->string sym)
(car args)))
(parentheses? (if (or (null? args) (null? (cdr args)))
#t
(cadr args)))
(precedence (operator-precedence sym)))
(markup-writer (symbol-append 'eq: sym) (find-engine 'lout)
:action (lambda (node engine)
(let* ((lout-name (if (string? lout-name)
lout-name
(lout-name node engine)))
(eq (ast-parent node))
(eq-parent (ast-parent eq)))
(let loop ((operands (markup-body node))
(first? #t))
(if (null? operands)
#t
(let* ((align?
(and first?
(is-markup? eq-parent 'eq-display)
(eq? sym
(markup-option eq :align-with))
(direct-equation-child? node)))
(op (car operands))
(eq-op? (equation-markup? op))
(need-paren?
(and parentheses? eq-op?
(>= (operator-precedence
(equation-markup-name->operator
(markup-markup op)))
precedence)))
(open-par (if need-paren? %left-paren ""))
(close-par (if need-paren? %right-paren ""))
(column (port-column (current-output-port))))
;; Work around Lout's limitations...
(if (> column 1000) (newline))
(display (string-append " { " open-par))
(output op engine)
(display (string-append close-par " }"))
(if (pair? (cdr operands))
(display (string-append " "
(if align? "^" "")
lout-name
" ")))
(loop (cdr operands) #f)))))))))
;; `+' and `*' have higher precedence than `-', `/', `=', etc., so their
;; operands do not need to be enclosed in parentheses. OTOH, since we use a
;; horizontal bar of `/', we don't need to parenthesize its arguments.
(simple-lout-markup-writer '+)
(simple-lout-markup-writer '- "-")
(simple-lout-markup-writer '*
(lambda (n e)
;; Obey either the per-node `:mul-style' or the
;; top-level one.
(mul-style->lout
(or (markup-option n :mul-style)
(let ((eq (ast-parent n)))
(markup-option eq :mul-style))))))
(simple-lout-markup-writer '/
(lambda (n e)
;; Obey either the per-node `:div-style' or the
;; top-level one.
(div-style->lout
(or (markup-option n :div-style)
(let ((eq (ast-parent n)))
(markup-option eq :div-style)))))
#f)
(simple-lout-markup-writer 'modulo "mod")
(simple-lout-markup-writer '=)
(simple-lout-markup-writer '<)
(simple-lout-markup-writer '>)
(simple-lout-markup-writer '<=)
(simple-lout-markup-writer '>=)
(define (binary-lout-markup-writer sym lout-name)
(markup-writer (symbol-append 'eq: sym) (find-engine 'lout)
:action (lambda (node engine)
(let ((body (markup-body node)))
(if (= (length body) 2)
(let* ((first (car body))
(second (cadr body))
(parentheses? (and (equation-markup? first)
(not
(memq (markup-markup first)
'(eq:combinations))))))
(display " { { ")
(if parentheses? (display %left-paren))
(output first engine)
(if parentheses? (display %right-paren))
(display (string-append " } " lout-name " { "))
(output second engine)
(display " } } "))
(skribe-error (symbol-append 'eq: sym)
"wrong number of arguments"
body))))))
(binary-lout-markup-writer 'expt "sup")
(binary-lout-markup-writer 'in "in")
(binary-lout-markup-writer 'notin "notin")
(markup-writer 'eq:apply (find-engine 'lout)
:action (lambda (node engine)
(let ((func (car (markup-body node))))
(output func engine)
(display %left-paren)
(let loop ((operands (cdr (markup-body node))))
(if (null? operands)
#t
(begin
(output (car operands) engine)
(if (not (null? (cdr operands)))
(display ", "))
(loop (cdr operands)))))
(display %right-paren))))
(markup-writer 'eq:limit (find-engine 'lout)
:action (lambda (node engine)
(let ((body (markup-body node))
(var (markup-option node :var))
(limit (markup-option node :limit)))
(format #t "{ lim ~a { { "
(if (*use-lout-math?*)
"atop @SubScriptStyle"
"from"))
(output var engine)
(display " } --> ")
(output limit engine)
(display (string-append " } } @VContract { " %left-paren))
(output body engine)
(display (string-append %right-paren " } ")))))
(markup-writer 'eq:combinations (find-engine 'lout)
:action (lambda (node engine)
(let ((of (markup-option node :of))
(among (markup-option node :among)))
;; Note: The `matrix' is enclosed in `nostrut' so that its
;; brackets are not affected. It also looks better to enclose
;; the matrix contents in `nostrut'.
(display " ` { \"nostrut\" @Font ")
(display "matrix atleft { lpar } atright { rpar } { ")
(display "row col { ")
(output of engine)
(display " } row col { ")
(output among engine)
(display " } } } `\n"))))
;;;
;;; Sums, products, integrals, etc.
;;;
(define (range-lout-markup-writer sym lout-name)
(markup-writer (symbol-append 'eq: sym) (find-engine 'lout)
:action (lambda (node engine)
(let ((from (markup-option node :from))
(to (markup-option node :to))
(body (markup-body node)))
(display (string-append " { "
(if (*use-lout-math?*)
""
"big ")
lout-name
" from { "))
(output from engine)
(display " } to { ")
(output to engine)
(display " } { ")
(output body engine)
(display " } } ")))))
(range-lout-markup-writer 'sum "sum")
(range-lout-markup-writer 'product "prod")
(markup-writer 'eq:script (find-engine 'lout)
:action (lambda (node engine)
(let ((body (markup-body node))
(sup (markup-option node :sup))
(sub (markup-option node :sub)))
(display " { { ")
(output body engine)
(display " } ")
(if sup
(begin
(display (if sub " supp { " " sup { "))
(output sup engine)
(display " } ")))
(if sub
(begin
(display (if sup " on { " " sub { "))
(output sub engine)
(display " } ")))
(display " } "))))
;;;
;;; Sets.
;;;
(markup-writer 'eq:set (find-engine 'lout)
;; Take the elements of the set and enclose them into braces.
:action (lambda (node engine)
(define (printable elem)
(if (eq? elem '...)
(symbol "ellipsis")
elem))
(display " brmatrix { ")
(pair-for-each (lambda (pair)
(let ((elem (printable (car pair))))
(output elem engine)
(if (not (null? (cdr pair)))
(output ", " engine))))
(markup-body node))
(display " } ")))
;;; arch-tag: 2a1410e5-977e-4600-b781-3d57f4409b35
|
