(defpackage #:parse-latex (:use :cl :esrap))

(in-package #:parse-latex)

(defrule a-z (alpha-char-p character))
(defrule alphabet (+ a-z))
(defrule filename-char a-z)

(defrule control-m #\Return)
(defrule control-l #\Page)

(defrule accent-acute "\\'")
(defrule accent-grav "\\`")
(defrule accent-umlaut "\\\"" )
(defrule accent-circumflex "\\^")
(defrule accent (or accent-circumflex accent-grav accent-acute accent-umlaut))

(defrule letter (or a-z #\- accent))
(defrule digit (digit-char-p character))
(defrule number (+ digit))

(defrule math-number (and (* digit) (? ".") number) (:text t))
(defrule text-number (and number (* (and (? ",") math-number))) (:text t))
(defrule time-number (and (+ digit) (? ":") (+ digit)) (:text t))

(defrule alphabet-string (* letter) (:text t))

(defrule horizontal-space (or #\Space #\Tab))
(defrule newline #\Newline)
(defrule whitespace (or newline horizontal-space))
(defrule blank-line (and (* horizontal-space) newline))
(defrule paragraph-separator (and newline (+ blank-line)))

(defun punctuationp (character)
  (find character "-=_^/.,:;!?\"()@\[\]|<>*+'`"))
(defrule punctuation (punctuationp character))
(defrule backslash #\\)
(defun latex-special-char-p (character)
  (find character "&%$#_{}~^\\"))
(defrule latex-special-char (latex-special-char-p character))
(defun math-op-p (character)
  (find character "+*/'<>=-"))
(defrule math-op (math-op-p character))

(defrule pos-tab-arg (and "[" (+ (or #\h #\b #\t #\p)) "]"))
(defrule opt-tab-arg (and "{" (* (or #\l #\r #\c #\|)) "}"))

(defrule begin-env-open (and backslash "begin" (* horizontal-space) "{"))
(defrule begin-env-close (and "}" (* whitespace)))

(defrule begin-display-math "$$")
(defrule end-display-math "$$")