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authorJuan Manuel Tomás <jtomas1815@gmail.com>2022-12-07 02:23:29 -0300
committerJuan Manuel Tomás <jtomas1815@gmail.com>2022-12-07 02:23:29 -0300
commita484c32ae01c697f002e62d17f513155c1151d60 (patch)
tree17f9e9c9a8969815917ec402871b0f399f5c1b4f
parent18b36cc11c208c18422a9327abd52861c165d5d3 (diff)
downloadmonparser-a484c32ae01c697f002e62d17f513155c1151d60.tar.gz
monparser-a484c32ae01c697f002e62d17f513155c1151d60.zip
Expand on alternative parsers and lookahead idea
-rw-r--r--input.lisp10
-rw-r--r--package.lisp12
-rw-r--r--parser.lisp46
3 files changed, 55 insertions, 13 deletions
diff --git a/input.lisp b/input.lisp
index 1900459..2cdfd84 100644
--- a/input.lisp
+++ b/input.lisp
@@ -18,11 +18,21 @@
(input-cursor input)
(+ window-size (input-cursor input))))
+(defun peek-rest (input)
+ (subseq (input-data input)
+ (input-cursor input)
+ (length (input-data input))))
+
(defun advance (input &optional (amount 1))
(let ((new-input (copy-structure input)))
(incf (input-cursor new-input) amount)
new-input))
+(defun advance-to-end (input)
+ (let ((new-input (copy-structure input)))
+ (setf (input-cursor new-input) (length (input-data input)))
+ new-input))
+
(declaim (ftype (function (simple-string) (values input &optional)) from-string))
(defun from-string (str)
(make-input :data str))
diff --git a/package.lisp b/package.lisp
index 8656c7c..45e8266 100644
--- a/package.lisp
+++ b/package.lisp
@@ -6,13 +6,15 @@
(defpackage #:parser
(:use #:cl)
(:export #:run
- #:new
- #:bind
#:fail
#:either
#:unit
+ #:not-unit
+ #:unit-if
+ #:literal
+ #:until-literal
#:comp
#:nothing
- #:zero-or-one
- #:zero-or-more
- #:one-or-more))
+ #:optional
+ #:many
+ #:separated-list))
diff --git a/parser.lisp b/parser.lisp
index 989938b..a92355c 100644
--- a/parser.lisp
+++ b/parser.lisp
@@ -51,7 +51,25 @@
(funcall (car body) input))))
(either-rec (cons first-parser (cons second-parser other-parsers))))))
-(defun unit (&optional (predicate #'characterp))
+(defun unit (predicate)
+ (lambda (input)
+ (if (input::has-data? input)
+ (let ((c (input::peek-1 input)))
+ (if (char= c predicate)
+ (make-parsing :tree c :left (input::advance input))
+ (make-normal-failure :place input :message "Predicate not satisfied.")))
+ (make-normal-failure :place input :message "Reached end of input."))))
+
+(defun not-unit (predicate)
+ (lambda (input)
+ (if (input::has-data? input)
+ (let ((c (input::peek-1 input)))
+ (if (char/= c predicate)
+ (make-parsing :tree c :left (input::advance input))
+ (make-normal-failure :place input :message "Predicate not satisfied.")))
+ (make-normal-failure :place input :message "Reached end of input."))))
+
+(defun unit-if (&optional (predicate #'characterp))
(lambda (input)
(if (input::has-data? input)
(let ((c (input::peek-1 input)))
@@ -60,15 +78,25 @@
(make-normal-failure :place input :message "Predicate not satisfied.")))
(make-normal-failure :place input :message "Reached end of input."))))
-(defun literal (str)
+(defun literal (predicate)
(lambda (input)
- (if (input::has-data? input (length str))
- (let ((c (input::peek-n input (length str))))
- (if (string= str c)
+ (if (input::has-data? input (length predicate))
+ (let ((c (input::peek-n input (length predicate))))
+ (if (string= predicate c)
(make-parsing :tree c :left (input::advance input (length c)))
(make-normal-failure :place input :message "Predicate not satisfied.")))
(make-normal-failure :place input :message "Reached end of input."))))
+(defun until-literal (predicate)
+ (lambda (input)
+ (let ((c (search predicate (input::input-data input) :start2 (input::input-cursor input))))
+ (if c
+ (let ((window (- c (input::input-cursor input))))
+ (if (> window 0)
+ (make-parsing :tree (input::peek-n input window) :left (input::advance input window))
+ (make-failure :place input :message "Predicate not satisfied.")))
+ (make-parsing :tree (input::peek-rest input) :left (input::advance-to-end input))))))
+
(defmacro comp (bindings &body body)
(if (null bindings)
`(new (progn ,@body))
@@ -89,11 +117,13 @@
(xs (optional (many p))))
(cons x xs)))
-(defun separated-list (p separator)
+(defun separated-list (p separator &key (include-separator nil))
(comp ((v p)
- (sep (optional (the-char separator)))
+ (sep (optional separator))
(vn (if sep
(either (separated-list p separator)
(fail "Value expected."))
nothing)))
- (cons v vn)))
+ (if include-separator
+ (cons v (cons sep vn))
+ (cons v vn))))