X-Git-Url: https://git.distorted.org.uk/~mdw/lisp/blobdiff_plain/0ff9df03bb54ba792cefa551face51748ae34259..8a2e8de1d736200d9aa751b85d5f97af33b91150:/infix.lisp

diff --git a/infix.lisp b/infix.lisp
index a0d320d..ea78422 100644
--- a/infix.lisp
+++ b/infix.lisp
@@ -34,7 +34,8 @@
 	   #:++ #:--
 	   #:<< #:>>
 	   #:if #:then #:else
-	   #:let #:let* #:in))
+	   #:let #:let* #:in
+	   #:bind))
 
 (defpackage #:infix
   (:use #:common-lisp #:infix-keywords)
@@ -356,9 +357,9 @@
 ;;;--------------------------------------------------------------------------
 ;;; Infrastructure for operator definitions.
 
-(defun delim (delim &key (requiredp t))
+(defun delim (delim &optional (requiredp t))
   "Parse DELIM, and read the next token.  Returns t if the DELIM was found,
-   or nil if not (and requiredp was nil)."
+   or nil if not (and REQUIREDP was nil)."
   (cond ((eq *token* delim) (get-token) t)
 	(requiredp (error "expected `~(~A~)'; found ~S" delim *token*))
 	(t nil)))
@@ -413,7 +414,7 @@
   (let ((stuff nil))
     (loop
       (push (parse-infix 0) stuff)
-      (unless (delim '|,| :requiredp nil)
+      (unless (delim '|,| nil)
 	(return)))
     (nreverse stuff)))
 
@@ -425,7 +426,7 @@
         (error "expected symbol; found ~S" *token*))
       (push *token* stuff)
       (get-token)
-      (unless (delim '|,| :requiredp nil)
+      (unless (delim '|,| nil)
 	(return)))
     (nreverse stuff)))
 
@@ -606,20 +607,22 @@
 
 (defopfunc loop operand
   (get-token)
-  (pushval `(loop ,@(progn (strip-progn (parse-infix 0))))))
-
-(defopfunc multiple-value-bind operand
-  (get-token)
-  (pushval `(multiple-value-bind
-	        ,(parse-ident-list)
-	        ,(progn (delim '=) (parse-infix))
-	      ,@(progn (delim 'in) (strip-progn (parse-infix 0))))))
-
-(defopfunc multiple-value-setq operand
-  (get-token)
-  (pushval `(multiple-value-setq
-	        ,(parse-ident-list)
-	        ,(progn (delim '=) (parse-infix 0)))))
+  (pushval `(loop ,@(strip-progn (parse-infix 0)))))
+
+(defopfunc bind operand
+  (labels ((loop ()
+	    (let ((ids (parse-ident-list))
+		  (valform (progn (delim '=) (parse-infix 0)))
+		  (body (if (delim '|,| nil)
+			    (loop)
+			    (progn
+			      (delim 'in)
+			      (strip-progn (parse-infix 0))))))
+	      (list (if (and ids (null (cdr ids)))
+			`(let ((,(car ids) ,valform)) ,@body)
+			`(multiple-value-bind ,ids ,valform ,@body))))))
+    (get-token)
+    (pushval (car (loop)))))
 
 ;;;--------------------------------------------------------------------------
 ;;; Parsing function bodies and lambda lists.
@@ -648,18 +651,18 @@
 		    (get-token)
 		    (when (eq *token* '|)|)
 		      (go done))
-		    (delim '|,| :requiredp nil)
+		    (delim '|,| nil)
 		    (go loop))
 		   ((symbolp *token*)
 		    (let ((name *token*))
 		      (get-token)
-		      (if (delim '= :requiredp nil)
+		      (if (delim '= nil)
 			  (push (list name (parse-infix 0)) args)
 			  (push name args))))
 		   (t
 		    (push *token* args)
 		    (get-token)))
-	     (when (delim '|,| :requiredp nil)
+	     (when (delim '|,| nil)
 	       (go loop))
 	   done)))
       (delim '|)|)
@@ -667,7 +670,7 @@
 
 (defun parse-func-name ()
   "Parse a function name and return its Lisp equivalent."
-  (cond ((delim '|(| :requiredp nil)
+  (cond ((delim '|(| nil)
 	 (prog1 (parse-infix) (delim '|)|)))
 	(t (prog1 *token* (get-token)))))
 	 
@@ -692,7 +695,7 @@
       (push `(,(parse-func-name) ,(parse-lambda-list)
 	       ,@(strip-progn (parse-infix 0)))
 	    clauses)
-      (unless (delim '|,| :requiredp nil)
+      (unless (delim '|,| nil)
 	(return)))
     (delim 'in)
     (pushval `(,kind ,(nreverse clauses) ,@(strip-progn (parse-infix 0))))))
@@ -714,14 +717,27 @@
       (unless (eq *token* delim)
 	(error "expected ~S; found ~S" delim *token*)))))
 
-(defun install-infix-reader (&optional (char #\$))
-  "Installs a macro character `$ INFIX...  $' for translating infix notation
+(defun install-infix-reader
+    (&optional (start #\{) (end #\}) &key dispatch (readtable *readtable*))
+  "Installs a macro character `{ INFIX... }' for translating infix notation
    to Lisp forms.  You also want to (use-package :infix-keywords) if you do
    this."
-  (let ((delim (intern (string #\$) 'infix-keywords)))
-    (set-macro-character char (lambda (stream ch)
-				(declare (ignore ch))
-				(read-infix stream :delim delim)))))
+  (let ((delim (intern (string end) 'infix-keywords)))
+    (flet ((doit (stream &rest noise)
+	     (declare (ignore noise))
+	     (read-infix stream :delim delim)))
+      (if dispatch
+	  (set-dispatch-macro-character dispatch start #'doit readtable)
+	  (set-macro-character start #'doit nil readtable))
+      (unless (or (eql start end)
+		  (multiple-value-bind
+		      (func nontermp)
+		      (get-macro-character end readtable)
+		    (and func (not nontermp))))
+	(set-macro-character end (lambda (noise)
+				   (declare (ignore noise))
+				   (error "Unexpected `~C'." end))
+			     nil readtable)))))
 
 ;;;--------------------------------------------------------------------------
 ;;; Testing things.
@@ -799,8 +815,14 @@
      (labels ((foo (x) (+ x 1)) (bar (x) (- x 1))) (foo (bar y))))
     ("defun foo (x) x - 6" .
      (defun foo (x) (- x 6)))
-    ("multiple-value-bind x, y, z = values(4, 6, 8) in x + y + z" .
-     (multiple-value-bind (x y z) (values 4 6 8) (+ x y z)))))
+    ("bind x = 3 in x - 2" . (let ((x 3)) (- x 2)))
+    ("bind x, y = values(1, 2),
+           z = 3,
+           docs, decls, body = parse-body(body) in complicated" .
+     (multiple-value-bind (x y) (values 1 2)
+       (let ((z 3))
+	 (multiple-value-bind (docs decls body) (parse-body body)
+	   complicated))))))
 
 ;;;--------------------------------------------------------------------------
 ;;; Debugging guff.