altos/lisp: More schemisms

Add 'if'.
setq -> set!, but doesn't define new variables
def -> define
Add pair? and list?
Add eq? and eqv? as aliases for =

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 61 insertions, 26 deletions

diff --git a/src/lisp/ao_lisp_const.lisp b/src/lisp/ao_lisp_const.lisp
index df277fce..37307a68 100644
--- a/src/lisp/ao_lisp_const.lisp
+++ b/src/lisp/ao_lisp_const.lisp
@@ -23,17 +23,17 @@
 					; having lots of output generated
 					;
 
-(setq def (macro (name val rest)
-		 (list
-		  'progn
-		  (list
-		   'set
-		   (list 'quote name)
-		   val)
-		  (list 'quote name)
-		  )
-		 )
-      )
+(set (quote define) (macro (name val rest)
+			(list
+			 'progn
+			 (list
+			  'set
+			  (list 'quote name)
+			  val)
+			 (list 'quote name)
+			 )
+			)
+     )
 
 					;
 					; A slightly more convenient form
@@ -42,9 +42,9 @@
 					; (defun <name> (<params>) s-exprs)
 					;
 
-(def defun (macro (name args exprs)
+(define defun (macro (name args exprs)
 		  (list
-		   def
+		   define
 		   name
 		   (cons 'lambda (cons args exprs))
 		   )
@@ -69,6 +69,28 @@
 (defun 1+ (x) (+ x 1))
 (defun 1- (x) (- x 1))
 
+(define if (macro (test args)
+	       (cond ((null? (cdr args))
+		      (list
+		       cond
+		       (list test (car args)))
+		      )
+		     (else
+		      (list
+		       cond
+		       (list test (car args))
+		       (list 'else (cadr args))
+		       )
+		      )
+		     )
+	       )
+     )
+
+(if (> 3 2) 'yes)
+(if (> 3 2) 'yes 'no)
+(if (> 2 3) 'no 'yes)
+(if (> 2 3) 'no)
+
 					; define a set of local
 					; variables and then evaluate
 					; a list of sexprs
@@ -85,16 +107,16 @@
 					;
 					; e.g.
 					;
-					; (let ((x 1) (y)) (setq y (+ x 1)) y)
+					; (let ((x 1) (y)) (set! y (+ x 1)) y)
 
-(def let (macro (vars exprs)
+(define let (macro (vars exprs)
 		((lambda (make-names make-exprs make-nils)
 
 					;
 					; make the list of names in the let
 					;
 
-		   (setq make-names (lambda (vars)
+		   (set! make-names (lambda (vars)
 				      (cond ((not (null? vars))
 					     (cons (car (car vars))
 						   (make-names (cdr vars))))
@@ -107,7 +129,7 @@
 					; pre-pended to the
 					; expressions to evaluate
 
-		   (setq make-exprs (lambda (vars exprs)
+		   (set! make-exprs (lambda (vars exprs)
 				      (cond ((not (null? vars)) (cons
 						   (list set
 							 (list quote
@@ -126,7 +148,7 @@
 					; the parameters to the lambda is a list
 					; of nils of the right length
 
-		   (setq make-nils (lambda (vars)
+		   (set! make-nils (lambda (vars)
 				     (cond ((not (null? vars)) (cons () (make-nils (cdr vars))))
 					   )
 				     )
@@ -134,7 +156,7 @@
 					; prepend the set operations
 					; to the expressions
 
-		   (setq exprs (make-exprs vars exprs))
+		   (set! exprs (make-exprs vars exprs))
 
 					; build the lambda.
 
@@ -153,11 +175,11 @@
 
 					; boolean operators
 
-(def or (lexpr (l)
+(define or (lexpr (l)
 	       (let ((ret #f))
 		 (while (not (null? l))
-		   (cond ((car l) (setq ret #t) (setq l ()))
-			 ((setq l (cdr l)))))
+		   (cond ((car l) (set! ret #t) (set! l ()))
+			 ((set! l (cdr l)))))
 		 ret
 		 )
 	       )
@@ -167,14 +189,14 @@
 
 (or #f #t)
 
-(def and (lexpr (l)
+(define and (lexpr (l)
 	       (let ((ret #t))
 		 (while (not (null? l))
 		   (cond ((car l)
-			  (setq l (cdr l)))
+			  (set! l (cdr l)))
 			 (#t
-			  (setq ret #f)
-			  (setq l ()))
+			  (set! ret #f)
+			  (set! l ()))
 			 )
 		   )
 		 ret
@@ -185,3 +207,16 @@
 					; execute to resolve macros
 
 (and #t #f)
+
+(defun equal? (a b)
+  (cond ((eq? a b) #t)
+	((and (pair? a) (pair? b))
+	 (and (equal? (car a) (car b))
+	      (equal? (cdr a) (cdr b)))
+	 )
+	(else #f)
+	)
+  )
+
+(equal? '(a b c) '(a b c))
+(equal? '(a b c) '(a b b))