tisp

commit b5f18b6adc4966f26e522dc677cdd684c46ad24e
parent efdb67a929094626d7362fd109f5988ee37ba58c
Author: Ed van Bruggen <edvb@uw.edu>
Date:   Sun, 29 Dec 2019 01:32:08 -0800

Add list filter function

Diffstat:
test.c
 | 
23
++++++++++++-----------
tibs/lib.tsp
 | 
6
++++++

2 files changed, 18 insertions(+), 11 deletions(-)
diff --git a/test.c b/test.c
@@ -262,17 +262,18 @@ char *tests[][2] = {
 	{ "(count 3.2 nil)",                        "0"     },
 	{ "(count \"Bobandy\" '(1/2 1/4 \"Jim\"))", "0"     },
 
-	{ "apply",                     NULL          },
-	{ "(apply list '(1 2 3))",     "(1 2 3)"     },
-	{ "(apply + '(2 90))",         "92"          },
-	{ "(apply list '(a b c d e))", "(a b c d e)" },
-
-	{ "map",                                                    NULL               },
-	{ "(map car '((1 a) (2 b) (3 c)))",                         "(1 2 3)"          },
-	{ "(map cdr '((1 a) (2 b) (3 c)))",                         "((a) (b) (c))"    },
-	{ "(map (lambda (x) (car (cdr x))) '((1 a) (2 b) (3 c)))",  "(a b c)"          },
-	{ "(map cadr '((1/2 .5) (\"conky\" .25) ('bubbles .125)))", "(0.5 0.25 0.125)" },
-	{ "(map inc (list 2 4 8 (^ 2 4)))",                         "(3 5 9 17)"       },
+	{ "list proc",                                              NULL                },
+	{ "(apply list '(1 2 3))",                                  "(1 2 3)"           },
+	{ "(apply + '(2 90))",                                      "92"                },
+	{ "(apply list '(a b c d e))",                              "(a b c d e)"       },
+	{ "(map car '((1 a) (2 b) (3 c)))",                         "(1 2 3)"           },
+	{ "(map cdr '((1 a) (2 b) (3 c)))",                         "((a) (b) (c))"     },
+	{ "(map (lambda (x) (car (cdr x))) '((1 a) (2 b) (3 c)))",  "(a b c)"           },
+	{ "(map cadr '((1/2 .5) (\"conky\" .25) ('bubbles .125)))", "(0.5 0.25 0.125)"  },
+	{ "(map inc (list 2 4 8 (^ 2 4)))",                         "(3 5 9 17)"        },
+	{ "(filter positive? '(1 2 -4 5 -9 10))",                   "(1 2 5 10)"        },
+	{ "(filter odd? '(8 6 17 9 82 34 27))",                     "(17 9 27)"         },
+	{ "(filter integer? '(1/2 3.e-2 9/3 3.2 0.0 8 17))",        "(3 8 17)"          },
 
 	{ "list mod",                                 NULL                        },
 	{ "(reverse '(1 2 3 4 5))",                   "(5 4 3 2 1)"               },
diff --git a/tibs/lib.tsp b/tibs/lib.tsp
@@ -147,6 +147,12 @@
           (map proc (cdr lst)))
     nil))
 
+(define (filter proc lst)
+  (cond
+    ((not (pair? lst)) nil)
+    ((proc (car lst)) (cons (car lst) (filter proc (cdr lst))))
+    (else (filter proc (cdr lst)))))
+
 (define (reverse l)
   (recur f ((in l) (out nil))
          (if (pair? in)