diff options
| -rw-r--r-- | ccwl/ccwl.scm | 2 | ||||
| -rw-r--r-- | ccwl/utils.scm | 28 | ||||
| -rw-r--r-- | tests/utils.scm | 14 |
3 files changed, 32 insertions, 12 deletions
diff --git a/ccwl/ccwl.scm b/ccwl/ccwl.scm index 4480314..8f02b0c 100644 --- a/ccwl/ccwl.scm +++ b/ccwl/ccwl.scm @@ -743,7 +743,7 @@ represented by <step> objects." (list))) ;; tee ((tee expressions ...) - (let ((key-lists step-lists (mapn (cut collect-steps <> input-keys) + (let ((key-lists step-lists (map2 (cut collect-steps <> input-keys) #'(expressions ...)))) (values ;; Global workflow input keys may be duplicated across the diff --git a/ccwl/utils.scm b/ccwl/utils.scm index 3c18efd..2abc404 100644 --- a/ccwl/utils.scm +++ b/ccwl/utils.scm @@ -1,5 +1,5 @@ ;;; ccwl --- Concise Common Workflow Language -;;; Copyright © 2021, 2022, 2023 Arun Isaac <arunisaac@systemreboot.net> +;;; Copyright © 2021, 2022, 2023, 2025 Arun Isaac <arunisaac@systemreboot.net> ;;; ;;; This file is part of ccwl. ;;; @@ -39,6 +39,7 @@ lambda** syntax-lambda** mapn + map2 foldn filter-mapi)) @@ -311,22 +312,31 @@ element. For example, lst (iota (length lst)))) -(define (mapn proc lst) +(define (mapn proc lst n) "Map the procedure PROC over list LST and return a list containing -the results. PROC can return multiple values, in which case, an equal -number of lists are returned. For example, +the results. PROC must return N values, in which case, N lists are +returned. For example, (mapn (lambda (n) (values (expt n 2) (expt n 3))) - (iota 5)) + (iota 5) + 2) => (0 1 4 9 16) => (0 1 8 27 64)" (apply values - (apply zip - (map (lambda (x) - (call-with-values (cut proc x) list)) - lst)))) + (match lst + ;; With an empty list, we cannot know the number of values + ;; proc would return. Hence this special case. + (() (make-list n '())) + (_ + (apply zip + (map (lambda (x) + (call-with-values (cut proc x) list)) + lst)))))) + +(define map2 + (cut mapn <> <> 2)) (define (foldn proc lst . inits) "Apply PROC to the elements of LST to build a result, and return diff --git a/tests/utils.scm b/tests/utils.scm index 50c3396..d786d02 100644 --- a/tests/utils.scm +++ b/tests/utils.scm @@ -1,5 +1,5 @@ ;;; ccwl --- Concise Common Workflow Language -;;; Copyright © 2021, 2022, 2023 Arun Isaac <arunisaac@systemreboot.net> +;;; Copyright © 2021, 2022, 2023, 2025 Arun Isaac <arunisaac@systemreboot.net> ;;; ;;; This file is part of ccwl. ;;; @@ -194,7 +194,17 @@ (let ((squares cubes (mapn (lambda (n) (values (expt n 2) (expt n 3))) - (iota 5)))) + (iota 5) + 2))) + (list squares cubes))) + +(test-equal "mapn on an empty list" + '(() ()) + (let ((squares cubes (mapn (lambda (n) + (values (expt n 2) + (expt n 3))) + '() + 2))) (list squares cubes))) (test-equal "foldn" |