diff options
| author | Leah Neukirchen <leah@vuxu.org> | 2022-10-31 23:12:31 +0100 |
|---|---|---|
| committer | Leah Neukirchen <leah@vuxu.org> | 2022-10-31 23:12:31 +0100 |
| commit | 78ec49d84418aa10c25cc418a8818518b6fa307f (patch) | |
| tree | 8b9298c3fdd547c7bd045440309036a5799a2bfe | |
| parent | 7f98ae1710bfd34d9111f8e8d7e6b358590fec3a (diff) | |
| download | mew-78ec49d84418aa10c25cc418a8818518b6fa307f.tar.gz mew-78ec49d84418aa10c25cc418a8818518b6fa307f.tar.xz mew-78ec49d84418aa10c25cc418a8818518b6fa307f.zip | |
add uniq-accumulator
| -rw-r--r-- | mew.scm | 11 | ||||
| -rw-r--r-- | mew.svnwiki | 6 |
2 files changed, 16 insertions, 1 deletions
diff --git a/mew.scm b/mew.scm index edb14bc..bab917c 100644 --- a/mew.scm +++ b/mew.scm @@ -18,7 +18,7 @@ sing? set str slurp tally-accumulator tbl time while - unlist until + uniq-accumulator unlist until vals -> fun-> fun->> set-> <>? @@ -611,6 +611,15 @@ groups (hash-table-update!/default groups (f x) (op cons x _) '()))))) + (define uniq-accumulator + (case-lambda + (() (uniq-accumulator (op))) + ((f) (let ((items (tbl))) + (lambda (x) + (if (eof-object? x) + (hash-table-values items) + (hash-table-update!/default items (f x) identity x))))))) + (define-syntax one-of (er-macro-transformer (lambda (expr rename compare) diff --git a/mew.svnwiki b/mew.svnwiki index 9a75f5b..2829c5b 100644 --- a/mew.svnwiki +++ b/mew.svnwiki @@ -316,6 +316,12 @@ numbers. Returns an accumulator that stores all elements in lists in a hash-table, applying {{<f>}} to the element to compute the key. +<procedure>(uniq-accumulator <f>?)</procedure> + +Returns an accumulator that returns a list of unique elements. +Two elements are considered equal if their image under {{<f>}} is {{equal?}}. +{{<f>}} defaults to the identity function. + <procedure>(inject <f> <init>?)</procedure> Returns a procedure that takes an generator (or something convertible |