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Diffstat (limited to 'par/piece-table.scm')
| -rw-r--r-- | par/piece-table.scm | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/par/piece-table.scm b/par/piece-table.scm index 24608e3..21661e7 100644 --- a/par/piece-table.scm +++ b/par/piece-table.scm @@ -185,6 +185,35 @@ (define (piece-table-text-length piece-table) (reduce + 0 (map piece-length (piece-table-pieces piece-table)))) +(define (piece-table-for-each piece-table f from to) + ;; TODO: default from and to + "Calls `f` through the characters of the piece-table, like `string-for-each` + would do, but the `f` call also includes the piece (to expose extra data) and + the index of the character" + (let loop ((idx 0) + (start 0) + (pieces (piece-table-pieces piece-table))) + (let* ((piece (car pieces)) + (len (piece-length piece)) + (end (+ start len)) + (more? (not (null? (cdr pieces))))) + (when (< idx to) ;; Skip tail + (if (or (= idx end) (<= end from)) + ;; Current piece doesn't contain the section we need or finished + ;; Jump to next piece + (when more? (loop end end (cdr pieces))) + ;; Current piece contains part of the section we need, go char by + ;; char + (begin + (when (<= from idx) + (f + (string-ref (buffer->string (piece-buffer piece)) + (+ (piece-start piece) (- idx start))) + idx + piece)) + ;; There are chars to process in this piece + (loop (+ idx 1) start pieces))))))) + (define (piece-table-find-line-break piece-table idx) (let loop ((idx 0) (ps (piece-table-pieces piece-table)) |