From cfdeba05bd54e09f9fe90ca00c780c8a6cfd565d Mon Sep 17 00:00:00 2001
From: Ekaitz Zarraga <ekaitz@elenq.tech>
Date: Wed, 14 Feb 2024 00:50:31 +0100
Subject: par: move buffers to separate file
---
par/buffers.scm | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
par/buffers.sld | 12 ++++++++++++
par/piece-table.scm | 50 --------------------------------------------------
par/piece-table.sld | 1 +
4 files changed, 63 insertions(+), 50 deletions(-)
create mode 100644 par/buffers.scm
create mode 100644 par/buffers.sld
diff --git a/par/buffers.scm b/par/buffers.scm
new file mode 100644
index 0000000..2a2028e
--- /dev/null
+++ b/par/buffers.scm
@@ -0,0 +1,50 @@
+;; INTERNAL BUFFERS: The indirection level of the buffer records is cool, so we
+;; can resize the underlying strings and keep all the pieces untouched and
+;; pointing to the correct thing.
+
+;; There's nothing preventing the programmer from writing in the ro-buffer...
+;; but it will be hidden under the piece-table interface so nothing should
+;; happen
+(define-record-type <ro-buffer>
+ (make-ro-buffer string)
+ ro-buffer?
+ (string ro-buffer-string))
+
+;; This is where things are added, it's able to grow to handle new additions
+(define-record-type <add-buffer>
+ (%make-add-buffer string used)
+ add-buffer?
+ (string add-buffer-string set-add-buffer-string!)
+ (used add-buffer-used set-add-buffer-used!))
+
+;; TODO think about a way to make all this polymorphism automagic
+(define (buffer->string buffer)
+ "Returns the underlying string of the buffer"
+ (cond
+ ((add-buffer? buffer) (add-buffer-string buffer))
+ ((ro-buffer? buffer) (ro-buffer-string buffer))))
+;;
+
+(define add-buffer-length (make-parameter 100))
+
+(define (make-add-buffer)
+ (%make-add-buffer (make-string (add-buffer-length)) 0))
+
+(define (enlarge-add-buffer! add-buffer at-least)
+ (let* ((str (add-buffer-string add-buffer))
+ (len (string-length str))
+ ; TODO: Better algo here?
+ (new (make-string (+ len at-least (add-buffer-length)))))
+ (set-add-buffer-string! add-buffer new)
+ (string-copy! new 0 str)))
+
+(define (add-buffer-append! add-buffer str)
+ "Appends to add buffer, growing if necessary"
+ (let ((append-len (string-length str))
+ (buffer-used (add-buffer-used add-buffer))
+ (buffer-size (string-length (add-buffer-string add-buffer))))
+ (when (>= (+ append-len buffer-used) buffer-size)
+ (enlarge-add-buffer! add-buffer append-len))
+ (string-copy! (add-buffer-string add-buffer) buffer-used str)
+ (set-add-buffer-used! add-buffer (+ append-len buffer-used))))
+
diff --git a/par/buffers.sld b/par/buffers.sld
new file mode 100644
index 0000000..86f07d8
--- /dev/null
+++ b/par/buffers.sld
@@ -0,0 +1,12 @@
+(define-library (par buffers)
+ (import (scheme base)
+ (srfi 11))
+ (export buffer->string
+
+ make-ro-buffer
+ make-add-buffer
+
+ add-buffer-used
+ add-buffer-length
+ add-buffer-append!)
+ (include "buffers.scm"))
diff --git a/par/piece-table.scm b/par/piece-table.scm
index c1688a2..8e6fa82 100644
--- a/par/piece-table.scm
+++ b/par/piece-table.scm
@@ -127,56 +127,6 @@
-;; INTERNAL BUFFERS: The indirection level of the buffer records is cool, so we
-;; can resize the underlying strings and keep all the pieces untouched and
-;; pointing to the correct thing.
-
-;; There's nothing preventing the programmer from writing in the ro-buffer...
-;; but it will be hidden under the piece-table interface so nothing should
-;; happen
-(define-record-type <ro-buffer>
- (make-ro-buffer string)
- ro-buffer?
- (string ro-buffer-string))
-
-;; This is where things are added, it's able to grow to handle new additions
-(define-record-type <add-buffer>
- (%make-add-buffer string used)
- add-buffer?
- (string add-buffer-string set-add-buffer-string!)
- (used add-buffer-used set-add-buffer-used!))
-
-;; TODO think about a way to make all this polymorphism automagic
-(define (buffer->string buffer)
- "Returns the underlying string of the buffer"
- (cond
- ((add-buffer? buffer) (add-buffer-string buffer))
- ((ro-buffer? buffer) (ro-buffer-string buffer))))
-;;
-
-(define add-buffer-length (make-parameter 100))
-
-(define (make-add-buffer)
- (%make-add-buffer (make-string (add-buffer-length)) 0))
-
-(define (enlarge-add-buffer! add-buffer at-least)
- (let* ((str (add-buffer-string add-buffer))
- (len (string-length str))
- ; TODO: Better algo here?
- (new (make-string (+ len at-least (add-buffer-length)))))
- (set-add-buffer-string! add-buffer new)
- (string-copy! new 0 str)))
-
-(define (add-buffer-append! add-buffer str)
- "Appends to add buffer, growing if necessary"
- (let ((append-len (string-length str))
- (buffer-used (add-buffer-used add-buffer))
- (buffer-size (string-length (add-buffer-string add-buffer))))
- (when (>= (+ append-len buffer-used) buffer-size)
- (enlarge-add-buffer! add-buffer append-len))
- (string-copy! (add-buffer-string add-buffer) buffer-used str)
- (set-add-buffer-used! add-buffer (+ append-len buffer-used))))
-
;; The piece table itself;
diff --git a/par/piece-table.sld b/par/piece-table.sld
index 7209baf..18556d2 100644
--- a/par/piece-table.sld
+++ b/par/piece-table.sld
@@ -1,5 +1,6 @@
(define-library (par piece-table)
(import (scheme base)
+ (par buffers)
(srfi 11))
(export make-piece-table
piece-table-index
--
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