hare

commit 678e4f644cfd39043150f015ac7339d0d7555800
parent 599f127d5a2470a1382afa4d968d1ccbe6a3dc1c
Author: Armin Preiml <apreiml@strohwolke.at>
Date:   Thu, 28 Sep 2023 07:58:08 +0200

bufio::scanner: implement io::reader

Diffstat:
M
bufio/scanner.ha
 | 
27
+++++++++++++++++++++++++++
M
bufio/scanner_test+test.ha
 | 
12
++++++++++++

2 files changed, 39 insertions(+), 0 deletions(-)
diff --git a/bufio/scanner.ha b/bufio/scanner.ha
@@ -11,7 +11,13 @@ use types;
 
 def BUFSZ: size = 4096;
 
+const scanner_vtable = io::vtable {
+	reader = &scan_read,
+	...
+};
+
 export type scanner = struct {
+	stream: io::stream,
 	src: io::handle,
 	buffer: []u8,
 	// Number of bytes available in buffer
@@ -31,6 +37,7 @@ export type scanner = struct {
 // reached.
 export fn newscanner(src: io::handle, maxread: size) scanner = {
 	return scanner {
+		stream = &scanner_vtable,
 		src = src,
 		buffer = alloc([0...], BUFSZ),
 		maxread = maxread,
@@ -45,6 +52,7 @@ export fn newscanner(src: io::handle, maxread: size) scanner = {
 // they wish to free the underlying buffer through bufio.
 export fn newscanner_static(src: io::handle, buffer: []u8) scanner = {
 	return scanner {
+		stream = &scanner_vtable,
 		src = src,
 		buffer = buffer,
 		maxread = len(buffer),
@@ -59,6 +67,25 @@ export fn finish(scan: *scanner) void = {
 	free(scan.buffer);
 };
 
+fn scan_read(s: *io::stream, buf: []u8) (size | io::EOF | io::error) = {
+	let scan = s: *scanner;
+	if (scan.pending == 0) {
+		match (scan_readahead(scan)?) {
+		case io::EOF =>
+			return io::EOF;
+		case size =>
+			yield;
+		};
+	};
+
+	// Consume previous read, if any
+	scan_shift(scan);
+
+	const n = if (len(buf) > scan.pending) scan.pending else len(buf);
+	buf[..n] = scan_consume(scan, n)[..];
+	return n;
+};
+
 // Fills up the scanner buffer with data from the underlying I/O handle. If no
 // space remains in the read buffer, it is expanded by BUFSZ (up to maxread).
 // Then, one read from the underlying I/O handle is performed and scan.pending
diff --git a/bufio/scanner_test+test.ha b/bufio/scanner_test+test.ha
@@ -111,3 +111,15 @@ use strings;
 		};
 	};
 };
+
+@test fn scan_read() void = {
+	const expected: [_]u8 = [
+		0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b,
+	];
+	let in = memio::fixed(expected);
+
+	let scanner = newscanner(&in, 2);
+	let result = io::drain(&scanner)!;
+	defer free(result);
+	assert(bytes::equal(expected, result));
+};