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-rw-r--r--std/examples/tests/xeval_test.ts4
-rw-r--r--std/examples/xeval.ts104
-rw-r--r--std/io/bufio.ts99
-rw-r--r--std/io/bufio_test.ts29
4 files changed, 138 insertions, 98 deletions
diff --git a/std/examples/tests/xeval_test.ts b/std/examples/tests/xeval_test.ts
index bfd66c097..3df11c8af 100644
--- a/std/examples/tests/xeval_test.ts
+++ b/std/examples/tests/xeval_test.ts
@@ -27,7 +27,7 @@ const xevalPath = "examples/xeval.ts";
Deno.test(async function xevalCliReplvar(): Promise<void> {
const p = run({
- args: [execPath(), xevalPath, "--", "--replvar=abc", "console.log(abc)"],
+ args: [execPath(), xevalPath, "--replvar=abc", "console.log(abc)"],
stdin: "piped",
stdout: "piped",
stderr: "null"
@@ -41,7 +41,7 @@ Deno.test(async function xevalCliReplvar(): Promise<void> {
Deno.test(async function xevalCliSyntaxError(): Promise<void> {
const p = run({
- args: [execPath(), xevalPath, "--", "("],
+ args: [execPath(), xevalPath, "("],
stdin: "null",
stdout: "piped",
stderr: "piped"
diff --git a/std/examples/xeval.ts b/std/examples/xeval.ts
index 75c864745..16ce37fb4 100644
--- a/std/examples/xeval.ts
+++ b/std/examples/xeval.ts
@@ -1,5 +1,6 @@
import { parse } from "../flags/mod.ts";
-const { Buffer, EOF, args, exit, stdin, writeAll } = Deno;
+import { readStringDelim } from "../io/bufio.ts";
+const { args, exit, stdin } = Deno;
type Reader = Deno.Reader;
/* eslint-disable-next-line max-len */
@@ -10,18 +11,16 @@ const AsyncFunction = Object.getPrototypeOf(async function(): Promise<void> {})
/* eslint-disable max-len */
const HELP_MSG = `xeval
-Eval a script on lines from stdin.
-Read from standard input and eval code on each whitespace-delimited
-string chunks.
+Run a script for each new-line or otherwise delimited chunk of standard input.
Print all the usernames in /etc/passwd:
- cat /etc/passwd | deno -A https://deno.land/std/examples/xeval.ts -- "a = $.split(':'); if (a) console.log(a[0])"
+ cat /etc/passwd | deno -A https://deno.land/std/examples/xeval.ts "a = $.split(':'); if (a) console.log(a[0])"
A complicated way to print the current git branch:
- git branch | deno -A https://deno.land/std/examples/xeval.ts -- -I 'line' "if (line.startsWith('*')) console.log(line.slice(2))"
+ git branch | deno -A https://deno.land/std/examples/xeval.ts -I 'line' "if (line.startsWith('*')) console.log(line.slice(2))"
Demonstrates breaking the input up by space delimiter instead of by lines:
- cat LICENSE | deno -A https://deno.land/std/examples/xeval.ts -- -d " " "if ($ === 'MIT') console.log('MIT licensed')",
+ cat LICENSE | deno -A https://deno.land/std/examples/xeval.ts -d " " "if ($ === 'MIT') console.log('MIT licensed')",
USAGE:
deno -A https://deno.land/std/examples/xeval.ts [OPTIONS] <code>
@@ -40,98 +39,12 @@ export interface XevalOptions {
const DEFAULT_DELIMITER = "\n";
-// Generate longest proper prefix which is also suffix array.
-function createLPS(pat: Uint8Array): Uint8Array {
- const lps = new Uint8Array(pat.length);
- lps[0] = 0;
- let prefixEnd = 0;
- let i = 1;
- while (i < lps.length) {
- if (pat[i] == pat[prefixEnd]) {
- prefixEnd++;
- lps[i] = prefixEnd;
- i++;
- } else if (prefixEnd === 0) {
- lps[i] = 0;
- i++;
- } else {
- prefixEnd = pat[prefixEnd - 1];
- }
- }
- return lps;
-}
-
-// Read from reader until EOF and emit string chunks separated
-// by the given delimiter.
-async function* chunks(
- reader: Reader,
- delim: string
-): AsyncIterableIterator<string> {
- const encoder = new TextEncoder();
- const decoder = new TextDecoder();
- // Avoid unicode problems
- const delimArr = encoder.encode(delim);
- const delimLen = delimArr.length;
- const delimLPS = createLPS(delimArr);
-
- let inputBuffer = new Buffer();
- const inspectArr = new Uint8Array(Math.max(1024, delimLen + 1));
-
- // Modified KMP
- let inspectIndex = 0;
- let matchIndex = 0;
- while (true) {
- const result = await reader.read(inspectArr);
- if (result === EOF) {
- // Yield last chunk.
- const lastChunk = inputBuffer.toString();
- yield lastChunk;
- return;
- }
- if ((result as number) < 0) {
- // Discard all remaining and silently fail.
- return;
- }
- const sliceRead = inspectArr.subarray(0, result as number);
- await writeAll(inputBuffer, sliceRead);
-
- let sliceToProcess = inputBuffer.bytes();
- while (inspectIndex < sliceToProcess.length) {
- if (sliceToProcess[inspectIndex] === delimArr[matchIndex]) {
- inspectIndex++;
- matchIndex++;
- if (matchIndex === delimLen) {
- // Full match
- const matchEnd = inspectIndex - delimLen;
- const readyBytes = sliceToProcess.subarray(0, matchEnd);
- // Copy
- const pendingBytes = sliceToProcess.slice(inspectIndex);
- const readyChunk = decoder.decode(readyBytes);
- yield readyChunk;
- // Reset match, different from KMP.
- sliceToProcess = pendingBytes;
- inspectIndex = 0;
- matchIndex = 0;
- }
- } else {
- if (matchIndex === 0) {
- inspectIndex++;
- } else {
- matchIndex = delimLPS[matchIndex - 1];
- }
- }
- }
- // Keep inspectIndex and matchIndex.
- inputBuffer = new Buffer(sliceToProcess);
- }
-}
-
export async function xeval(
reader: Reader,
xevalFunc: XevalFunc,
{ delimiter = DEFAULT_DELIMITER }: XevalOptions = {}
): Promise<void> {
- for await (const chunk of chunks(reader, delimiter)) {
+ for await (const chunk of readStringDelim(reader, delimiter)) {
// Ignore empty chunks.
if (chunk.length > 0) {
await xevalFunc(chunk);
@@ -140,7 +53,7 @@ export async function xeval(
}
async function main(): Promise<void> {
- const parsedArgs = parse(args.slice(1), {
+ const parsedArgs = parse(args, {
boolean: ["help"],
string: ["delim", "replvar"],
alias: {
@@ -155,6 +68,7 @@ async function main(): Promise<void> {
});
if (parsedArgs._.length != 1) {
console.error(HELP_MSG);
+ console.log(parsedArgs._);
exit(1);
}
if (parsedArgs.help) {
diff --git a/std/io/bufio.ts b/std/io/bufio.ts
index f721022f3..c0a52ac6a 100644
--- a/std/io/bufio.ts
+++ b/std/io/bufio.ts
@@ -508,3 +508,102 @@ export class BufWriter implements Writer {
return nn;
}
}
+
+/** Generate longest proper prefix which is also suffix array. */
+function createLPS(pat: Uint8Array): Uint8Array {
+ const lps = new Uint8Array(pat.length);
+ lps[0] = 0;
+ let prefixEnd = 0;
+ let i = 1;
+ while (i < lps.length) {
+ if (pat[i] == pat[prefixEnd]) {
+ prefixEnd++;
+ lps[i] = prefixEnd;
+ i++;
+ } else if (prefixEnd === 0) {
+ lps[i] = 0;
+ i++;
+ } else {
+ prefixEnd = pat[prefixEnd - 1];
+ }
+ }
+ return lps;
+}
+
+/** Read delimited bytes from a Reader. */
+export async function* readDelim(
+ reader: Reader,
+ delim: Uint8Array
+): AsyncIterableIterator<Uint8Array> {
+ // Avoid unicode problems
+ const delimLen = delim.length;
+ const delimLPS = createLPS(delim);
+
+ let inputBuffer = new Deno.Buffer();
+ const inspectArr = new Uint8Array(Math.max(1024, delimLen + 1));
+
+ // Modified KMP
+ let inspectIndex = 0;
+ let matchIndex = 0;
+ while (true) {
+ const result = await reader.read(inspectArr);
+ if (result === Deno.EOF) {
+ // Yield last chunk.
+ yield inputBuffer.bytes();
+ return;
+ }
+ if ((result as number) < 0) {
+ // Discard all remaining and silently fail.
+ return;
+ }
+ const sliceRead = inspectArr.subarray(0, result as number);
+ await Deno.writeAll(inputBuffer, sliceRead);
+
+ let sliceToProcess = inputBuffer.bytes();
+ while (inspectIndex < sliceToProcess.length) {
+ if (sliceToProcess[inspectIndex] === delim[matchIndex]) {
+ inspectIndex++;
+ matchIndex++;
+ if (matchIndex === delimLen) {
+ // Full match
+ const matchEnd = inspectIndex - delimLen;
+ const readyBytes = sliceToProcess.subarray(0, matchEnd);
+ // Copy
+ const pendingBytes = sliceToProcess.slice(inspectIndex);
+ yield readyBytes;
+ // Reset match, different from KMP.
+ sliceToProcess = pendingBytes;
+ inspectIndex = 0;
+ matchIndex = 0;
+ }
+ } else {
+ if (matchIndex === 0) {
+ inspectIndex++;
+ } else {
+ matchIndex = delimLPS[matchIndex - 1];
+ }
+ }
+ }
+ // Keep inspectIndex and matchIndex.
+ inputBuffer = new Deno.Buffer(sliceToProcess);
+ }
+}
+
+/** Read delimited strings from a Reader. */
+export async function* readStringDelim(
+ reader: Reader,
+ delim: string
+): AsyncIterableIterator<string> {
+ const encoder = new TextEncoder();
+ const decoder = new TextDecoder();
+ for await (const chunk of readDelim(reader, encoder.encode(delim))) {
+ yield decoder.decode(chunk);
+ }
+}
+
+/** Read strings line-by-line from a Reader. */
+export async function* readLines(
+ reader: Reader
+): AsyncIterableIterator<string> {
+ yield* readStringDelim(reader, "\n");
+}
diff --git a/std/io/bufio_test.ts b/std/io/bufio_test.ts
index 665c25361..4f4bd48b1 100644
--- a/std/io/bufio_test.ts
+++ b/std/io/bufio_test.ts
@@ -15,7 +15,9 @@ import {
BufReader,
BufWriter,
BufferFullError,
- UnexpectedEOFError
+ UnexpectedEOFError,
+ readStringDelim,
+ readLines
} from "./bufio.ts";
import * as iotest from "./iotest.ts";
import { charCode, copyBytes, stringsReader } from "./util.ts";
@@ -381,3 +383,28 @@ Deno.test(async function bufReaderReadFull(): Promise<void> {
}
}
});
+
+Deno.test(async function readStringDelimAndLines(): Promise<void> {
+ const enc = new TextEncoder();
+ const data = new Buffer(
+ enc.encode("Hello World\tHello World 2\tHello World 3")
+ );
+ const chunks_ = [];
+
+ for await (const c of readStringDelim(data, "\t")) {
+ chunks_.push(c);
+ }
+
+ assertEquals(chunks_.length, 3);
+ assertEquals(chunks_, ["Hello World", "Hello World 2", "Hello World 3"]);
+
+ const linesData = new Buffer(enc.encode("0\n1\n2\n3\n4\n5\n6\n7\n8\n9"));
+ const lines_ = [];
+
+ for await (const l of readLines(linesData)) {
+ lines_.push(l);
+ }
+
+ assertEquals(lines_.length, 10);
+ assertEquals(lines_, ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]);
+});
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-24 20:19:56 +0000