DeckCheck

DeckCheck is an offline command-line checker for flashcard decks, written in Salam. It catches editing mistakes before a TSV deck is imported into a study app.

The input format is one card per line: question<TAB>answer<TAB>topic. DeckCheck detects malformed rows and blank questions or answers, keeping the original physical line numbers in its diagnostics. Blank lines and # comments are ignored. A comment starts with # in the question segment after leading whitespace; a hash in the answer or topic does not hide a row. Questions that start with # are reserved for comments. A deck with no cards fails validation.

Complete cards with repeated questions are errors. Questions are trimmed and Unicode case-folded for comparison; the diagnostic points to the first occurrence. Answers and topics do not affect duplicate detection. Field trimming recognizes Unicode whitespace, including non-breaking spaces.

Topic counts include unique complete cards only. Labels are trimmed and grouped without case distinctions, keeping the first spelling and first-appearance order. An empty topic is allowed and appears as No topic. UTF-8 deck content is preserved.

Both LF and CRLF line endings and an optional UTF-8 BOM are supported. Empty fields and physical blank lines are preserved by the reader. Quoted fields, escaped tabs, headers, and multiline cards are outside this simple TSV format. Rows consisting of tab-separated empty fields are cards and fail validation; only whitespace-only lines without tabs are ignored. NUL-containing files are rejected as unreadable, since Salam's native strings cannot represent NUL bytes. Unicode normalization forms are not merged. The v0.4.7 Windows native runtime may mishandle non-ASCII command-line paths; use an ASCII path if a file cannot be opened.

Build

Use Salam v0.4.7 or a compatible release, with its standard library available:

New-Item -ItemType Directory -Force build | Out-Null
salam build src/main.salam --output=build/deckcheck.exe
./build/deckcheck.exe fixtures/clean.tsv

DeckCheck source is copyright 2026 Jaye, licensed under GPL-3.0-only. It imports the GPL-3.0 Salam standard library. See LICENSE.

Exit codes: 0 for a passing deck/help, 1 for validation errors, 2 for incorrect usage or an unreadable path. All fixtures contain synthetic content.

Functional checks

The PowerShell runner builds the real native program and checks its output and exit codes against 31 cases, including BOM/CRLF, physical line numbers, Unicode case folding, trailing empty fields, empty decks, and embedded NUL rejection. It writes only to ignored build/ files; it does not change input fixtures.

pwsh -File ./tests/functional.ps1 -Compiler salam

If Salam is not on your PATH, pass its executable path as -Compiler. This project was tested with the official Windows v0.4.7 release. Its native build uses the release's bundled toolchain. The regression runner requires PowerShell 7; it was tested with PowerShell 7.6.5. Windows PowerShell 5.1 does not reliably decode this UTF-8 script's Unicode literals.

Source layout

src/main.salam coordinates the CLI. cli supplies help, loader reads bytes and preserves physical lines, parser extracts fields, card defines a card, validator checks row completeness, duplicates checks prompts, normalizer folds Unicode case, topics groups coverage, summary defines totals, and report prints results. The sample decks exercise valid, broken, repeated, and multilingual cards. All eleven Salam modules are used by the executable.

DeckCheck reads the entire deck into memory. It is intended for local study decks, not arbitrarily large untrusted binary data. It performs no network calls and does not rewrite or export a deck. The Git history records actual successive development stages and subsequent functional verification.