Daslang Documentation

The detect-dupe utility is a cross-file similar-function detector for .das files. It walks a directory tree, normalizes user functions into an alpha-renamed token stream (collapsing identifiers, types, and literals), and identifies two types of duplicates:

1. Exact-clone clusters: Functions that hash to the same canonical text (pure structural duplicates).
2. Fuzzy near-duplicates: Pairs scored using a MinHash signature and a Jaccard similarity estimate, subject to a length ratio threshold to prevent false positives from periodic boilerplate.

It is useful for finding test-suite boilerplate, near-clones that have drifted, or copy-pasted helpers.

The perf_lint module (located in daslib/perf_lint.das) is a compile-time tool that detects common performance anti-patterns in daslang code. It operates as a [lint_macro] AST pass that walks the compiled program. When a slow pattern is detected, it reports a warning using error code 31208 (CompilationError::runtime_macro_performance).

Key components:

• Module: daslib/perf_lint.das (module perf_lint shared private)
• Entry point: [lint_macro] class PerfLintMacro : AstPassMacro
• Visitor: class PerfLintVisitor : AstVisitor (tracks loop depth and variable scopes)
• Unified Linting: utils/lint/main.das provides a single interface to run paranoid, performance, and style linting passes.

The {fmt} library is a modern C++ formatting library designed to address the limitations of existing formatting methods. It aims to provide a solution that is faster than Boost Format, safer and more concise than iostreams (avoiding "chevron hell"), and more feature-complete than FastFormat (supporting leading zeros, octal/hexadecimal encoding, and runtime width/alignment specification).

Key comparisons:

• printf: Fast and available, but lacks support for user-defined types and has safety concerns.
• iostreams: Supports user-defined types and is safe, but suffers from verbose syntax and lacks positional arguments.
• Boost Format: Powerful and supports positional arguments, but suffers from poor performance, high build times, and code bloat.
• FastFormat: Fast and safe, but lacks leading zeros, octal/hexadecimal encoding, and runtime width/alignment specification.

Daslang is a high-performance, strongly and statically typed scripting language designed for real-time applications like games. It is intended to be used as an embeddable "host data processor," where the script transforms host (C++) data or implements scripted behaviors.

Key characteristics include:

• Performance: High-speed interpretation and extremely fast two-way interop with C++.
• Memory Model: Designed to be pure functional in nature; persistent state is typically managed by the host application, leading to a simple and fast memory model within Daslang.
• Compilation: Supports Ahead-of-Time (AoT) compilation to C++, providing performance similar to C++11.

vecmath is a header-only Hardware Abstraction Layer (HAL) for SIMD intrinsics. It provides a unified interface for vector and matrix mathematics across different SIMD architectures.

Supported Architectures:

• SSE (x86)
• NEON (ARM)

Supported Platforms:

• PC, Linux, MacOS, iOS, tvOS, Shield, NSwitch, PlayStation 4, Xbox One.

Compiler Support:

• GCC (various versions)
• Clang 3.9+
• Visual Studio 2015, 2017, 2019, 2022

Requirements:

• Requires C++11 or later (uses alignas for memory alignment).
• Minimum instruction set requirement: SSE2.

benchctl is a command-line tool for storing, querying, and comparing daslang benchmark results across different commits or tags. It uses a local SQLite database to persist benchmark data and provides statistical comparisons between two sets of results (e.g., comparing an old algorithm against a new one).

Key features include:

• Inserting benchmark JSON output from dastest into a persistent database.
• Querying results using commit hashes or custom tags.
• Computing geometric mean deltas and statistical significance (using Welch's t-test) between result sets.
• Integration with dastest via the --bench-format json flag.