CLI Output

対象実装: このドキュメントは NEPLg2.0（現行 nepl-core）の CLI 仕様を記述する。
NEPLg2.1 では ownership check と Resource IR analysis などの検査が追加される想定であり、ここで説明する現在の CLI 挙動とは一致しない部分がある（doc/2.1impl/compiler_structure.md 参照）。

This document describes NEPL CLI output options and file naming.

Output base

--output is treated as a base path. Extensions are added depending on --emit.

Examples:

  • --output out/a writes out/a.wasm, out/a.wat, out/a.min.wat (depending on --emit).
  • --output out/a.wasm is treated as base out/a.
  • --output out/a.wat is treated as base out/a.
  • --output out/a.min.wat is treated as base out/a.

Targets

--target selects the compilation target (default: wasm):

TargetDescription
wasmPure WebAssembly (no WASI imports)
wasiWebAssembly with WASI syscalls
llvmNative binary via LLVM

The current compiler keeps typecheck / effect-check behavior consistent across targets. Only the physical layout and allocator differ (absorbed by #if[target="..."] in stdlib). NEPLg2.1 is planned to add ownership check and Resource IR analysis uniformly across all targets.

Emit formats

--emit accepts one or more values (comma-separated or repeated). Applies to Wasm targets:

  • wasm outputs the binary .wasm.
  • wat outputs a readable WAT.
  • wat-min outputs a minified WAT.
  • all expands to wasm, wat, wat-min.

Examples:

nepl-cli --input examples/counter.nepl --output target/counter --emit wasm
nepl-cli --input examples/counter.nepl --output target/counter --emit wat
nepl-cli --input examples/counter.nepl --output target/counter --emit wasm,wat,wat-min

Profile

--profile controls #if[profile=...] gates in source:

  • --profile debug enables #if[profile=debug]
  • --profile release enables #if[profile=release]

If omitted, the compiler uses the build profile it was compiled with.

Run and program arguments

When --run is used, arguments after -- are passed to the WASI program.
The program name is always provided as argv[0] (input path or <stdin>).

Example:

nepl-cli --input examples/counter.nepl --run -- --flag value

WAT generation

  • Pretty WAT uses the default formatting from wasmprinter.
  • Minified WAT compresses whitespace after printing.
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