Building for Production

When you’re satisfied with your program and ready to create a production build, the Grain CLI provides a few tools to help you create small, efficient WebAssembly binaries.

The release profile

Compiling with the release profile turns on a number of additional optimizations that make the resulting Wasm file significantly smaller and faster than the development builds, at the cost of a bit more compilation time. The release profile can be enabled via the --release flag:

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grain compile --release program.gr

Dropping runtime type information

Since Grain programs are fully typechecked at compile time, runtime type information is only necessary for the generic print and toString functions, typically used for debugging. If your programs do not rely on print or toString for enum variants or records, you can drop all runtime type information from the module to get them a bit smaller:

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grain compile --release --elide-type-info program.gr

Without runtime type information, print will continue to print strings, characters, booleans, numbers, tuples, and arrays normally. The affected values are only enum variants (including lists) and records, which will print as <enum value> and <record value> respectively. If this constraint is acceptable, you can take advantage of this flag and reduce your module sizes by a few kilobytes.