Language overview

Goalchemy accepts ordinary Go syntax under a restricted semantic profile. The source baseline is Go 1.25 on Linux amd64 with cgo disabled; the reference compiler is Go 1.27.1. A newer source language requirement is rejected.

Two gates

Gate	Adds
sequential	Packages, initialization, functions, methods, closures, integers, floats, strings, structs, arrays, slices, maps, supported pointers, interfaces, control flow, errors, and deferred calls.
cooperative	Source tasks, channels, select, synchronization, cancellation, and resumable execution.

Select the gate with -gate or project configuration. Check the feature matrix for tested coverage. The specification describes semantic intent; the manifest and fixtures establish implemented support.

Semantics belong to the source

Emitters preserve a typed intermediate representation rather than relying on host-language defaults. Examples include:

Source behavior	Consequence across targets
Fixed-width integer operations	Source overflow and conversion rules survive JavaScript numbers and C arithmetic differences.
Byte-based strings	Length, indexing, slicing, and invalid UTF-8 preserve Go observations.
Struct and array copies	Assignment copies values even when a host would share objects.
Slice aliasing	Aliases share backing storage while retaining separate headers.
Dynamic interfaces	Type identity, method sets, and typed nil values are preserved.
Panic and defer	Source unwinding is separate from a host implementation failure.

Read the language specification for the exact rules and floating-point semantics for IEEE behavior.

Unsupported constructs fail early

Generics, complex numbers, source reflection, unsafe, cgo, arbitrary goto, and slice/array element pointers are outside the accepted profile. Imported code is checked too. See limitations before designing a public API.

Run goalchemy check -json . for structured diagnostics. Diagnostic codes retain their category and meaning across text and JSON forms; see diagnostics.