Global constants can be defined in wasm or in ModuleBuilder. In either
case, they end up being decoded and interpreted during instantiation.
This chooses signed encoding to avoid surprises. A more comprehensive
explanation was added to RATIONALE.md, but the motivation was a global
100 coming out negative.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adjusts towards the exiting code which used int32/64 instead of
uint32/64. The reason is that the spec indicates intepretation as signed
numbers, which affects the maximum value.
See https://www.w3.org/TR/wasm-core-1/#value-types%E2%91%A2
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This moves to a new end-user API under the root package `wazero`. This
simplifies call sites while hardening function calls to their known
return value. Most importantly, this moves most logic internal, as
noted in the RATIONALE.md.
Ex.
```go
// Read WebAssembly binary containing an exported "fac" function.
source, _ := os.ReadFile("./tests/engine/testdata/fac.wasm")
// Decode the binary as WebAssembly module.
mod, _ := wazero.DecodeModuleBinary(source)
// Initialize the execution environment called "store" with Interpreter-based engine.
store := wazero.NewStore()
// Instantiate the module, which returns its exported functions
functions, _ := store.Instantiate(mod)
// Get the factorial function
fac, _ := functions.GetFunctionI64Return("fac")
// Discover 7! is 5040
fmt.Println(fac(context.Background(), 7))
```
PS I changed the README to factorial because the wat version of
fibonacci is not consistent with the TinyGo one!
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Co-authored-by: Takaya Saeki <takaya@tetrate.io>
Co-authored-by: Takeshi Yoneda <takeshi@tetrate.io>
