RosettaCodeData/Task/Hello-world-Text/WebAssembly/hello-world-text.wasm

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(module $helloworld
;;Import fd_write from WASI, declaring that it takes 4 i32 inputs and returns 1 i32 value
(import "wasi_unstable" "fd_write"
(func $fd_write (param i32 i32 i32 i32) (result i32))
)
;;Declare initial memory size of 32 bytes
(memory 32)
;;Export memory so external functions can see it
(export "memory" (memory 0))
;;Declare test data starting at address 8
(data (i32.const 8) "Hello world!\n")
;;The entry point for WASI is called _start
(func $main (export "_start")
;;Write the start address of the string to address 0
(i32.store (i32.const 0) (i32.const 8))
;;Write the length of the string to address 4
(i32.store (i32.const 4) (i32.const 13))
;;Call fd_write to print to console
(call $fd_write
(i32.const 1) ;;Value of 1 corresponds to stdout
(i32.const 0) ;;The location in memory of the string pointer
(i32.const 1) ;;Number of strings to output
(i32.const 24) ;;Address to write number of bytes written
)
drop ;;Ignore return code
)
)