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Ada (Wasm)

Ada is a statically typed, high-level programming language designed for safety, reliability and maintainability.

In LiveCodes, Ada is compiled and run entirely in the browser by HAC, an Ada compiler written in Ada and compiled to WebAssembly. No backend is involved.

Note

HAC implements a subset of Ada 2022 (roughly the "Pascal subset" plus packages): no access types (pointers), no generics, and only constrained types. I/O is provided by the built-in HAT package.

Usage​

Demo:

show code
import { createPlayground } from 'livecodes';

const options = {
  "config": {
    "activeEditor": "script",
    "script": {
      "language": "ada-wasm",
      "content": "with HAT; use HAT;\n\nprocedure Ada_Demo is\n  function Fibonacci (N : Natural) return Natural is\n  begin\n    if N < 2 then\n      return N;\n    else\n      return Fibonacci (N - 1) + Fibonacci (N - 2);\n    end if;\n  end Fibonacci;\nbegin\n  Put_Line (\"Hello from Ada, running in your browser!\");\n  for I in 0 .. 10 loop\n    Put (\"Fib (\");\n    Put (I, 1);\n    Put (\") = \");\n    Put_Line (Fibonacci (I), 1);\n  end loop;\nend Ada_Demo;"
    },
    "mode": "simple",
    "editor": "auto",
    "tools": {
      "status": "full"
    }
  }
};
createPlayground('#container', options);

Standard I/O​

Ada code runs in the context of the result page. Standard output (e.g. HAT.Put and HAT.Put_Line) is captured and displayed in the console. Standard input is passed by setting the livecodes.ada.input property in JavaScript and is read in Ada using HAT.Get/HAT.Get_Line.

Communication with JavaScript​

The Ada code runs in the context of the result page. A few helper properties and methods are available in the browser global livecodes.ada object:

  • livecodes.ada.input: The standard input passed to the Ada program. It can be set before the initial run, or passed to run for subsequent runs.
  • livecodes.ada.loaded: A promise that resolves when the Ada compiler is fully loaded (and rejects if it fails to load). Other helpers should be used after this promise resolves.
  • livecodes.ada.output: The standard output of the last run.
  • livecodes.ada.error: The compiler diagnostics or runtime error of the last run, if any.
  • livecodes.ada.exitCode: The exit code of the last run.
  • livecodes.ada.run(input): Runs the code in the editor, optionally passing standard input, and returns a promise that resolves to { output, error, exitCode }.
await livecodes.ada.loaded;
const { output, error, exitCode } = await livecodes.ada.run(livecodes.ada.input);
console.log(output);

Language Info​

Name​

ada-wasm

Aliases / Extensions​

ada, adb, ads, hac, wasm.ada

Editor​

script

Compiler​

HAC (HAC Ada Compiler), an Ada compiler and p-code virtual machine written in Ada, compiled to WebAssembly. It is packaged for the browser by @live-codes/ada-wasm.

Version​

HAC 0.45

Code Formatting​

Not supported.

Limitations​

HAC implements a subset of Ada, so not all Ada programs compile:

  • No access types (pointers), no generics, and only constrained types.
  • String support is limited; use HAT.VString for variable-length strings.
  • Tasking is partially implemented.
  • Programs are single-file. Use the HAT package for input/output.

Example Usage​

This example passes standard input and runs the code again on each click, using the browser global livecodes.ada (also check the code in the HTML editor):

show code
import { createPlayground } from 'livecodes';

const options = {
  "template": "ada-wasm"
};
createPlayground('#container', options);

Live Reload​

By default, new code changes are sent to the result page for re-evaluation without a full page reload, avoiding the need to reinitialize the Ada WebAssembly compiler. This behavior can be disabled by adding the code comment -- __livecodes_reload__ to the Ada code, which forces a full page reload.

This comment can be added in the hiddenContent property of the editor for embedded playgrounds.

Starter Template​

https://livecodes.io/?template=ada-wasm

Sponsors