types

C WASM - Working With Types

This example package demonstrates compiling a C program, types.c which working with types pased to WASM from JS

Compiling C to WASM

emcc is required to compile the add.c code to a WASM binary:

npm run build

A types.wasm file will be produced in the build directory

Testing

Test the module outside of the context of the blockchain:

npm test

This will run NodeJS based tests in the test directory. For example in types.unit.spec.js test instantiation of the compiled WASM module, and assertions to verify its API and behavior:

describe('Integers', function () {
        it('Mult Ints', async function () {
            assert.strictEqual(wasm.instance.exports._mult(3, 99), 297); //Assert that the product of 3 and 99 is 297, checking strictly that the type return is equal to number
        });
    
    ...
    });

JS API

_getTen() - int

Return the number 10

_add(int x, int y) - int

Add two integers, return the result

_mult(int x, int y) - int

Multiply two integers, return the result

_getTenPointZeroOne() - double

Return the double representation of 10.01

IN PROGRESS:_addFloats(number x, number y) - number

Returns the float result of adding two floating point numbers together

_getTrue() - integer

Return the integer representation of true (1)

_getFalse() - integer

Return the integer representation of false (0)

_echo(boolean x) - integer

Return the integer representation of boolean x

_negate(boolean x) - integer

Return the boolean negation of integer representation of boolean x

_or(boolean x, boolean y) - integer

Return the integer representation of boolean x or'd with boolean y

_getString() - integer

Returns a pointer in memory to a string "It's Alive!!!"

IN PROGRESS: _echoString(string x) - integer

Returns a pointer in memory to string x