Opening this issue to follow up the discussion of #94 (comment).

@pyu10055 mentioned:

With this API, the computation is tied with the compilation. should the compile method have the inputs/outputs pair and execution can only execution the graph compiled with the input/output pair? Otherwise, the compilation might not support the execution of the sub-graph scenario?

Actually, the existing builder.createModel allows to specify the outputs. With that, developers could create different sub-graphs (models) from a topology within a builder and compile/compute them individually. For example:

const builder = nn.createModelBuilder();
const a = builder.input('a', descA);
const b = builder.constant(descB, bufferB);
const c = builder.constant(descC, bufferC);
const d = builder.mul(a, b);
const e = builder.add(d, c);
const model1 = builder.createModel({d}); // d = a * b
const model2 = builder.createModel({e}); // e = a* b + c

@pyu10055 , please let us know any gaps of the existing API and share more details of your proposal. Thanks!