compile.js

function compile(o, cx) {
    // initial evaluation context inherits from external cx or configuration object
    cx = new Context(cx);
    // track initial evaluation context in quotation scope
    const quots = [cx];
    // this is a reduction into a single result (a callable context)
    return o.reduce((cx, node) => {
        const type = node.type;
        if (isClose(type)) {
            // handle node close:
            // contains reference to the node that closes...
            if (isQuotNode(node.node)) {
                // handle quotation close:
                // if we're in a quotation context, close it
                const dest = quots.pop();
                // get the current target from the scope array (uses https://github.com/keithamus/proposal-array-last)
                // target is either a quotation or the initial evaluation context
                const target = quots.last();
                target.append(dest);
            } else {
                // find the current target
                const target = quots.last();
                if (isVarNode(node.node)) {
                    // handle var or param:
                    const count = node.node.count();
                    if (count > 1 && node.node.depth == 1) {
                        // handle private top-level declaration: simply add as export
                        target.addExport(count);
                    } else {
                        target.addVar(count);
                    }
                } else if (isModuleNode(node.node)) {
                    // handle module insertion:
                    target.addModule(node.node);
                } else if (isImportNode(node.node)) {
                    // handle import:
                    target.addImport(node.node);
                } else if (isExportNode(node.node)) {
                    // handle export:
                    // expect type to be compiled to a single Call
                    target.addExport(node.node.count());
                } else if (isPartialNode(node.node)) {
                    // handle partial:
                    // append partial sentinel for papply-any to stack
                    target.append($_);
                } else {
                    // retrieve call from last open
                    target.addCall(node.node.name, node.node.count());
                }
            }
        } else if (isDirect(type)) {
            // handle direct call of inline quotation or function reference:
            // e.g.
            // add#2(3,4)
            // OR
            // {add($(1),$(2))}(3,4)
            // should call last on stack
            // NOTE these may be chained!
            target.addDirect(node.node);
        } else if (isLeaf(type)) {
            // handle leaf (Datum):
            // find the current target
            const target = quots.last();
            // NOTE comments are emitted, but should be ignored
            target.addDatum(node.type, node.value);
        } else if (isBranch(type)) {
            if (isQuotNode(node)) {
                // handle quotation:
                // open new quotation scope (closure)
                quots.push(new Quot(cx));
            }
        }
        return cx;
    }, cx); //.map(cx => cx.apply());
}