move files to backend subdir, push data in submodule

1 files changed, 72 insertions, 0 deletions

diff --git a/backend/utils.js b/backend/utils.js
new file mode 100644
index 0000000..6cff356
--- /dev/null
+++ b/backend/utils.js
@@ -0,0 +1,72 @@
+#!/usr/bin/node
+
+const R = require('ramda');
+
+const lengthEq = (n) => R.compose(R.equals(n), R.length);
+const list = R.unapply(R.identity);
+const unlist = R.apply(R.identity);
+const mergeAllArgs = R.compose(R.mergeAll, list);
+const objOfPath = R.curry((objOf, path) => R.compose(R.objOf(objOf), R.path(path)));
+const andAll = R.all(R.equals(R.T()));
+const andAllArgs = R.compose(andAll, list);
+
+const projectProps = R.curry(
+  (proj, d) => R.compose(R.prop(0), R.project(proj), R.of)(d)
+);
+
+const joinRight = R.curry((mapper1, mapper2, t1, t2) => {
+  let indexed = R.indexBy(mapper1, t1);
+  return t2.map((t2row) => R.merge(t2row, indexed[mapper2(t2row)]));
+});
+
+const commonKeys = R.useWith(R.intersection, [
+  R.keys,
+  R.keys,
+]);
+
+const naturalJoinRight = R.curry((t1, t2) => joinRight(
+  R.props(commonKeys(t1[0], t2[0])),
+  R.props(commonKeys(t1[0], t2[0])),
+  t2,
+  t1,
+));
+
+const eqPropses = R.curry((props) => // TODO should create function with arity 3 but doesn't because it's nested
+  R.converge(andAllArgs, R.map(R.eqProps, props))
+);
+
+const mergeAllWith = (merger) => R.until(lengthEq(1), R.pipe( // TODO same issue
+  R.splitEvery(2),
+  R.map(
+    R.ifElse(lengthEq(2), // TODO refactor
+             R.apply(R.mergeWith(merger)),
+             R.apply(R.identity))
+  )
+));
+
+const divPropsByProp = R.curry((prop, props, data) => { // TODO refactor
+  return R.fromPairs(
+    R.map((aProp) =>
+          R.contains(aProp, props) ?
+            [aProp, R.prop(aProp, data) / R.prop(prop, data)]
+          : [aProp, R.prop(aProp, data)],
+          R.keys(data),
+    )
+  );
+});
+
+module.exports = {
+  list,
+  unlist,
+  mergeAllArgs,
+  objOfPath,
+  andAll,
+  andAllArgs,
+  joinRight,
+  naturalJoinRight,
+  eqPropses,
+  lengthEq,
+  mergeAllWith,
+  projectProps,
+  divPropsByProp,
+};