From 41f48585ee16bdbd9744956bb790062fb53a69c7 Mon Sep 17 00:00:00 2001
From: Nicolas Lepage <19571875+nlepage@users.noreply.github.com>
Date: Fri, 26 Jul 2019 16:24:38 +0200
Subject: [PATCH] :sparkles: Slices get

---
 packages/immutadot/src/core/apply.js      | 18 +++---
 packages/immutadot/src/core/apply.spec.js |  4 --
 packages/immutadot/src/core/get.js        | 12 +---
 packages/immutadot/src/core/get.spec.js   |  2 +-
 packages/immutadot/src/core/set.js        |  1 +
 packages/immutadot/src/core/unset.js      |  3 +-
 packages/immutadot/src/nav/nav.js         | 25 +--------
 packages/immutadot/src/nav/nav.spec.js    | 32 +++++------
 packages/immutadot/src/nav2/indexNav.js   |  2 +-
 packages/immutadot/src/nav2/nav.js        | 10 +++-
 packages/immutadot/src/nav2/nav.spec.js   | 45 ---------------
 packages/immutadot/src/nav2/sliceNav.js   | 68 +++++++++++++++++++++++
 12 files changed, 109 insertions(+), 113 deletions(-)
 delete mode 100644 packages/immutadot/src/nav2/nav.spec.js
 create mode 100644 packages/immutadot/src/nav2/sliceNav.js

diff --git a/packages/immutadot/src/core/apply.js b/packages/immutadot/src/core/apply.js
index 56425e77..0af0282b 100644
--- a/packages/immutadot/src/core/apply.js
+++ b/packages/immutadot/src/core/apply.js
@@ -14,42 +14,42 @@ function apply(fn, { arity = fn.length, fixedArity = false, curried = true, lazy
     switch (arity) {
     case 0:
     case 1:
-      appliedFn = (obj, path) => nav(toPath(path))(obj).update(fn)
+      appliedFn = (obj, path) => nav(toPath(path)).update(fn)(obj)
       break
     case 2:
-      appliedFn = (obj, path, arg) => nav(toPath(path))(obj).update(
+      appliedFn = (obj, path, arg) => nav(toPath(path)).update(
         value => fn(value, resolveArg(arg, obj)),
-      )
+      )(obj)
       break
     case 3:
-      appliedFn = (obj, path, arg1, arg2) => nav(toPath(path))(obj).update(
+      appliedFn = (obj, path, arg1, arg2) => nav(toPath(path)).update(
         value => fn(
           value,
           resolveArg(arg1, obj),
           resolveArg(arg2, obj),
         ),
-      )
+      )(obj)
       break
     case 4:
-      appliedFn = (obj, path, arg1, arg2, arg3) => nav(toPath(path))(obj).update(
+      appliedFn = (obj, path, arg1, arg2, arg3) => nav(toPath(path)).update(
         value => fn(
           value,
           resolveArg(arg1, obj),
           resolveArg(arg2, obj),
           resolveArg(arg3, obj),
         ),
-      )
+      )(obj)
       break
     }
   }
 
   if (!appliedFn) {
-    appliedFn = (obj, path, ...args) => nav(toPath(path))(obj).update(
+    appliedFn = (obj, path, ...args) => nav(toPath(path)).update(
       value => fn(
         value,
         ...args.map(arg => resolveArg(arg, obj)),
       ),
-    )
+    )(obj)
   }
 
   if (curried) {
diff --git a/packages/immutadot/src/core/apply.spec.js b/packages/immutadot/src/core/apply.spec.js
index f627a146..4686f8f9 100644
--- a/packages/immutadot/src/core/apply.spec.js
+++ b/packages/immutadot/src/core/apply.spec.js
@@ -238,10 +238,6 @@ describe('path.apply', () => {
     })
   })
 
-  it('should throw an explicit error when en empty path is given as parameter', () => {
-    expect(() => inc({}, '')).toThrowError('path should not be empty')
-  })
-
   it('should support curried first arg', () => {
     immutaTest({
       nested: { prop: 5 },
diff --git a/packages/immutadot/src/core/get.js b/packages/immutadot/src/core/get.js
index 080a2c24..71523442 100644
--- a/packages/immutadot/src/core/get.js
+++ b/packages/immutadot/src/core/get.js
@@ -13,23 +13,17 @@ const isGetter = Symbol('isGetter')
 * @since 1.0.0
 */
 function get(...args) {
-  if (args.length >= 2)
-    return _get(...args)
+  if (args.length >= 2) return nav(toPath(args[1])).get()(args[0])
 
-  const getter = obj => _get(obj, ...args)
+  const getter = nav(toPath(args[0])).get()
   getter[isGetter] = true
 
   return getter
 }
 
-function _get(obj, path) {
-  return nav(toPath(path))(obj).get()
-}
-
 function resolveGetter(value, obj) {
   if (value && value[isGetter]) return value(obj)
   return value
 }
 
-// FIXME stop exporting isGetter
-export { get, isGetter, resolveGetter }
+export { get, resolveGetter }
diff --git a/packages/immutadot/src/core/get.spec.js b/packages/immutadot/src/core/get.spec.js
index c07704f2..3ae2b830 100644
--- a/packages/immutadot/src/core/get.spec.js
+++ b/packages/immutadot/src/core/get.spec.js
@@ -14,7 +14,7 @@ describe('core.get', () => {
     expect(get(obj, 'nested2.arr[0].val')).toBe('arrVal1')
   })
 
-  it('should get multiple props', () => {
+  it('should get slices of nested props', () => {
     expect(get(obj, 'nested2.arr[:].val')).toEqual(['arrVal1', 'arrVal2'])
     expect(get(obj, 'nested3[:][:].val')).toEqual([[1, 2], [3, 4]])
   })
diff --git a/packages/immutadot/src/core/set.js b/packages/immutadot/src/core/set.js
index 1e0ad715..fe7932dd 100644
--- a/packages/immutadot/src/core/set.js
+++ b/packages/immutadot/src/core/set.js
@@ -10,6 +10,7 @@ import { apply } from './apply'
  * @example set({ nested: { prop: 'old' } }, 'nested.prop', 'new') // => { nested: { prop: 'new' } }
  * @since 1.0.0
  */
+// FIXME do not use apply here ?
 const set = apply((_, value) => value, { fixedArity: true })
 
 export { set }
diff --git a/packages/immutadot/src/core/unset.js b/packages/immutadot/src/core/unset.js
index e89bc1e0..7d7ee6e1 100644
--- a/packages/immutadot/src/core/unset.js
+++ b/packages/immutadot/src/core/unset.js
@@ -12,6 +12,7 @@ import { toPath } from 'immutadot-parser'
  * @example unset({ nested: { prop: 'value' } }, 'nested.prop') // => { nested: {} }
  * @since 1.0.0
  */
-const unset = curry((obj, path) => nav(toPath(path))(obj).unset(), { fixedArity: true })
+// FIXME do not use curry here ?
+const unset = curry((obj, path) => nav(toPath(path)).unset()(obj), { fixedArity: true })
 
 export { unset }
diff --git a/packages/immutadot/src/nav/nav.js b/packages/immutadot/src/nav/nav.js
index 7ef96bfe..8beefee5 100644
--- a/packages/immutadot/src/nav/nav.js
+++ b/packages/immutadot/src/nav/nav.js
@@ -1,24 +1 @@
-import { NavType } from 'immutadot-parser'
-import { finalNav } from './finalNav'
-import { indexNav } from './indexNav'
-import { propNav } from './propNav'
-import { propsNav } from './propsNav'
-import { sliceNav } from './sliceNav'
-
-export function nav(path) {
-  if (path.length === 0) throw new TypeError('path should not be empty')
-
-  return path.reduceRight((next, [type, value]) => toNav(type)(value, next), finalNav)
-}
-
-function toNav(type) {
-  switch (type) {
-  case NavType.allProps:
-  case NavType.list:
-    return propsNav
-  case NavType.index: return indexNav
-  case NavType.prop: return propNav
-  case NavType.slice: return sliceNav
-  default: throw TypeError(type)
-  }
-}
+export { nav } from '../nav2/nav'
diff --git a/packages/immutadot/src/nav/nav.spec.js b/packages/immutadot/src/nav/nav.spec.js
index 3a4ade99..a706827a 100644
--- a/packages/immutadot/src/nav/nav.spec.js
+++ b/packages/immutadot/src/nav/nav.spec.js
@@ -13,7 +13,7 @@ describe('nav.nav', () => {
   }
 
   function uncurriedInc(obj, path, ...args) {
-    return nav(toPath(path))(obj).update(v => incV(v, ...args))
+    return nav(toPath(path)).update(v => incV(v, ...args))(obj)
   }
 
   function curriedInc(path, ...args) {
@@ -224,7 +224,7 @@ describe('nav.nav', () => {
   })
 
   it('should throw an explicit error when en empty path is given as parameter', () => {
-    expect(() => inc({}, '')).toThrowError('path should not be empty')
+    expect(() => inc({}, '')).toThrowError('Path should not be empty')
   })
 
   it('should support curried first arg', () => {
@@ -262,14 +262,14 @@ describe('nav.nav', () => {
   })
 
   it('should get a nested prop', () => {
-    expect(nav(toPath('nested.prop'))({ nested: { prop: 'foo' } }).get()).toBe('foo')
+    expect(nav(toPath('nested.prop')).get()({ nested: { prop: 'foo' } })).toBe('foo')
   })
 
   it('should get a list of props', () => {
-    expect(nav(toPath('nested.{prop1,prop2}'))({ nested: { prop1: 'foo',
-      prop2: 'bar' } }).get()).toEqual(['foo', 'bar'])
-    expect(nav(toPath('nested.{*}'))({ nested: { prop1: 'foo',
-      prop2: 'bar' } }).get()).toEqual(['foo', 'bar'])
+    expect(nav(toPath('nested.{prop1,prop2}')).get()({ nested: { prop1: 'foo',
+      prop2: 'bar' } })).toEqual(['foo', 'bar'])
+    expect(nav(toPath('nested.{*}')).get()({ nested: { prop1: 'foo',
+      prop2: 'bar' } })).toEqual(['foo', 'bar'])
   })
 
   it('should set a nested prop', () => {
@@ -277,7 +277,7 @@ describe('nav.nav', () => {
       { nested: { prop: 'foo' } },
       ['nested.prop'],
       (input, [path]) => {
-        const output = nav(toPath(path))(input).update(() => 'bar')
+        const output = nav(toPath(path)).update(() => 'bar')(input)
         expect(output).toEqual({ nested: { prop: 'bar' } })
         return output
       },
@@ -289,7 +289,7 @@ describe('nav.nav', () => {
       { nested: { prop: 'foo' } },
       ['nested.prop'],
       (input, [path]) => {
-        const output = nav(toPath(path))(input).update(value => value.toUpperCase())
+        const output = nav(toPath(path)).update(value => value.toUpperCase())(input)
         expect(output).toEqual({ nested: { prop: 'FOO' } })
         return output
       },
@@ -301,7 +301,7 @@ describe('nav.nav', () => {
       {},
       ['nested.prop.0', 'nested.prop.1'],
       input => {
-        const output = nav(toPath('nested.prop[1]'))(input).update(() => 'foo')
+        const output = nav(toPath('nested.prop[1]')).update(() => 'foo')(input)
         expect(output).toEqual({ nested: { prop: [undefined, 'foo'] } })
         return output
       },
@@ -309,26 +309,26 @@ describe('nav.nav', () => {
   })
 
   it('should get a slice', () => {
-    expect(nav(toPath('nested.prop[:].val'))({
+    expect(nav(toPath('nested.prop[:].val')).get()({
       nested: {
         prop: [
           { val: 'foo' },
           { val: 'bar' },
         ],
       },
-    }).get()).toEqual(['foo', 'bar'])
-    expect(nav(toPath('nested.prop[::-1].val'))({
+    })).toEqual(['foo', 'bar'])
+    expect(nav(toPath('nested.prop[::-1].val')).get()({
       nested: {
         prop: [
           { val: 'foo' },
           { val: 'bar' },
         ],
       },
-    }).get()).toEqual(['bar', 'foo'])
+    })).toEqual(['bar', 'foo'])
   })
 
   it('should get a negative array index', () => {
-    expect(nav(toPath('nested.prop[-3]'))({ nested: { prop: [0, 1, 2, 3, 4] } }).get()).toBe(2)
+    expect(nav(toPath('nested.prop[-3]')).get()({ nested: { prop: [0, 1, 2, 3, 4] } })).toBe(2)
   })
 
   it('should update a slice', () => immutaTest(
@@ -343,7 +343,7 @@ describe('nav.nav', () => {
     },
     ['nested.prop.1.val', 'nested.prop.2.val'],
     input => {
-      const output = nav(toPath('nested.prop[-2:].val'))(input).update(value => value.toUpperCase())
+      const output = nav(toPath('nested.prop[-2:].val')).update(value => value.toUpperCase())(input)
       expect(output).toEqual({
         nested: {
           prop: [
diff --git a/packages/immutadot/src/nav2/indexNav.js b/packages/immutadot/src/nav2/indexNav.js
index ded1c574..5066340a 100644
--- a/packages/immutadot/src/nav2/indexNav.js
+++ b/packages/immutadot/src/nav2/indexNav.js
@@ -44,7 +44,7 @@ const unset = (pIndex, next) => () => {
   })
 }
 
-export const propNav = makeNav({
+export const indexNav = makeNav({
   update,
   get,
   unset,
diff --git a/packages/immutadot/src/nav2/nav.js b/packages/immutadot/src/nav2/nav.js
index 34dc86bd..c363bce4 100644
--- a/packages/immutadot/src/nav2/nav.js
+++ b/packages/immutadot/src/nav2/nav.js
@@ -1,12 +1,16 @@
+import { NavType } from 'immutadot-parser'
 import { finalNav } from './finalNav'
 import { indexNav } from './indexNav'
 import { propNav } from './propNav'
 import { propsNav } from './propsNav'
+import { sliceNav } from './sliceNav'
 
 const navs = {
-  prop: propNav,
-  props: propsNav,
-  index: indexNav,
+  [NavType.prop]: propNav,
+  [NavType.list]: propsNav,
+  [NavType.allProps]: propsNav,
+  [NavType.index]: indexNav,
+  [NavType.slice]: sliceNav,
 }
 
 const toNav = ([type, params]) => {
diff --git a/packages/immutadot/src/nav2/nav.spec.js b/packages/immutadot/src/nav2/nav.spec.js
deleted file mode 100644
index dc04dfc1..00000000
--- a/packages/immutadot/src/nav2/nav.spec.js
+++ /dev/null
@@ -1,45 +0,0 @@
-/* eslint-env jest */
-import { immutaTest } from 'test.utils'
-import { nav } from './nav'
-
-describe('nav.nav', () => {
-  it('should update a nested prop', () => immutaTest(
-    {
-      nested: { prop: 'foo' },
-      other: { prop: 'baz' },
-    },
-    ['nested.prop'],
-    input => {
-      const output = nav([['prop', 'nested'], ['prop', 'prop']]).update(() => 'bar')(input)
-      expect(output).toEqual({
-        nested: { prop: 'bar' },
-        other: { prop: 'baz' },
-      })
-      return output
-    },
-  ))
-
-  it('should get a nested prop', () => {
-    const input = {
-      nested: { prop: 'foo' },
-      other: { prop: 'baz' },
-    }
-    expect(nav([['prop', 'nested'], ['prop', 'prop']]).get()(input)).toEqual('foo')
-  })
-
-  it('should unset a nested prop', () => immutaTest(
-    {
-      nested: { prop: 'foo' },
-      other: { prop: 'bar' },
-    },
-    ['nested.prop'],
-    input => {
-      const output = nav([['prop', 'nested'], ['prop', 'prop']]).unset()(input)
-      expect(output).toEqual({
-        nested: {},
-        other: { prop: 'bar' },
-      })
-      return output
-    },
-  ))
-})
diff --git a/packages/immutadot/src/nav2/sliceNav.js b/packages/immutadot/src/nav2/sliceNav.js
new file mode 100644
index 00000000..841e9dc9
--- /dev/null
+++ b/packages/immutadot/src/nav2/sliceNav.js
@@ -0,0 +1,68 @@
+import { length as getLength, isNil } from 'util/lang'
+import { makeNav } from './makeNav'
+import { onCopy } from './arrayNav'
+
+const resolveIndex = (index, length) => index >= 0 ? index : Math.max(length + index, 0)
+
+const resolveStart = (pStart, length, step) => {
+  if (length === 0) return 0
+  if (pStart === undefined) return step > 0 ? 0 : length - 1
+  return resolveIndex(pStart, length)
+}
+
+const resolveEnd = (pEnd, length, step) => {
+  if (length === 0) return 0
+  if (pEnd === undefined) return step > 0 ? length : -1
+  return resolveIndex(pEnd, length)
+}
+
+const update = ([pStart, pEnd, pStep], next) => updater => {
+  const nextUpdater = next(updater)
+  const step = pStep === undefined ? 1 : pStep
+  return onCopy((newValue, value) => {
+    const length = getLength(value)
+    const start = resolveStart(pStart, length, step)
+    const end = resolveEnd(pEnd, length, step)
+    if (step > 0) {
+      if (end <= start) return // TODO avoid useless copy
+      if (isNil(value))
+        for (let i = start; i < end; i += step) newValue[i] = nextUpdater(undefined)
+      else
+        for (let i = start; i < end; i += step) newValue[i] = nextUpdater(value[i])
+    }
+    if (end >= start) return // TODO avoid useless copy
+    if (isNil(value))
+      for (let i = start; i > end; i += step) newValue[i] = nextUpdater(undefined)
+    else
+      for (let i = start; i > end; i += step) newValue[i] = nextUpdater(value[i])
+  }, true)
+}
+
+const get = ([pStart, pEnd, pStep], next) => () => {
+  const nextGetter = next()
+  const step = pStep === undefined ? 1 : pStep
+  return value => {
+    const length = getLength(value)
+    const start = resolveStart(pStart, length, step)
+    const end = resolveEnd(pEnd, length, step)
+    if (isNil(value)) return []
+    let range
+    if (step > 0) {
+      if (end <= start) return []
+      range = (function* () {
+        for (let i = start; i < end; i += step) yield i
+      }())
+    } else {
+      if (end >= start) return []
+      range = (function* () {
+        for (let i = start; i > end; i += step) yield i
+      }())
+    }
+    return Array.from(range, i => nextGetter(value[i]))
+  }
+}
+
+export const sliceNav = makeNav({
+  update,
+  get,
+})