ordered-map

Immutable JS OrderedMap: Insert a new entry after a given Key

由 99封情书 提交于 2021-02-08 07:51:14
问题 I have an Immutable OrderedMap as follows: pairs: Immutable.OrderedMap({"Key1":"Value1","Key2":"Value2","Key4":"Value4"}) I need to insert ["Key3":"Value3"] after ["Key2":"Value2"] dynamically. I thought pairs.MergeIn(['Key2'],OrderedMap({"Key3":"Value3"})) will serve the purpose but not working. I tried const newPairs=Immutable.OrderedMap(); newPairs.forEach(function(value,key,map)){ if(key=="Key4") newPairs.set('Key3','Value3') newPairs.set(key,value') }); But I know it's a stupid code

Why there is no ordered hashmap in Redis?

由 我只是一个虾纸丫 提交于 2021-02-07 09:58:26
问题 Redis Data types includes sorted set and other necessary data-structures for key-value storage. But I wonder why it doesn't have any sorted map like Java's TreeMap or C++'s std::map . I think the underlying data-structure would be mostly similar of sorted set as both are supposed to be balanced binary search tree. There must be some use-cases where we have to store key-value pair in specific order according to key. But current sorted set only serves the purpose of storing key according to

Why there is no ordered hashmap in Redis?

由 南笙酒味 提交于 2021-02-07 09:58:22
问题 Redis Data types includes sorted set and other necessary data-structures for key-value storage. But I wonder why it doesn't have any sorted map like Java's TreeMap or C++'s std::map . I think the underlying data-structure would be mostly similar of sorted set as both are supposed to be balanced binary search tree. There must be some use-cases where we have to store key-value pair in specific order according to key. But current sorted set only serves the purpose of storing key according to

Why there is no ordered hashmap in Redis?

由 假如想象 提交于 2021-02-07 09:57:00
问题 Redis Data types includes sorted set and other necessary data-structures for key-value storage. But I wonder why it doesn't have any sorted map like Java's TreeMap or C++'s std::map . I think the underlying data-structure would be mostly similar of sorted set as both are supposed to be balanced binary search tree. There must be some use-cases where we have to store key-value pair in specific order according to key. But current sorted set only serves the purpose of storing key according to

Parsing YAML, get line numbers even in ordered maps

由 ◇◆丶佛笑我妖孽 提交于 2019-12-24 07:46:18
问题 I need to get the line numbers of certain keys of a YAML file. Please note, this answer does not solve the issue: I do use ruamel.yaml, and the answers do not work with ordered maps. #!/usr/bin/env python3 # -*- coding: utf-8 -*- from ruamel import yaml data = yaml.round_trip_load(""" key1: !!omap - key2: item2 - key3: item3 - key4: !!omap - key5: item5 - key6: item6 """) print(data) As a result I get this: CommentedMap([('key1', CommentedOrderedMap([('key2', 'item2'), ('key3', 'item3'), (

Scala Map implementation keeping entries in insertion order?

由 ◇◆丶佛笑我妖孽 提交于 2019-12-17 06:14:32
问题 In Java, I use LinkedHashMap for this purpose. The documentation of Java's LinkedHashMap is very clear that it has "predictable iteration order" and I need the same in Scala. Scala has ListMap and LinkedHashMap , but the documentation on what they do exactly is poor. Question: Is Scala's LinkedHashMap or ListMap the implementation to use for this purpose? If not, what other options are available besides using the Java's LinkedHashMap directly? 回答1: From the LinkedHashMap Scaladoc page: "This

Scala Map implementation keeping entries in insertion order?

由 拟墨画扇 提交于 2019-11-26 22:43:02
In Java, I use LinkedHashMap for this purpose. The documentation of Java's LinkedHashMap is very clear that it has "predictable iteration order" and I need the same in Scala. Scala has ListMap and LinkedHashMap , but the documentation on what they do exactly is poor. Question: Is Scala's LinkedHashMap or ListMap the implementation to use for this purpose? If not, what other options are available besides using the Java's LinkedHashMap directly? From the LinkedHashMap Scaladoc page: "This class implements mutable maps using a hashtable. The iterator and all traversal methods of this class visit
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