I'd like to ask a question about JSON to get a feel for priorities of coders here
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If people didn't constantly reinvent the wheel, we'd still be using wooden wheels several feet in diameter. :laugh: Use the right wheel for the right job. Don't try to adapt to an existing wheel if it just doesn't do the job.
agreed!
Real programmers use butterflies
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I should add that I originally wrote it in C# and then ported it to C++ Why did I write it in C#? Because I didn't know about NewtonSoft's JSON on the day I wrote it and then when i found out about it it turns out NewtonSoft's pull parser sucks and is slow. I'm glad I did. People are religious about never reinventing the wheel, but it's not always such a bad thing - it depends on the wheel.
Real programmers use butterflies
honey the codewitch wrote:
People are religious about never reinventing the wheel, but it's not always such a bad thing - it depends on the wheel.
:thumbsup::thumbsup::thumbsup:
M.D.V. ;) If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about? Help me to understand what I'm saying, and I'll explain it better to you Rating helpful answers is nice, but saying thanks can be even nicer.
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I barely ever use JSON and have never written (nor am I likely to) a parser, but what I do know is that I can't answer a question like this without knowing the context. - Is it more important to be fast 100% of the time and permit errors 1% of the time, or to be 100% reliable at the cost of a few percentage points in speed? (i.e. how critical is the data, and how critical is speed? This is a pretty common trade-off) - Is the data coming from another system I / we have written, or a trusted partner, or from Joe Public? Is the data machine generated or hand-crafted?
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If you ever find yourself bulk loading JSON dumps into a database, you can do better. Hell, you could use my tiny JSON C# lib which is around here at CP somewhere.
Real programmers use butterflies
Tell me when you make a parser for XML. I'm loading 80 GB into a database every week, and XML (or rather the built in tools) seriously isn't made for that.
Wrong is evil and must be defeated. - Jeff Ello Never stop dreaming - Freddie Kruger
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Tell me when you make a parser for XML. I'm loading 80 GB into a database every week, and XML (or rather the built in tools) seriously isn't made for that.
Wrong is evil and must be defeated. - Jeff Ello Never stop dreaming - Freddie Kruger
will do!
Real programmers use butterflies
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Fortunately I'm not allowed to use third-party add-ins. I am awaiting access to the JSON support built into .net 4.7 and newer to see whether or not it can do what I require.
This one? What's next for System.Text.Json? | .NET Blog[^]
TTFN - Kent
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This one? What's next for System.Text.Json? | .NET Blog[^]
TTFN - Kent
I think so, but until I see it, I can't tell.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
I'm pretty trusting. When someone says they're going to give me JSON I assume they'll give me JSON. So I'd go for it and worry about validation when the party that should be giving me JSON isn't giving me JSON. So far that has worked pretty well. In practice, these kind of things rarely break. You either get JSON or no JSON at all, but rarely (or even never) a badly formed JSON.
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I'm pretty trusting. When someone says they're going to give me JSON I assume they'll give me JSON. So I'd go for it and worry about validation when the party that should be giving me JSON isn't giving me JSON. So far that has worked pretty well. In practice, these kind of things rarely break. You either get JSON or no JSON at all, but rarely (or even never) a badly formed JSON.
Best, Sander Azure DevOps Succinctly (free eBook) Azure Serverless Succinctly (free eBook) Migrating Apps to the Cloud with Azure arrgh.js - Bringing LINQ to JavaScript
I agree! :-D
Real programmers use butterflies
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Tell me when you make a parser for XML. I'm loading 80 GB into a database every week, and XML (or rather the built in tools) seriously isn't made for that.
Wrong is evil and must be defeated. - Jeff Ello Never stop dreaming - Freddie Kruger
I load 51GB of XML with what SSIS has built-in. It takes about twelve minutes. I load 5GB of JSON with my own parser. It takes about eight minutes. I load 80GB of JSON with my own parser -- this dataset has tripled in size over the last month. It's now taking about five hours. These datasets are in no way comparable, I'm just comparing the size-on-disk of the files. I will, of course, accept that my JSON loader is a likely bottleneck, but I have nothing else to compare it against. It seemed "good enough" two years ago when I had a year-end deadline to meet. I may also be able to configure my JSON Loader to use BulkCopy, as I do for the 5GB dataset, but I seem to recall that the data wasn't suited to it. At any rate, I'm in need of an alternative, but it can't be third-party. Next year will be different.
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So if it wasn't, you'd like to error as soon as you catch it, even if it meant a slower parse is what I'm hearing.
Real programmers use butterflies
yes
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why are you not using Newtonsoft? Not sure why you are re-inventing the wheel here. :confused: NuGet Gallery| Newtonsoft.Json 12.0.3[^]
Some people have to work on air gap networks, where you can not copy anything to the network. It comes configured with a couple of approved things like the operating system, and whatever comes bundled with say Visual Studio 2015, and that's it. Nothing else gets in. With good reason too, e.g. see supply chain poisoning like the recent SolarWinds incident.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
Since JSON is such a well defined construct simple parsers are very easy to write. I have a few. The nub is of course in 'a few'. It really falls into the case usage arena. If you know the data a quick regex parser will do. Regex parsers are fundamentally flawed though, and tend to fail on large data sets containing mixed characters (locale is a pain). So, well-formedness is largely there already. Two dimensional arrays only require a few lines of code. Multi dimensional arrays just a few more. Large unknown datasets across languages? Use someone else's library and save yourself time.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
Quote:
Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors
As with all input to your program, you validate on reception. All the other code that uses that input after that can then assume valid input and you can choose whatever shortcuts you want to on the assumption of valid input. Doesn't matter if the input is JSON, XML, key/value pairs from .ini files or tokens, you only validate it once on reception.
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Fortunately I'm not allowed to use third-party add-ins. I am awaiting access to the JSON support built into .net 4.7 and newer to see whether or not it can do what I require.
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
The spec is pretty clear, so correctness and errors are clear. To be fast is another matter, see fastJSON - Smallest, Fastest Polymorphic JSON Serializer[^] and GitHub - simdjson/simdjson: Parsing gigabytes of JSON per second[^]
Exception up = new Exception("Something is really wrong."); throw up;
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
A key question is what this parser will be used for. Is it for a hobby project or a production system? What would be the benefits of the higher performance? Will it be perceivable for human users? Will it save money by requiring less hardware? How much money? Is there an impact on the development effort? What is the impact on the resulting code in terms of maintainability? What would be the cost of choosing one option now and updating to the other option later? (is it a full rewrite? would it be simpler to go from A to B, or from B to A? etc.) What would be the code of implementing both options and letting the user (well, caller) decide which one to use? There are many things to factor in this decision. Maybe different developers will give different weights to these considerations, and inexperienced developers will overlook some or all of them, but I believe that for most developers the answer would (and should) be "it depends on the details of the situation".
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First of all this is a hypothetical. Second, hosting the .NET CLI in C++ just to use a .NET package from C++ to parse a little JSON seems heavy handed and horribly inefficient. Plus C# won't run on arduinos.
Real programmers use butterflies
honey the codewitch wrote:
hosting the .NET CLI in C++ just to use a .NET package from C++ to parse a little JSON seems heavy handed and horribly inefficient.
If you're using C++, why not use a C++ JSON library such as [Modern JSON](https://github.com/nlohmann/json), [RapidJSON](https://rapidjson.org/) or [simdjson](https://simdjson.org/)? Or if you do develop your own library, you might be interested to look at [simdjson's 'On Demand' parsing approach...](https://github.com/simdjson/simdjson/blob/master/doc/ondemand.md)
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
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honey the codewitch wrote:
hosting the .NET CLI in C++ just to use a .NET package from C++ to parse a little JSON seems heavy handed and horribly inefficient.
If you're using C++, why not use a C++ JSON library such as [Modern JSON](https://github.com/nlohmann/json), [RapidJSON](https://rapidjson.org/) or [simdjson](https://simdjson.org/)? Or if you do develop your own library, you might be interested to look at [simdjson's 'On Demand' parsing approach...](https://github.com/simdjson/simdjson/blob/master/doc/ondemand.md)
Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p
They use too much memory and can't target IoT. of them simdjson shows the most potential but it still isn't about 71 bytes to do an episodes query off of a tmdb.com show data dump
Real programmers use butterflies
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Let's say you wanted to write a fast JSON parser. You could do a pull parser that does well-formedness checking Or you could do one that's significantly faster but skips well formedness checking during search/skip operations, which can lead to later error reporting or missed errors You can't make an option to choose one or the other, but you can avoid using the skip/search functions that do this in the latter case. Which do you do? Are you a stomp-the-pedal type or a defensive driver? (Seriously, this is more about getting a read of the room than anything - I want a feel for priorities)
Real programmers use butterflies
Stability over performance!
