Analyzing (un)structured data to convert it into a structured, normalized format.

learn more… | top users | synonyms (1)

2
votes
0answers
146 views

Implementing semantic actions in table driven predictive parsing

When doing table driven predictive parsing on an LL(1) grammar, (as explained in good detail here for example), how can we augment the algorithm to allow processing of semantic actions while doing the ...
4
votes
2answers
272 views

Should I commit my generated parser to source control?

I'm using a parser generator to build a compiler. Should I commit the source files produced by the parser generator? I want to commit them to avoid a dependency on the parser generator during the ...
2
votes
4answers
213 views

The right place to embed a parser : Server or the Client?

I'm writing a database management software. It has a client-server architecture where the server has the piece of code to store and retrieve. The client has to get the input from the user, connects to ...
1
vote
2answers
288 views

How would my custom language be categorized?

I'm developing my own scripting language to solve some unique challenges for a project. The language takes source code and converts the contents into tokens, and then a command factory is used to ...
-3
votes
1answer
222 views

Best Object Oriented way of parsing a model with several fields(>50) and with null checks

I have a JSON-based data which contains many fields from a particular model. Any value from the list of fields can be null. I am trying to find the best object oriented way of parsing it and also it ...
3
votes
3answers
254 views

What is the proper way to distinguish between keywords and identifiers?

I'm aware that most modern languages use reserved words to prevent things like keywords from being used as identifiers. Reserved words aside, let's assume a language that allows keywords to be used ...
3
votes
1answer
1k views

Any ASN.1 parsers written completely in managed code & safe from buffer overflows

ASN.1 is a data format used on HTTPS certificates, and various other critical pieces of infrastructure. I need to analyze some potentially hostile ASN.1 data, and want to ensure my code is safe from ...
4
votes
2answers
536 views

Learning YACC nowadays, does it make sense? [closed]

I have a huge project that is using YACC and I would need to fix a bug in it. I might ask someone else who wrote that to fix it but I'm interested in how compilers work. Does it make sense to learn ...
1
vote
1answer
331 views

PHP Simplest XML tokenizer for string processing?

I need to do some text processing tasks with short XML fragments. The section "details" shows an example... My solution is to use a tokenizer based on regular expresions, but it is not elegant and not ...
1
vote
2answers
107 views

Creating documents from snippets [closed]

From time to time I create whole documents (e.g. XML or proprietary) programmatically. If it easy enough, I just write something like stringbuilder.append("<blah>"); ...
0
votes
1answer
828 views

Why nginx's http parser doesnt use regular expressions?

I see the http parser written by Igor Sysoev for nginx does not use regular expressions https://github.com/joyent/http-parser What could be the main reason for such design decision? I guess I could ...
12
votes
2answers
874 views

What does scannerless parsing have to do with the “Dangling Else Problem”?

I do not understand this sentence from the Wikipedia article on the Dangling Else problem: [The Dangling Else problem] is a problem that often comes up in compiler construction, especially ...
8
votes
3answers
507 views

What the correct algorithm to invert italics in a mixed text?

The question motivations was depicted in the section below. There are many ways to make text italic, so, perhaps, there are more than one good "swap italics algorithm". The problem reveals some ...
33
votes
6answers
2k views

Why was strict parsing not chosen for HTML?

I am pretty much unaware about the detailed computing history that surrounds internet but it has always made me think why strict parsing was not chosen when creating HTML. Browsers accept any rubbish ...
3
votes
1answer
253 views

Chosing a parser for a code beautifier

I'm in the planning stage of making a code beautifier (similar to AStyle or Uncrustify) - originally I was going to just contribute to one of those projects, but reviewing their source led me to the ...
1
vote
4answers
388 views

Is it possible to create a single tokenizer to parse this?

This extends off this other Q&A thread, but is going into details that are out of scope from the original question. I am generating a parser that is to parse a context-sensitive grammar which can ...
-3
votes
2answers
285 views

What is the name of a grammar which can change its tokenizer in mid parse?

I was creating a language and discovered that my language tokenizer would have to change depending where in the parse it is. I.e. abc[1] would be parsed as 4 tokens (abc, [, 1, ]), where as { abc[1] ...
10
votes
3answers
1k views

Writing a Compiler Compiler - Insight on Use and Features

This is part of a series of questions which focuses on the sister project to the Abstraction Project, which aims to abstract the concepts used in language design in the form of a framework. The ...
0
votes
0answers
72 views

Considerations for beginning work on a unified search [on hold]

I have become interested in creating a unified search for a corporate asset management database. My goal is to allow users to submit queries like: stuff in building 3210 stuff in building 3210 owned ...
1
vote
2answers
173 views

Resources for writing a parser combinator library [closed]

I often use parser combinator libraries, but I've never written one. What are good resources for getting started? In case it matters, I'm using Julia, a functional (but not lazy) language.
1
vote
2answers
325 views

Should I use a formal grammar for my interpreted scripting language

I have a scripting engine I just published as an open source project. It's been sitting on my harddrive waiting for about a year. My engine of course isn't complete in any way, but it does work for ...
2
votes
1answer
409 views

How to choose a proper parser generator for PHP

Some programmers avoid regexes in some situations (see this popular @nickf comment), perhaps using a parsing framework such as Lex/Yacc. Others prefer to stay within PHP, perhaps using regular ...
14
votes
3answers
5k views

Implementing the Visitor Pattern for an Abstract Syntax Tree

I'm in the process of creating my own programming language, which I do for learning purposes. I already wrote the lexer and a recursive descent parser for a subset of my language (I currently support ...
1
vote
2answers
156 views

How are line/column position data dealt with in parser combinator libraries?

I'm building a parser using a parser combinator library. I need to keep track of where AST nodes started and ended in the textual input -- line and column numbers. How is this problem approached ...
8
votes
3answers
7k views

Generic file parser design in Java using the Strategy pattern

I am working on a product in which the responsibility of one of the modules is to parse XML files and dump the required content in a database. Even though the present requirement is only to parse XML ...
1
vote
2answers
153 views

Creating a text input simplifaction tool

I have been working on a project for several months now to write a web-based tool that will help me at work. I work at a call center and the CRM software that is used is wretched, we basically have to ...
2
votes
1answer
242 views

Practical reference for learning about graph reduction

Are there any practical references (with actual examples) for getting started implementing a small, lazy functional programming language with graph reduction? A reference that included the lexing and ...
8
votes
4answers
792 views

Using a “dead man's switch” to manage time-sensitive code

In our software environment, we often run a/b tests, as is probably good practice. However, our environment is set up such that, in very short order, the code starts to become very crufty with dead ...
3
votes
1answer
249 views

Showing a grammar is ambiguous

I have the following question taken from a compilers course exam: Show that the following grammar is ambiguous. S = XcY X = a Y = b | Z Z = bW W = d | ϵ I drew the following tree: Am I correct ...
0
votes
2answers
253 views

How to extract operators from the grammar productions for conflict resolution in LALR parser?

Is there some standardized or widely accepted algorithm for picking up operators in shift/reduce conflicts in LALR parser? The question is naive, my problem is not with implementing my solution, but ...
2
votes
1answer
288 views

REST efficiency on count and sum methods

For example, if I have a Customer Transactions Table and I create a REST for it. The fields are: date, description, and total_amount. I am trying to figure out which one is much more efficient when ...
7
votes
2answers
644 views

Language parsing to find important words

I'm looking for some input and theory on how to approach a lexical topic. Let's say I have a collection of strings, which may just be one sentence or potentially multiple sentences. I'd like to ...
7
votes
3answers
816 views

What is a real-world use case of using a Chomsky Type-I (context-sensitive) grammar

I have been having some fun lately exploring the development of language parsers in the context of how they fit into the Chomsky Hierarchy. What is a good real-world (ie not theoretical) example of a ...
1
vote
2answers
132 views

Extracting useful information from free text

We filter and analyse seats for events. Apparently writing a domain query language for the floor people isn't an option. I'm using C# 4.0 & .NET 4.0, and have relatively free reign to use ...
2
votes
1answer
805 views

How to add precedence to LALR parser like in YACC?

Please note, I am asking about writing LALR parser, not writing rules for LALR parser. What I need is... ...to mimic YACC precedence definitions. I don't know how it is implemented, and below I ...
0
votes
1answer
142 views

How lookaheads are propagated in “channel” method of building LALR parser?

The method is described in Dragon Book, however I read about it in ""Parsing Techniques" by D.Grune and C.J.H.Jacobs". I start from my understanding of building channels for NFA: channels are built ...
1
vote
1answer
214 views

How to read reduce/shift conflicts in LR(1) DFA?

I am reading an explanation (awesome "Parsing Techniques" by D.Grune and C.J.H.Jacobs; p.293 in the 2nd edition) and I moved forward from my last question: How to get lookahead symbol when ...
3
votes
2answers
2k views

How to get lookahead symbol when constructing LR(1) NFA for parser?

I am reading an explanation (awesome "Parsing Techniques" by D.Grune and C.J.H.Jacobs; p.292 in the 2nd edition) about how to construct an LR(1) parser, and I am at the stage of building the initial ...
2
votes
1answer
308 views

LL(∞) and left-recursion [closed]

I want to understand the relation between LL/LR grammars and the left-recursion problem (for any question I know parcially the answer, but I ask them as I don't know nothing, because I am a little ...
3
votes
1answer
1k views

Extracting color profile information from JPEG files

I'm trying to look up info about reading JPEG's color profile info and to my surprise there's very little open specific how-to information on that regard, but rather lots of general explanation on ...
8
votes
4answers
263 views

How should I implement a command processing application?

I want to make a simple, proof-of-concept application (REPL) that takes a number and then processes commands on that number. Example: I start with 1. Then I write "add 2", it gives me 3. Then I ...
13
votes
5answers
426 views

How can I best manage making open source code releases from my company's confidential research code?

My company (let's call them Acme Technology) has a library of approximately one thousand source files that originally came from its Acme Labs research group, incubated in a development group for a ...
5
votes
1answer
471 views

Scripting custom drawing in Delphi application with IF/THEN/ELSE statements?

I'm building a Delphi application which displays a blueprint of a building, including doors, windows, wiring, lighting, outlets, switches, etc. I have implemented a very lightweight script of my own ...
3
votes
1answer
198 views

What does it mean that StAX parsers aren't complete or correct?

I've been browsing the net and found theses two slides on site of XOM (XML object model): slide1 slide2 Where they refer to SAX(push) and StAX(pull) parsers. So I'm wondering, what does it mean ...
17
votes
4answers
1k views

Generic rule parser for RPG board game rules - how to do it?

I want to build a generic rule parser for pen and paper style RPG systems. A rule can involve usually 1 to N entities 1 to N roles of a dice and calculating values based on multiple attributes of an ...
8
votes
2answers
751 views

Persisting natural language processing parsed data

I've recently started experimenting with natural language processing (NLP) using Stanford's CoreNLP, and I'm wondering what are some of the standard ways to store NLP parsed data for something like a ...
3
votes
3answers
465 views

design for a parser to handle very large files

I have written a program which records protocol messages between an application and a hardware device which matches each application request with each hardware response. This is so that I can later ...
1
vote
1answer
250 views

Does JAXP natively parse HTML?

So, I whip up a quick test case in Java 7 to grab a couple of elements from random URIs, and see if the built-in parsing stuff will do what I need. Here's the basic setup (with exception handling etc ...
10
votes
5answers
5k views

Can the csv format be defined by a regex?

A colleague and I have recently argued over whether a pure regex is capable of fully encapsulating the csv format, such that it is capable of parsing all files with any given escape char, quote char, ...
3
votes
3answers
586 views

How do I translate user input into a fictitious language?

For experimental reasons, I am trying to convert user input into a fictitious language. All of the translation can be 1:1. I would prefer if I could accomplish this with PHP. Should I use gettext ...