Questions tagged [parsing]
Questions about built-in/custom parsers or parsing techniques.
94 questions
2
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1
answer
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Finding position of corresponding parentheses in expression
Suppose we have an expression in InputForm as a string. The task is to find position of corresponding parentheses. For example parenthesis at position ...
- 32.8k
1
vote
4
answers
187
views
Parse data with patterns
If
arr = {1, {2, 3}};
we get {{2, 3}} from
Cases[arr, {a___, b___} :> {a, b}]
But if
<...
- 2,590
6
votes
2
answers
220
views
Is there a system option to make Mathematica generate syntax error when reading code from file which has red syntax warning in frontend?
I type some equations from text books into database, which later read from Mathematica to solve.
Since I do this manually, sometimes I make mistakes where I type ...
- 156k
4
votes
1
answer
189
views
Is it possible to improve efficiency of the function?
I have the following function scriptQ to check whether an expression is a "script" or not.
This function is frequently called by others, so I need to ...
- 3,467
5
votes
1
answer
241
views
Validate `Box` grammar, is it possible?
Is it possible to validate grammar related to Box formed expression (RowBox, FractionBox, ......
- 4,435
1
vote
1
answer
147
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Why does `a&/.b` parse as `(a&)/.b` if `a&` has lower precedence than `x/.y`? [closed]
The documentation says that expr& has lower precedence than expr1 /. expr2. Thus, parsing should start from operators with ...
- 175
2
votes
1
answer
119
views
Why does the console REPL parse input differently from ToExpression?
In the console REPL, we can see that input is parsed in a certain way, that is not equivalent to simply calling ToExpression on the input string. From math.exe using Mathematica 13.1:
...
- 21
0
votes
0
answers
151
views
Parsing of WL code
Upon opening a .wl file someone send me I noticed that about 20 seconds were spend parsing the file. Sometimes it spends less time doing so for much bigger files. Upon looking up the term "...
- 1,783
1
vote
2
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123
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Parsing data from site
I try parse hub titles and links from this site: https://habr.com/en/hubs/, but code returns empty list. Can not understand why.
...
- 13
2
votes
0
answers
1k
views
Input subscripts in Wolfram Cloud
I would like to input "rendered" subscripts in Wolfram Cloud, without having to verbosely type Subscript[a, b]. The local notebook shortcut is ...
- 1,310
3
votes
2
answers
291
views
Custom bracket parser
I have a function $F$ taking arbitrarily many arguments from ${a,c,z}$ where practically (technically it isn't) $a$ works as an opening bracket and $z$ as a closing. ($c$ stands for a value.) Double ...
- 1,243
18
votes
2
answers
754
views
How to create a CLI for Wolfram language scripts?
Former question: How to use wolframscript to develop flexible command-line tools?
I am currently changing a notebook into a wolframscript for a "production" environment,
where I plan to ...
- 926
16
votes
1
answer
642
views
How can I ingest and analyze benchmark results posted at MSE?
How can I ingest Mathematica / WL benchmark results posted at Mathematica Stack Exchange (MSE), like the ones posted here?
Assumptions:
There are multiple answers with benchmarks posted
The ...
- 38.5k
1
vote
0
answers
65
views
Distinguishing function calls from multiplication when importing LaTeX via ToExpression and TeXForm
I'm trying to parse a LaTeX representation of a Desmos calculator (like this one) via Mathematica.
Desmos exposes a JSON representation of its calculators, including a LaTeX representation of ...
- 111
1
vote
1
answer
118
views
Parse coefficients from a Resolve output
I have a huge output from Resolve (quantifier elimination) that I must parse to extract the coefficients as numbers. Take for instance something that looks like ...
- 125
1
vote
2
answers
631
views
How to extract data and attribute data from an XMLElement
I am trying to write a function to extract both the data and the attribute data from an XMLElement in the same pass. I have followed the examples from Mathematica's Transforming XML tutorial and the ...
- 317
2
votes
1
answer
470
views
Reading information from a Portable Executable (.exe)
I want to extract information from executable files, such as the names and sizes of sections, symbols, etc. The Wikipedia article has a diagram showing the layout of a PE. See also this diagram
It ...
- 26.3k
6
votes
4
answers
772
views
What is the best way to parse differential equations and boundary conditions to a custom function?
I have written a method to turn systems of linear differential equations into matrix equations (discretisation). This handles boundary conditions using the row replacement method.
At the moment, I ...
- 525
10
votes
2
answers
397
views
Removing banal words from a list
NB: I am aware of the DeleteStopwords symbol.
I want to remove from a list of words the ones that are likely to be more banal. So for instance if we have
...
- 1,973
14
votes
2
answers
281
views
Repeated string pattern: difference between the FrontEnd and WolframScript?
This code works fine in a string based interface like WolframScript or Mathematica Kernel.
Run this through a string based interface
...
- 51.3k
4
votes
3
answers
169
views
Subsequence Search
I need to parse some xml code. I need to extract some values withing pattern elements. I made an example of my trouble.
Here is some complicated xml list:
...
- 71
3
votes
0
answers
243
views
Slight loss of precision when parsing JSON
Exporting to JSON is working well for me under 11.3. The issue present in previous versions seem to be solved:
...
- 8,996
11
votes
1
answer
235
views
Lexical scanning and parsing in a toy language
I'm trying to do lexical scanning and parsing in a toy language. One with just functions (of the form $f(a,\,b,\,c,\,...)$, ended with semicolons) and special tokens (such as ...
- 3,734
2
votes
0
answers
96
views
Confusing behavior for GrammarRules and GrammarApply
I have been experimenting with GrammarRules in an attempt to create a parser for text downloaded from the web. I have been using Interpreter to help understand the behavior of GrammarApply. Here is a ...
- 711
11
votes
1
answer
138
views
Precedence of cell group tokens over package's expressions
Bug introduced in V10.4 or earlier and persisting through V11.3
[CASE:4072996]
...
- 139k
9
votes
4
answers
3k
views
How to convert a string having nested parentheses into an expression?
I am a Wolfram Language/Mathematica beginner and trying to convert STEP ISO10303 commands into geometrical regions.
A simple command looks like
...
- 121
6
votes
1
answer
1k
views
How to determine if RHS of first order ODE is separable or linear or neither? Parsing problem
Introduction
This is really a parsing question. But the context is that
given the right side of first order ode, I want to automatically
determine the class of the RHS. It can be either separable, ...
- 156k
20
votes
1
answer
594
views
Is building an event-based parser possible/reasonable in Mathematica (WL)?
Too long? Go to Problems section
Background
I like to learn by doing small, sometimes artificial, projects. Among other things I had 'parsers', and 'stream methods / streams in MMA' on my to learn ...
- 139k
12
votes
3
answers
597
views
Markdown parser in Mathematica
Is there already a markdown to XML parser implemented in Mathematica? I wrote a one for my pelican rewrite, but realized I should have asked here first. Mine is almost certainly faulty in a few major ...
- 48k
7
votes
2
answers
555
views
Getting the front sign of an expression. Positive or negative for formatting only
This is for the purpose of generating a string (actually it will Latex string, but that is not important).
I need to generate string as
...
- 156k
6
votes
1
answer
137
views
Can we make preread replacements in an *.m* file before being run?
This the second question of (152743), the preamble of which is reproduced here:
Those who don't have/prefer the front end of Mathematica will either use a plain ASCII editor to write a script in an <...
- 19.9k
5
votes
1
answer
164
views
Can we make new definitions for InputForm in packages?
Those who don't have/prefer the front end of Mathematica will either use a plain ASCII editor to write a script in an .m file or just use Mathematica directly from ...
- 19.9k
1
vote
0
answers
128
views
Scraping XML Paragraphs with URLs
I've been working on scraping an article from CNBC. The link is here
I want to scrape the main body, and the code I have so far is this:
...
- 647
1
vote
1
answer
281
views
Ugly Gaussian symbolic integration, how to extract coefficients and exponent argument?
I have a very ugly function with 157 terms that I want to integrate over three variables. Each term is a Gaussian integral in those variables multiplied by a polynomial in the variables. However, in ...
- 175
3
votes
1
answer
660
views
Pulling Out Values from JSON Association
Having a bit of trouble pulling a value out of a JSON Association here. I am scraping this website: http://www.msn.com/en-us/money/stockdetails/history/fi-126.1.BY.NYS
I want to scrape the closing ...
- 647
0
votes
0
answers
538
views
HTTP Status Code 403
I'm working with some scraping and have run into a bit of a problem. The website I am scraping is this: https://seekingalpha.com/symbol/CRM/stocktalks
I am essentially trying to scrape the "stock ...
- 647
1
vote
1
answer
128
views
Extracting Certain Areas of JSON
I've been working with some web scraping and have run into a wall. The website I'm working with is this: https://seekingalpha.com/symbol/TWLO/stocktalks
I am trying to scrape all of the "stock talks" ...
- 647
2
votes
1
answer
634
views
Parsing and Extracting XML Content
I've run into a little question while trying to parse XML. This seems like a rather simple task, but for the life of me I cannot figure it out. I pull up the XML of the website using the following ...
- 647
2
votes
2
answers
675
views
Parse command line arguments
I have been trying to parse command line arguments.
There are a couple of types of options.
1. Mandatory
2. Optional
3. Alternative
There are built-in/3rd ...
- 3,258
6
votes
0
answers
166
views
Infix non-ASCII operator needs a space to be parsed correctly in a script
Bug introduced in 9.0 or earlier and persisting through 11.1
First off:
...
- 8,856
9
votes
3
answers
4k
views
3
votes
0
answers
40
views
Unexpected behaviour with WordSeparators and Read [duplicate]
I am confused about how Read separates elements.
The following all work fine:
...
- 239k
5
votes
1
answer
283
views
Context inside Do[...]-loop
Consider the following code:
Begin["mycontext`"];
myvar = 7;
Print[Context[]];
Print[Context[myvar]];
End[];
with the output
mycontext`
mycontext`
Now ...
- 517
3
votes
2
answers
1k
views
Reading a text file and parsing only the text between two delimiters
How are you?
I'm a chemist with almost no experience with Mathematica, but I'm thinking of using it as a tool for my Ph.D in Computational Chemistry. My Quantum Chemistry software (ORCA) generates a ...
- 193
1
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2
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283
views
How is a single tilde parsed?
How is a~b parsed and evaluated? I would expect an error, but it goes through without any complaints, yielding no apparent output. At first I thought it evaluated ...
- 3,503
4
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1
answer
113
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How do I import a Dataset that contains lists?
The very first example in the Dataset documentation is the following:
...
- 93
3
votes
1
answer
156
views
How to use MakeExpression for single characters
Here is code that I thought would make the front end parse f as BigFunction:
...
- 19.9k
11
votes
4
answers
2k
views
How to get the longest bracket pairs from a string
In C#, we can use regular expression to do some balancing groups, like we can get
{<aa <bbb> <bbb> aa>, <<dfa>a>}
from
...
- 27.8k
19
votes
4
answers
968
views
Is it important that the front-end has a built-in parser?
The Notebook interface has a parser that seems aware of all operator-precedences, allowing us to step through the expressions (rather: Box-) hierarchy with Ctrl+.
This is extremely convenient, saving ...
- 5,829
6
votes
1
answer
124
views
Can Read[] apply a custom function automatically to the read values?
Read[stream, Number] will return a single read number. We can use a number of standard, documented types instead of Number, ...
- 239k