Questions tagged [grammar]
A formal grammar is a set of production rules that describe how to form strings of valid syntax. Formal grammars are most often used to specify the syntax of a programming language.
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BNF for a number
I'm looking to learn and practice parsing, and so I have started with writing an EBNF for a number (using the python interpreter as an example of possible inputs).
Here is what I have so far (also ...
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1answer
166 views
Is there a better way to parse this data file?
I have a text data file in SPWLA format; I cannot find a specification for it. It contains physical measurements and/or rock descriptions from wellbore core samples. It's fairly gross. The example ...
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3answers
854 views
Recursive Descent Parser Implementation for a Recursive Language
I'm writing toy parsers for toy languages to understand how parsers work.
Assuming a language as follows (in sketchy EBNF patois)
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2answers
102 views
Removing commented dead code without removing the legitimate comments
This question is the real question asked on StackOverflow. I'm here to review my answer and see how can I optimize it.
Here is the answer text:
This is a basic approach, but it proposes a proof of ...
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1answer
175 views
Parsing a C++ function declaration with Perl 6 grammar
I wrote a Perl 6 grammar to parse a C++ function. My final goal would be to parse an entire header. The aim is not to correct C++ syntax errors, but to parse valid C++.
Do you have some advice or ...
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0answers
352 views
Eliminating chain rules from context-free grammars
I'm writing a small C program for elimination of chain rules from a context-free grammar.
My idea is to rewrite the rules of the grammar in a specific useful order: making groups of productions that ...
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0answers
47 views
Parsing λ-terms using a very simple grammar
This is my first Rust program. It parses a string into a λ-term using a very simple grammar.
Please evaluate style and use of ownerships / borrowing.
...
4
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0answers
56 views
Correct user typos in a C source file using Perl 6 grammar
To learn about Perl 6 grammars, I created a simple parser for C source files. Note that this is a constructed example motivated by this question. The point is to parse a C source file and correct user ...
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0answers
33 views
dyon vim syntax plugin
I recently made vim-dyon which is a syntax highlighter and indenter for the dyon programming language. There are probably some issues with being absolutely correct (since I am not too familiar with ...
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1answer
93 views
Syntax for a simple scripting language [closed]
I'm creating a small simple scripting language for fun and as a learning exercise. For the first iteration I want it to be very simple:
C-style syntax
Functions are defined globally as in C, no ...
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2answers
1k views
Regular expression to identify java function
I am trying to identify a java function block addition in a diff file (new line start with + in diff).
For that I am using regular expression.
It is working fine, ...
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1answer
398 views
PEG.js grammar for a simple programming language
I'm trying my hand at developing a compiler and have written a peg.js grammar for a simple programming language. A sneak peak at the grammar:
...
2
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1answer
62 views
Overly large syntax highlighting function
I've written a text editor in Rust.
make_highlights is responsible for syntax highlighting. It takes a Row, which is just a ...
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1answer
89 views
Grammar for a custom language called Elegance
I'm working on my own custom language called Elegance. This is my first grammar, and I'm looking for help with:
Readability
Expressiveness/DRY code (Can I easily reuse rules/tokens?)
Edge cases (Is ...
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1answer
1k views
Checking proper English sentences of user's input with grammar using C++
Write a program that checks if a sentence is correct according to the
“English” grammar in §6.4.1. Assume that every sentence is terminated
by a full stop (.) surrounded by whitespace. For example,...
3
votes
1answer
167 views
Converting to and from Roman numerals
I wrote a simple Boot script for converting to and from Roman numerals using instaparse. Here's my EBNF grammar (roman.bnf):
...
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1answer
65 views
Haskell tool for find @SuppressWarnings in Java source code
I put together a little tool for finding where people have suppressed warnings, and to see if they have commented why. Its in Haskell for fun and some practice. Its split into two files, the thinking ...
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1answer
444 views
Grammar lexer in C++
Here is a lexer for a grammar I'm designing. After benchmarking with 1MB files and having several iterations of the lexer, I found that coping the file being read into a buffer and lexing that buffer ...
2
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1answer
175 views
L-Systems in OCaml
For reference: L-system
I'm mostly looking for general style stuff here and in particular:
if my type parameters are too crazy — I wanted two parameters so that variables and constants could have ...
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2answers
6k views
Yet another lexical analyser
The following program is a lexical analyser for a simple and small grammar.
Please read my code and answer me these questions:
Is my code easy to understand?
Is my code well organized?
Are there ...
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1answer
1k views
FIRST and FOLLOW sets calculator in Haskell
I found myself wanting to brush up on some notions about parsers and grammars and, at the same time, to exercise my Haskell - I am a Haskell newbie; moreover, I haven't touched the language at all in ...
4
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1answer
226 views
Syntax highlighter for HTML and PHP
I've created a JavaScript application to highlight the syntax of HTML and PHP. I know a lot of syntax highlighter are available nowadays, I just created to extend my knowledge in JS and regular ...
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3answers
2k views
AST implementation
I'm new to C++, so I'm trying to learn the language by implementing all the type systems and languages in Pierce's Types and Programming Languages. My first attempt starts at the very beginning and ...
10
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1answer
442 views
Unit test code for Antlr Grammar
I'm working on a grammar for the Visual Basic for Applications (VBA) programming language. I've discovered a way to make assertions about how a parse tree should be generated by using the Antlr ...
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1answer
237 views
Reference Implementation for Honey Badger programming language
I've been working on my own dynamically-typed, dynamically-scoped, imperative programming language called Honey Badger and feel that it's reached a stable enough state that I want someone else's eyes ...
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1answer
369 views
Expressing Rebol Dates in EBNF
I'm looking to define the Rebol date format in EBNF notation. I'd like as best as possible to only define valid dates—at least those that are valid in Rebol at the moment:
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2answers
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1answer
1k views
PEG.js grammar for parsing CSS selectors
I have a library that's parsing some expressions, part of which is a CSS selector. More accurately, it's a jQuery-compatible selector. The selector itself is opaque to my library - I don't need to ...
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1answer
173 views
Expanding a synchronous grammar
Background:
A synchronous grammar is a like two context-free grammars connected in parallel. It is used for translation. For example, here is a small synchronous grammar that can be used for ...
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1answer
451 views
Parsing a basic scripting language
I'm working on writing a scripting language with ANTLR and C++. This is my first actual move from ANTLR grammars into the C++ API, so I'd like to know if this would be a good way to structure the ...
