Questions tagged [antlr4]
Version 4 of ANother Tool for Language Recognition (ANTLR), a flexible lexer/parser generator. ANTLR4 features an enhanced adaptive LL(*) parsing algorithm, that improves on the simpler LL(*) algorithm used in ANTLR3.
antlr4
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How to express a "call form" expr syntax like 'func arg arg' in Antlr4?
Consider my simple grammar, skipping the lexer here:
expr:
expr expr+ # CallFormExpr // ⬅ the question here!
| L_PAREN expr R_PAREN # ParensExpr
| ...
- 2,175
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How to exclude specific characters from a `\p{..}` unicode set in an Antlr4 Lexer?
In the language I'm grammaring here, I want to allow custom operator definitions whose identifiers fall into the Unicode categories S,P,Me (symbols, punctuations, enclosing-marks) but exclude the ...
- 2,175
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antlr case insensitivity is being ignored [duplicate]
For some reason the letter fragments defined in a case-insensitive manner are still case-sensitive:
grammar filter;
query: expression? EOF;
expression : field ...
- 1,536
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How to solve parsing of a grammar with ambigous syntax, parser matches more than one rule
I'm trying to write a parser for a maxscript that has several ambiguous statements.
Example grammar:
program: expr* EOF ;
expr: simple_expr | case_expr ;
// fn_call must be first, if not, the ...
- 11
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Contextual awareness for Auto Completion using antlr4-c3 [SQL] [duplicate]
I am trying to write Auto-completion for SQL-Queries. I want to recommend contextual Tables.
The query might be: Select from test with the caret being between select and from. I would like to only ...
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How does Antlr4 support both integers and decimals in terms of lexicon? [duplicate]
I wrote a case study that can perform conventional mathematical operations on integers and decimals
grammar Calculation;
calculation: expr EOF;
// Parser rules
expr: expr (ADD|SUB) expr
| expr (...
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How can I get the the unrecognized Token in an ANTLRErrorListener for a Lexer?
I have a lexer, generated with ANTLR. What I try to achive is to handle an error during lexing in case of an not recognized token.
How can I get only the character causing this error?
lexer....
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Parsing an array with specific amount of elements
I've recently tried to parse an array with a fixed size in antlr4:
array[int size]
: {size > 0}? thing array[$size - 1]
|
;
This allows me to have arrays with a size determined by my ...
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How to build the antlr grammar provided?
I would like to build a cpp parser using cpp and I'm using ANTLR4. I notice there is this 'grammar' section from the official github antlr grammar github and I've downloaded it. While opening the CPP ...
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Antlr grammars that generate actual class inheritance
Need to know, is it possible to generate parsers, lexers, listeners, etc, by importing subset-grammars? I see that the supergrammar subgrammar pattern is possible, but I'm not sure I see a true class ...
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How to resolve the mistmatched input 'token' expecting 'LEXER_RULE'
I have the following grammar defined in ANTLR4 (g4):
grammar SimpleExpr2;
expr: entityName '(' paramList ')' SEMICOLON;
entityName: ENTITY_NAME;
paramList: param (SEPARATOR param)*;
param: ...
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ANTLR4 GUI parse tree visualisator indefinitely runs without throwing an exception nor producing results
I tried to run the ANTLR4 visualization interpreter from this class with the example grammar description and program code from the antlr4-tools.
However with the latest antlr4 release (4.13.1) it runs ...
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Extracting SQL JOIN condition column names not working with Antlr using Python
The code below is my attempt to identify join relationships between tables in a Oracle database.
The idea is to build a map of joins to help identify implicit FK relationships.
In the code below I use ...
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Issues Parsing format Statements with Labels in Fortran 2023 Grammar Using ANTLR4
I have developed a Fortran 2023 grammar using ANTLR4, and the grammar is available on my GitHub repository.
While parsing the code, I encounter an issue with Format statements. According to the ...
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command not found: antlr4ng
I am trying to generate a parser using antlr4ng. I've already installed antlr4ng and antlr4ng-cli using npm install antlr4ng and npm install antlr4ng-cli. But when trying to execute antlr4ng -...