I'm trying to build Abstract Syntax Tree for Java in Python with antlr4 package.
I've downloaded Java grammar from
https://github.com/antlr/grammars-v4/blob/master/java8/Java8.g4
I want to use that grammar file to produce JavaLexer and JavaParser for Python2.
When I say
"$ antlr4 -Dlanguage=Python2 Java8.g4"
an error occured.That error is
error(134): Java8.g4:73:0: symbol type conflicts with generated code in target language or runtime
NOTE: I've deleted parts with Character.isJavaIdentifierPart(). Because these lines is not proper for python and i will use just ASCII.
Python has built-in function called type. Antlr4 prints an error for line 73 of the grammar:
type
: primitiveType
| referenceType
;
Looks like there is a name conflict and you have to rename type to something else in your grammar.
Related
I am getting below error inspite of correct python code don't know how to resolve this error. Any help is much appreciated
org.apache.nifi.processor.exception.ProcessException: javax.script.ScriptException: SyntaxError: no viable alternative at input '*' in <script> at line number 35 at column number 26
python code
def get_match_list(regEx, line):
match = re.search(regEx, line)
print(match)
if match:
match_list = [*match.groups()] # this is the line exception is pointed
return match_list
else:
return []
It looks like jython use python 2.7 and as Unpacking Generalizations is a feature that introduced in python 3.5 you can not use this syntax in jython, so an alternative way to convert a tuple to a list is that use list ( match.groups) it works fine in older versions of python and current version of jython (2.7.2)
I have a separated parser and lexer grammar and want to run org.antlr.v4.gui.TestRig to debug/test my grammar.
My lexer grammar start with:
lexer grammar TestLexer;
IDS: [a-zA-Z];
WS: [ \t];
NL: [\r?\n];
...
and my parser grammar start with:
parser grammar TestParser;
options { tokenVocab=TestLexer; }
testRule: WS* IDS+ NL;
...
My classpath env variable points to complete antlr.jar and current directory.
antlr is an alias to java org.antlr.v4.Tool
grun is an alias to java org.antlr.v4.gui.TestRig.
When I run antlr TestParser.g4 && javac *.java the parser code gets generated and compiled.
When I run grun TestParser testRule -gui I get the error:
Exception in thread "main" java.lang.ClassCastException: class TestParser
at java.lang.Class.asSubclass(Class.java:3404)
at org.antlr.v4.gui.TestRig.process(TestRig.java:135)
at org.antlr.v4.gui.TestRig.main(TestRig.java:119)
And when I run grun Test testRule -gui I get the error:
Can't load Test as lexer or parser
I don't have any problems when using a combined grammar.
What's missing in order to run TestRig?
When using separated lexer and parser you have to generate the code for the lexer and parser. This is not done automatically by generating the code for the parser alone.
Execute:
antlr TestLexer.g4
antlr TestParser.g4
javac *.java
After generating the code for both (lexer and parser) you have to run:
grun Test -gui testInput.txt
where testInput.txt contains some test input to parse.
Note: When using separated lexer and parser it's expected that the lexer ends on Lexer and the parser ends on Parser. The common part of the files is the name of grammar.
I.e TestLexer and TestParser -> Test is the name of the grammar.
After some research I haven't found a solution, but quite alot of people with this problem:
I am trying to do a XQuery Transformation in a Java Application using
net.sf.saxon.s9api
However I get this error when trying to compile XQueryExecutable exec = compiler.compile(...)); my XQuery:
Error on line 13 column 3 of AivPumaRequest.xquery:
XPST0081 XQuery static error near #... fn-bea:inlinedXML(fn:concat#:
Prefix fn-bea has not been declared
Error on line 44 column 102 of AivPumaRequest.xquery:
XPST0081 XQuery static error near #... div xdt:dayTimeDuration('P1D'#:
Prefix xdt has not been declared
Error on line 199 column 3 of AivPumaRequest.xquery:
XPST0081 XQuery static error near #... fn-bea:inlinedXML(fn:concat#:
Prefix fn-bea has not been declared
Error on line 282 column 4 of AivPumaRequest.xquery:
XPST0081 XQuery static error near #... {fn-bea:inlinedXML(fn:concat#:
Prefix fn-bea has not been declared
net.sf.saxon.s9api.SaxonApiException: Prefix fn-bea has not been declared
Is there a way to static include this prefix or what am I missing so my XQuery Engine (SAXON) finds the Prefix?
The simple answer to your question is that you can declare namespace prefixes either within the query prolog using
declare namespace fn-bea = "http://some-appropriate-uri";
or in the Saxon API using
XQueryCompiler.declareNamespace("fn-bea", "http://some-appropriate-uri")
But this won't get you any further unless (a) you know what URI to bind the prefixes to, and (b) you make the functions with these names available to the query processor.
The reference to xdt:dayTimeDuration suggests to me that this query was written when XQuery was still a working draft. If you look at the 2005 working draft, for example
https://www.w3.org/TR/2005/CR-xquery-20051103/
you'll see in section 2 that it uses a built-in prefix
xdt = http://www.w3.org/2005/xpath-datatypes
By the time XQuery 1.0 became a recommendation, the dayTimeDuration data type had been moved into the standard XML Schema (xs) namespace, so you can probably simply replace "xdt" by "xs" - though you should be aware that the semantics of the language probably changed in minor details as well.
As for fn-bea:inlinedXML, the choice of prefix suggests to me that this was probably a built-in vendor extension in the BEA query processor, which was taken over by Oracle. The spec here:
https://docs.oracle.com/cd/E13162_01/odsi/docs10gr3/xquery/extensions.html
says:
fn-bea:inlinedXML Parses textual XML and returns an instance of the
XQuery 1.0 Data Model.
Which suggests that the function does something very similar to the XQuery 3.0 function fn:parse-xml(), and I suggest you try making that replacement in your query.
im new with ANTLR and I don´t know how to compile my grammar.
I´m using the v4.4 of ANTLR with a .g4 file that contains:
grammar JayGrammar;
program: KEYWORD_VOI KEYWORD_MAI SEPARATOR_PAB SEPARATOR_PCD (declarations statements);
declarations: (declaration)*;
declaration: (type identifiers);
type: (KEYWORD_INT | KEYWORD_BOO);
identifiers: (IDENTIFIER)*;
statements: (statement)*;
statement: (block | assignment | ifstatement | whilestatementk);
block: SEPARATOR_LAB statements SEPARATOR_LCD;
assignment: (IDENTIFIER OPERATOR_IGU expression);
ifstatement: KEYWORD_IF SEPARATOR_PAB expression SEPARATOR_PCD statement (KEYWORD_ELS statement)?;
whilestatementk: KEYWORD_WHI SEPARATOR_PAB expression SEPARATOR_PCD statement;
expression: conjunction ((OPERATOR_O) conjunction)*;
conjunction: relation ((OPERATOR_Y) relation)*;
relation: addition ((OPERATOR_REL) addition)*;
addition: term ((OPERATOR_SUM|OPERATOR_RES) term)*;
term: negation ((OPERATOR_POR|OPERATOR_DIV) negation)*;
negation:(OPERATOR_NO) factor;
factor: IDENTIFIER|LITERAL|SEPARATOR_PAB expression SEPARATOR_PCD;
INPUTELEMENT: (WHITESPACE|TOKEN);
WHITESPACE: (' '|'\t'|'\r'|'\n'|'\f');
TOKEN: (IDENTIFIER|KEYWORD_BOO|KEYWORD_ELS|KEYWORD_IF|KEYWORD_MAI|KEYWORD_VOI|KEYWORD_WHI|LITERAL
|SEPARATOR_COM|SEPARATOR_LAB|SEPARATOR_LCD|SEPARATOR_PAB|SEPARATOR_PCD|SEPARATOR_PYC
|OPERATOR_REL|OPERATOR_DIV|OPERATOR_IGU|OPERATOR_NO|OPERATOR_O|OPERATOR_POR|OPERATOR_RES|OPERATOR_SUM|OPERATOR_Y);
LITERAL: (BOOLEAN INTEGER);
KEYWORD_BOO: BOOLEAN;
KEYWORD_ELS:'else';
KEYWORD_IF: 'if';
KEYWORD_INT: 'int';
KEYWORD_MAI: 'main';
KEYWORD_VOI: 'void';
KEYWORD_WHI: 'while';
BOOLEAN: ('true'|'false');
INTEGER: (DIGIT+);
IDENTIFIER: (LETTER (LETTER| DIGIT)*);
DIGIT: ('0'..'9')+;
LETTER: ('a'..'z'|'A'..'Z')+;
SEPARATOR_PAB: '(';
SEPARATOR_PCD: ')';
SEPARATOR_LAB: '{';
SEPARATOR_LCD: '}';
SEPARATOR_PYC: ';';
SEPARATOR_COM: ',';
OPERATOR_IGU: ('=');
OPERATOR_SUM: ('+');
OPERATOR_RES: ('-');
OPERATOR_POR: ('*');
OPERATOR_DIV: ('/');
OPERATOR_REL: ('<'|'<='|'>'|'>='|'=='|'!=');
OPERATOR_Y: ('&&');
OPERATOR_O: ('||');
OPERATOR_NO: ('!');
I'll be really glad if someone can tell me how to create the lexer and the parser with the extension ".java" and then compile them to create the classes.
I´ve been using NetBeans but i´m really confused, If there is another IDE I can use or anything else, please help me.
This is explained in the Antlr4 "Getting Started" page.
Doing it by hand is as simple as this:
$ antlr4 YourGrammar.g4
$ javac YourGrammar*.java
... assuming that you have installed and configured a Java JDK and Antlr.
There are a number of ways to use Antrlr with the Netbeans IDE:
Just write / generate an Ant build script, and then modify it to include rules for running antlr4 etcetera. With allows you to incorporate Antlr into your builds without any IDE-specific integration.
Follow the instructions here on integrating Antlr into Netbeans,
Install and use the Antlrworks 2 plugin.
I am working on a DSL wherein I am supposed to call Java Functions I have written. How can they be called in XText Grammar definition rules ?
Example
Sample.xtext
Data:
'Data'':'
(objectRules += ObjectRule)+ //Call to Java Function here
;
I am writng the grammar and I want to invoke Java Function to perform further processing like pasting a block of code when the Rule is encountered.
Please refer to the documentation on Xbase if you want to use Java from your Xtext languages.
The pattern would be something like this:
grammar org.acme.MyDsl with org.eclipse.xtext.xbase.Xbase
generate ..
MyConcept:
operation=ID '(' ')' body = XBlockExpression
;
This would allow things like
myOperation() {
System.out.println("")
}