I have noticed that this produces an "Invalid Token" error:
{
:db/id #db/id[:db.part/user]
:db/ident :my.namespace/54
...
}
The problem is with using the number "54". It works fine if it is written:
{
:db/id #db/id[:db.part/user]
:db/ident :my.namespace/fifty-four
...
}
Why is this?
Such is the syntax of EDN (and Clojure in particular) for keywords:
[...] Keywords follow the rules of symbols, except they can (and must) begin with : [...]
in particular:
[...] Symbols begin with a non-numeric character and can contain alphanumeric characters and . * + ! - _ ? $ % & = < > [...]
Related
I have the following ANTLR (version 3) grammar:
grammar GRM;
options
{
language = C;
output = AST;
}
create_statement : CREATE_KEYWORD SPACE_KEYWORD FILE_KEYWORD SPACE_KEYWORD value -> ^(value);
value : NUMBER | STRING;
CREATE_KEYWORD : 'CREATE';
FILE_KEYWORD : 'FILE';
SPACE_KEYWORD : ' ';
NUMBER : DIGIT+;
STRING : (LETTER | DIGIT)+;
fragment DIGIT : '0'..'9';
fragment LETTER : 'a'..'z' | 'A'..'Z';
With this grammar, I am able to successfully parse strings like CREATE FILE dump or CREATE FILE output. However, when I try to parse a string like CREATE FILE file it doesn't work. ANTLR matches the text file (in the string) with lexer rule FILE_KEYWORD which is not the match that I was expecting. I was expecting it to match with lexer rule STRING.
How can I force ANTLR to do this?
Your problem is a variant on classic contextual keyword vs identifier issue, it seems.
Either "value" should be a lexer rule, not a parser rule, it's too late otherwise, or you should reorder the rules (or both).
Hence using VALUE = NUMBER | STRING (lexer rule) instead of lower case value (grammar rule) will help. The order of the lexer rules are also important, usually definition of ID ("VALUE" in your code) comes after keyword definitions.
See also : 'IDENTIFIER' rule also consumes keyword in ANTLR Lexer grammar
grammar GMR;
options
{
language = C;
output = AST;
}
create_statement : CREATE_KEYWORD SPACE_KEYWORD FILE_KEYWORD SPACE_KEYWORD value -> ^(value);
CREATE_KEYWORD : 'CREATE';
FILE_KEYWORD : 'FILE';
value : (LETTER | DIGIT) + | FILE_KEYWORD | CREATE_KEYWORD ;
SPACE_KEYWORD : ' ';
this works for me in ANTLRworks for input CREATE FILE file and for input CREATE FILE FILE if needed.
I have an unknown identifier on the local like some_values.cursor, I really don't understand why!
qry_update_set_fields (some_keys, some_values, some_unstored_field_names: LINKED_LIST[STRING]): STRING
require
same_some_keys_some_values_count: some_keys.count = some_values.count
local
l_val_c: like some_values.new_cursor
do
Result := ""
l_val_c := some_values.new_cursor
across
some_keys as l_key_c
loop
Result := l_key_c.item + "=" + l_val_c.item + ","
l_val_c.forth
end
if Result.ends_with (",") then
Result.remove_tail (1)
end
ensure
dont_modify_parameters: old some_keys.is_equal (some_keys) and old some_values.is_equal (some_values)
end
working
l_val_c: LINKED_LIST_CURSOR [STRING]
Neither working
l_val_c: LINKED_LIST_CURSOR [like some_values.item]
The example tries using an argument in the qualified anchored type like argument.some_feature. This is not supported. Types, anchored to arguments, are not part of the standard Eiffel and are supported only for backward compatibility in the form like argument.
I am having some difficulty in understanding how a String[] can be represented in a Guvnor rule. How can an array of strings be passed to a Java method that uses String[] as an argument from a rule in Guvnor?
I keep getting mismatched input errors, Error Code 102 when I attempt to validate the rule in Guvnor.
Any pointers/tips welcome
In the following rule, comm is a global object with a function sendMail with the function signature (String[] recipientlist, String alertType, String message)
rule "list-email"
dialect "java"
when
$result : Grade( subject == "Math" , $marks : mark >= 99.0 )
$emailList : "{xyz#abc.com, fgh#def.com}"
then
comm.sendMail($emailList, "High Grade Alert", "Scored: " + " Marks:" + Double.toString($marks));
It's not a good idea to try and introduce a String[] on the LHS - you aren't matching with it, and I doubt the syntax is correct. Use this - on the RHS it's Java:
rule "list-email"
dialect "java"
when
$result : Grade( subject == "Math" , $marks : mark >= 99.0 )
then
String[] addrs = new String[]{"xyz#abc.com", "fgh#def.com"};
comm.sendMail(addrs, "High Grade Alert", "Scored: " + " Marks:" + $marks );
end
I'm trying to use this javacc grammar https://java.net/downloads/javacc/contrib/grammars/C.jj to parse a C code containing bit fields
struct T{
int w:2;
};
struct T a;
The generated parser cannot parse this code:
$ javacc -DEBUG_PARSER=true C.jj && javac CParser.java && gcc -E input.c | java CParser
Java Compiler Compiler Version 5.0 (Parser Generator)
(type "javacc" with no arguments for help)
Reading from file C.jj . . .
File "TokenMgrError.java" is being rebuilt.
File "ParseException.java" is being rebuilt.
File "Token.java" is being rebuilt.
File "SimpleCharStream.java" is being rebuilt.
Parser generated successfully.
Note: CParser.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
C Parser Version 0.1Alpha: Reading from standard input . . .
Call: TranslationUnit
Call: ExternalDeclaration
Call: Declaration
Call: DeclarationSpecifiers
Call: TypeSpecifier
Call: StructOrUnionSpecifier
Call: StructOrUnion
Consumed token: <"struct" at line 5 column 1>
Return: StructOrUnion
Consumed token: <<IDENTIFIER>: "T" at line 5 column 8>
Consumed token: <"{" at line 5 column 9>
Call: StructDeclarationList
Call: StructDeclaration
Call: SpecifierQualifierList
Call: TypeSpecifier
Consumed token: <"int" at line 6 column 2>
Return: TypeSpecifier
Return: SpecifierQualifierList
Call: StructDeclaratorList
Call: StructDeclarator
Call: Declarator
Call: DirectDeclarator
Consumed token: <<IDENTIFIER>: "w" at line 6 column 6>
Return: DirectDeclarator
Return: Declarator
Return: StructDeclarator
Return: StructDeclaratorList
Return: StructDeclaration
Return: StructDeclarationList
Return: StructOrUnionSpecifier
Return: TypeSpecifier
Return: DeclarationSpecifiers
Return: Declaration
Return: ExternalDeclaration
Return: TranslationUnit
C Parser Version 0.1Alpha: Encountered errors during parse.
ParseException: Encountered " ":" ": "" at line 6, column 7.
Was expecting one of:
";" ...
"," ...
"(" ...
"[" ...
"[" ...
"(" ...
"(" ...
"," ...
";" ...
";" ...
";" ...
"[" ...
"(" ...
"(" ...
at CParser.generateParseException(CParser.java:4279)
at CParser.jj_consume_token(CParser.java:4154)
at CParser.StructDeclaration(CParser.java:433)
at CParser.StructDeclarationList(CParser.java:372)
at CParser.StructOrUnionSpecifier(CParser.java:328)
at CParser.TypeSpecifier(CParser.java:274)
at CParser.DeclarationSpecifiers(CParser.java:182)
at CParser.Declaration(CParser.java:129)
at CParser.ExternalDeclaration(CParser.java:96)
at CParser.TranslationUnit(CParser.java:77)
at CParser.main(CParser.java:63)
I tried to change (line 245)
(...) LOOKAHEAD( { isType(getToken(1).image) } )TypedefName() )
to
LOOKAHEAD( { isType(getToken(1).image) } ) TypedefName2()
(...)
void TypedefName2() : {}
{
TypedefName() (LOOKAHEAD(2) ":" <INTEGER_LITERAL> )?
}
but it doesn't work (same error) .
Is there a simple way to fix the javaCC grammar to handle Bit Fields ?
Try fixing this by modifying the StructDeclarator() rule on lines 310..313 as follows:
void StructDeclarator() : {}
{
( Declarator() [ ":" ConstantExpression() ] | ":" ConstantExpression() )
}
The idea is to remove the need of lookahead by letting the parser make a decision by checking if the struct declarator starts with a colon ":".
How does one search for specific punctuation in Solr, such as :)? I have tried URL encoding the text but I still get this message:
org.apache.solr.search.SyntaxError: Cannot parse ':': Encountered " ":" ": "" at line 1, column 0.
Was expecting one of:
<NOT> ...
"+" ...
"-" ...
<BAREOPER> ...
"(" ...
"*" ...
<QUOTED> ...
<TERM> ...
<PREFIXTERM> ...
<WILDTERM> ...
<REGEXPTERM> ...
"[" ...
"{" ...
<LPARAMS> ...
<NUMBER> ...
<TERM> ...
"*" ...
Additionally, I need to perform this search on a text field, not on a string field. How should I configure the analyser to save punctuation?
Note that searching google for the subject is impossible due to two prolific Solr contributors with the name "Smiley"!
What configurations you have for the text field?
You should take care the splitting is not happening on the puntuations e.g. if using StandardTokenizerFactory or word delimiter filter.
You can define a custom field with WhitespaceTokenizerFactory or KeywordTokenizerFactory and have further filters like lower case on it.
Also, There are some characters which Solr/Lucene uses for some operation e.g. + - ! ( ) { } [ ] ^ " ~ * ? :
You would need to escape the special characters with backslash. Check Escape Special Characters
instead of :) search for "\:\ )" , both chars :,) have special meaning in SOLR.
for all special operatos you need to escape by prefixing with '\' char .