For grammar:
grammar qwe;
query
: COLUMN OPERATOR value EOF
;
COLUMN
: [a-z_]+
;
OPERATOR
: ('='|'>'|'<')
;
SCALAR
: [a-z_]+
;
value
: SCALAR
;
WS : [ \t\r\n]+ -> skip ;
there are identical rules COLUMN
and SCALAR
. Here I was advised to use grun
aliases.
I installed it for my Ubuntu. And for folders structure:
ran this from project learning_antlr4
level:
grun qwe tokens -tokens < qwe/qwe.tokens
The output was empty.
What do I wrong? Where that aliases are saved?
Assuming you have the grun alias set up (if not, see the QuickStart at the tops of this page https://www.antlr.org):
What you want is to view the token stream produced by the Lexer processing your input (not your qwe.tokens
file)
qwe.txt:
total_sales>qwe
ANTLR on master [✘+?]
➜ antlr4 qwe.g4
ANTLR on master [✘+?]
➜ javac *.java
ANTLR on master [✘+?]
➜ grun qwe tokens -tokens < qwe.txt
[@0,0:10='total_sales',<COLUMN>,1:0]
[@1,11:11='>',<OPERATOR>,1:11]
[@2,12:14='qwe',<COLUMN>,1:12]
[@3,15:14='<EOF>',<EOF>,1:15]
AS you can see... both total_sales
and qwe
are recognized as COLUMN
tokens,