[il-antlr-interest: 31311] [antlr-interest] tree grammar and list via +=
Hello again,
since you helped me nicely last time a have an other question:
Is it now possible to use a list in a tree grammar? I found a mail from
2007 saying it will be implemented soon.
But when I try it, I get a very long error Message.
Here is the grammar:
tree grammar TreeWalker;
options{
language=C;
tokenVocab=Grammar;
output=AST;
ASTLabelType=pANTLR3_BASE_TREE;
}
...
idrefs : list+=id+ ;
...
When generating the code, I get this:
error(10): internal error: /TreeWalker.g :
java.util.NoSuchElementException: template listLabelAST has no such
attribute: elem in template context [outputFile treeParser
genericParser(...) rule ruleBlockSingleAlt alt element
positiveClosureBlock altSwitchCase alt element ruleRefAndListLabel invoke
listLabelAST arg context]
...
Sounds to me like I cannot use a list with output AST, but when I set
output to template I get:
error(10): internal error: no such group file ST.stg
output=AST would be neccessary anyway.
Any suggestions? Thanks in advance
Bastian
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[il-antlr-interest: 31313] Re: [antlr-interest] Memory management of C target
Dear Jim On 01.02.2011 18:15, Jim Idle wrote: snip I think that in 3.3 I have fixed a bug that was not releasing memory references when building a tree until the tree was freed. Try making a version that does not build a tree and see how it differs. snip Ok, made a version of my grammar that doesn't build a tree: libantlr3c-3.2, no tree output: works, uses about 600mb memory libantlr3c-3.2, tree output: crash, wants more than 2gb libantlr3c-3.3-SNAPSHOT, no tree output: works, uses about 630mb memory libantlr3c-3.3-SNAPSHOT, tree output: crash, wants more than 2gb The only changes to the grammar where removing/adding output = AST;. Is your fix already in the current SNAPSHOT? Thanks Marco List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31314] Re: [antlr-interest] Memory management of C target
I think that the fix is in there, which means that your input is too big to build the tree in the way it is being done. Write an input stream wrapper that splits the input by just returning EOF at the split point then resets to the next unit. How are you ending up with 640,000 lines of C input? Jim -Original Message- From: antlr-interest-boun...@antlr.org [mailto:antlr-interest- boun...@antlr.org] On Behalf Of Marco Trudel Sent: Wednesday, February 02, 2011 8:20 AM To: antlr-interest@antlr.org Subject: Re: [antlr-interest] Memory management of C target Dear Jim On 01.02.2011 18:15, Jim Idle wrote: snip I think that in 3.3 I have fixed a bug that was not releasing memory references when building a tree until the tree was freed. Try making a version that does not build a tree and see how it differs. snip Ok, made a version of my grammar that doesn't build a tree: libantlr3c-3.2, no tree output: works, uses about 600mb memory libantlr3c-3.2, tree output: crash, wants more than 2gb libantlr3c-3.3-SNAPSHOT, no tree output: works, uses about 630mb memory libantlr3c-3.3-SNAPSHOT, tree output: crash, wants more than 2gb The only changes to the grammar where removing/adding output = AST;. Is your fix already in the current SNAPSHOT? Thanks Marco List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your- email-address List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31315] [antlr-interest] SLL(2) in The Definitive ANTLR Reference
I was reading about the following grammar on page 287 of the PDF document grammar t; s : X r A B | Y r B ; r : A | ; I don't see where the problem is since the alternatives in s begin with two different tokens X and Y. I think that since these two tokens are different I can easily construct a DFA that would unambiguously parse a stream of tokens. I sense that this example was supposed to bring out a finer point about how ANTLR generates parsers but I'm afraid that it is being lost on me. Regards, Alan List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31316] Re: [antlr-interest] Memory management of C target
On 02.02.2011 18:01, Jim Idle wrote: I think that the fix is in there, which means that your input is too big to build the tree in the way it is being done. Write an input stream wrapper that splits the input by just returning EOF at the split point then resets to the next unit. Actually I already rewrote my splitter. Now I get almost exactly the same performance for parsing the files splitted and as a whole. Also the overall memory consumption is much better this way since I actually build an AST in another framework. I only use antlr to parse the input. I just wanted to compare the performance of different approaches. I now also tried to use the start and end pointers to the input instead of using $text. Doesn't make a difference in memory consumption or speed. So I stick with the convenient $text. How are you ending up with 640,000 lines of C input? I'm doing some program analysis and preprocess the C programms with CIL [1]. vim and libgsl for instance then are about half a million lines of code. Thanks for your time Marco [1] http://hal.cs.berkeley.edu/cil/ Jim -Original Message- From: antlr-interest-boun...@antlr.org [mailto:antlr-interest- boun...@antlr.org] On Behalf Of Marco Trudel Sent: Wednesday, February 02, 2011 8:20 AM To: antlr-interest@antlr.org Subject: Re: [antlr-interest] Memory management of C target Dear Jim On 01.02.2011 18:15, Jim Idle wrote: snip I think that in 3.3 I have fixed a bug that was not releasing memory references when building a tree until the tree was freed. Try making a version that does not build a tree and see how it differs. snip Ok, made a version of my grammar that doesn't build a tree: libantlr3c-3.2, no tree output: works, uses about 600mb memory libantlr3c-3.2, tree output: crash, wants more than 2gb libantlr3c-3.3-SNAPSHOT, no tree output: works, uses about 630mb memory libantlr3c-3.3-SNAPSHOT, tree output: crash, wants more than 2gb The only changes to the grammar where removing/adding output = AST;. Is your fix already in the current SNAPSHOT? Thanks Marco List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your- email-address List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31317] [antlr-interest] JOB: Senior Software Engineer with Parsing Expertise needed at CISCO
Please contact Brent at brero...@cisco.com if you are interested in the job opening listed below. Regards, Brent Senior Software Engineer Location San Jose, California Security Technology Business Unit (STBU) within WSRTG, is seeking a Software Engineer. STBU offers network and content security solutions that enable our customers to collaborate with confidence. These solutions include our firewall, intrusion prevention, remote access/VPN, unified client, web and email security. Responsibilities: Develop software for the Cisco Adaptive Security Appliance (ASA) and more specifically for the SSL VPN Remote Access component. Program in C, C++ and Javascript on a Linux-based platform with a slew of open source and proprietary libraries and infrastructure. Small team is central owner of WebVPN functionality; engage in all aspects of the product life-cycle from specification, design to development and post release maintenance. Great opportunity to employ a breadth of software engineering skills in a highly visible product. The successful candidate would have 3+ years of industry experience or more, would have experience working on large projects, analyzing and debugging Layer 7 protocols, writing parsers for high level languages and has written javascript to generate javascript. This candidate will show talent, passion and pride in software architecture, authorship and quality, excellent collaboration skills, teamwork and cross functional aptitude. Expertise in most of the following areas is required: * Flash decompilation * Unix/POSIX/Linux application level programming * Very strong Javascript development skills, with ability to use debuggers and profilers * Ability to diagnose issues with proprietary protocols * knowledge of parsers, regular expressions * Strong knowledge of the HTTP protocol and HTML * NTLM, SSL, character encoding * Differences between browsers, proxies * Experience with tools and frameworks like wireshark, Pcap, HTTPwatch, Spidermonkey, webkit List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31318] Re: [antlr-interest] SLL(2) in The Definitive ANTLR Reference
try for rule 'r' though ;) Ter On Feb 2, 2011, at 9:07 AM, Alan D. Cabrera wrote: I was reading about the following grammar on page 287 of the PDF document grammar t; s : X r A B | Y r B ; r : A | ; I don't see where the problem is since the alternatives in s begin with two different tokens X and Y. I think that since these two tokens are different I can easily construct a DFA that would unambiguously parse a stream of tokens. I sense that this example was supposed to bring out a finer point about how ANTLR generates parsers but I'm afraid that it is being lost on me. Regards, Alan List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31319] [antlr-interest] Question of Repetead tokens and early termination
Hi there. I am having trouble with the error handling.
I have a grammar for recoignize linear expression. And it works great!.
The grammar for a linear expresion is the following:
tokens
{
PLUS= '+';
MINUS = '-';
MUL = '*';
DIV = '/';
}
linexpr : (MINUS|PLUS)? linterm ((PLUS|MINUS) linterm)*;
linterm : factor? ID;
expr returns [double value]
: e=term {$value = $e.value;}
( PLUS e=term {$value += $e.value;}
| MINUS e=term {$value -= $e.value;}
)*;
term returns [double value]
: f=factor {$value = $f.value;}
( MUL f=factor {$value *= $f.value;}
| DIV f=factor {$value /= $f.value;}
)*;
factor returns [double value]
: DOUBLE {$value = Double.parseDouble($DOUBLE.text);}
| '(' e=expr ')'{$value = $e.value;};
ID : ('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')*;
DOUBLE
: ('0'..'9')+
| ('0'..'9')+ '.' ('0'..'9')* EXPONENT?
| '.' ('0'..'9')+ EXPONENT?
| ('0'..'9')+ EXPONENT
;
fragment EXPONENT : ('e'|'E') ('+'|'-')? ('0'..'9')+ ;
NEWLINE:'\r'? '\n' { $channel = HIDDEN; };
WS : (' '|'\t'|'\n'|'\r')+ { $channel = HIDDEN; };
But the problem ocurrs when, for example, i have:
x x x
Then the parsers stop after processing the first x.
¿How do i correctly emit an invalid syntax error?.
I Try with the catch EarlyExitException, but it doesn't works.
I Want, inside my java aplicacition to catch this, and show to the final
user.
Something like this...
//line is equals to the user input...
CharStream cs = new ANTLRStringStream(line);
LinearExpressionLexer lexer = new LinearExpressionLexer(cs);
CommonTokenStream tokens = new CommonTokenStream(lexer);
LinearExpressionParser parser = new
LinearExpressionParser(tokens);
res = parser.linexpr (); // and here, it's suppose to fail,
but it isn't.
Actually, the linexpr does returns some kind of data whose type is a
custom class called LinearExpresion. I omit to put the return in the
linearexpr parser rule to simplify things.
Hope anyone can help me.
Greettings and thanks for advance.
Víctor.
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[il-antlr-interest: 31321] Re: [antlr-interest] Question of Repetead tokens and early termination
Your grammar does not mention the EOF token. (more below...)
On Wed, 2011-02-02 at 16:18 -0300, Victor Giordano wrote:
Hi there. I am having trouble with the error handling.
I have a grammar for recoignize linear expression. And it works great!.
The grammar for a linear expresion is the following:
tokens
{
PLUS= '+';
MINUS = '-';
MUL = '*';
DIV = '/';
}
linexpr : (MINUS|PLUS)? linterm ((PLUS|MINUS) linterm)*;
linterm : factor? ID;
expr returns [double value]
: e=term {$value = $e.value;}
( PLUS e=term {$value += $e.value;}
| MINUS e=term {$value -= $e.value;}
)*;
term returns [double value]
: f=factor {$value = $f.value;}
( MUL f=factor {$value *= $f.value;}
| DIV f=factor {$value /= $f.value;}
)*;
factor returns [double value]
: DOUBLE {$value = Double.parseDouble($DOUBLE.text);}
| '(' e=expr ')'{$value = $e.value;};
ID : ('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')*;
DOUBLE
: ('0'..'9')+
| ('0'..'9')+ '.' ('0'..'9')* EXPONENT?
| '.' ('0'..'9')+ EXPONENT?
| ('0'..'9')+ EXPONENT
;
fragment EXPONENT : ('e'|'E') ('+'|'-')? ('0'..'9')+ ;
NEWLINE:'\r'? '\n' { $channel = HIDDEN; };
WS : (' '|'\t'|'\n'|'\r')+ { $channel = HIDDEN; };
But the problem ocurrs when, for example, i have:
x x x
Then the parsers stop after processing the first x.
¿How do i correctly emit an invalid syntax error?.
I Try with the catch EarlyExitException, but it doesn't works.
I Want, inside my java aplicacition to catch this, and show to the final
user.
Something like this...
//line is equals to the user input...
CharStream cs = new ANTLRStringStream(line);
LinearExpressionLexer lexer = new LinearExpressionLexer(cs);
CommonTokenStream tokens = new CommonTokenStream(lexer);
LinearExpressionParser parser = new
LinearExpressionParser(tokens);
res = parser.linexpr (); // and here, it's suppose to fail,
but it isn't.
Actually, the linexpr does returns some kind of data whose type is a
custom class called LinearExpresion. I omit to put the return in the
linearexpr parser rule to simplify things.
Hope anyone can help me.
Greettings and thanks for advance.
Greetings!
By design ANTLR parsers stop after consuming the longest possible VALID
input sequence. I believe the rational for this is that any remaining
input will be available for some other tool to process.
If you want ANTLR to try to process the entire input, reporting and
recovering from syntax errors in the input; you must tell it to do that.
By referring to the EOF token (a special built-in token) in your
top-most rule will cause ANTLR to consume the entire input string. E.g.
the parse will not have a valid input until the EOF is seen and so will
consume all of the input sentence.
I suggest adding a top-level rule similar to:
start : linexpr EOF! ;
and then call parser.start() instead of parser.linexpr() in your driver.
(note the ! meta-character after the EOF token above will keep the EOF
out of any AST produced, but you do not seem to be building an AST so it
won't make any difference...)
Hope this helps...
-jbb
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[il-antlr-interest: 31322] Re: [antlr-interest] SLL(2) in The Definitive ANTLR Reference
Ahh, the DFA for the 'r' rule. That makes sense now. Interesting example. Thanks Terence and Sam! Regards, Alan On Feb 2, 2011, at 11:17 AM, Terence Parr wrote: try for rule 'r' though ;) Ter On Feb 2, 2011, at 9:07 AM, Alan D. Cabrera wrote: I was reading about the following grammar on page 287 of the PDF document grammar t; s : X r A B | Y r B ; r : A | ; I don't see where the problem is since the alternatives in s begin with two different tokens X and Y. I think that since these two tokens are different I can easily construct a DFA that would unambiguously parse a stream of tokens. I sense that this example was supposed to bring out a finer point about how ANTLR generates parsers but I'm afraid that it is being lost on me. Regards, Alan List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31326] Re: [antlr-interest] tree pattern matching rewrite bug ?
Just a little more on the issue below, when I swapped the tree grammars that were provoking the Can't set single child to a list error from pattern matching mode (filter = true) to complete grammars (filter = false) the tree rewrites run successfully. I'd still be interested to hear if issue ANTLR-419 is known to be current problem. cheers Michael On 2 February 2011 11:42, Michael Bedward michael.bedw...@gmail.com wrote: Hello all, I hope it's ok to ask about ANTLR Jira issues on this list. I've been using pattern matching for some simple tree rewriting tasks. Most work, but for some of them I keep hitting the error Can't set single child to a list. I've spent quite a bit of time in the debugger without success. Google found this issue for version 3.2 which appears to be related and still open (which I assume means not fixed in version 3.3)... http://www.antlr.org/jira/browse/ANTLR-419 Before I spend more time debugging, I wonder if anyone can tell me if this is indeed a current bug. If so I can probably work around it by going back to rewriting using a complete grammar. cheers Michael List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
[il-antlr-interest: 31328] [antlr-interest] Catching errors
Okey. So adding and EOF forces the parser to go to the end of the input
in search of others tokens in correct order.
1)But a still have a problem, consider the following grammar:
grammar LinearMath;
tokens
{
PLUS = '+';
MINUS = '-';
MUL= '*';
DIV= '/';
}
inecuation: linexpr ((RELATIONSHIP) linexpr)+ EOF!;
catch [UnwantedTokenException ute]
{
System.out.println (inecuation UnwantedTokenException +
ute.toString());
throw ute;
}
linexpr : (MINUS|PLUS)? linterm ((PLUS|MINUS) linterm)* EOF;
linterm : factor? ID;
expr returns [double value]
: e=term {$value = $e.value;}
(PLUS e=term {$value += $e.value;}
|MINUS e=term {$value -= $e.value;}
)*;
term returns [double value]
: f=factor {$value = $f.value;}
(MUL f=factor {$value *= $f.value;}
|DIV f=factor {$value /= $f.value;}
)*;
factor returns [double value]
: DOUBLE {$value = Double.parseDouble($DOUBLE.text);}
| '(' e=expr ')'{$value = $e.value;};
ID :('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')*;
DOUBLE
: ('0'..'9')+
|('0'..'9')+ '.' ('0'..'9')* EXPONENT?
| '.' ('0'..'9')+ EXPONENT?
| ('0'..'9')+ EXPONENT
;
fragment EXPONENT : ('e'|'E') ('+'|'-')? ('0'..'9')+ ;
NEWLINE:'\r'? '\n' { $channel = HIDDEN; };
WS : (' '|'\t'|'\n'|'\r')+ { $channel = HIDDEN; };
RELATIONSHIP : ''|'='|'='|''|'=';
and with the following input: x y x
that isn't a valid inecuation beacause the y x must have a binary
aritmetic operator (PLUS OR MINUS). The parser do his job very well, he
consume the x then later y and when it reachs the seconds x it
emits an UnwantedTokenException. The think is, that i am not being
able to catch it, and display an error to the final user. Look that i am
using to parse that input the inecuation rule.
Hope anyone can help me with this again.
2) Other thing is about invalid tokens, i manage to treat then
overriding a member function of the lexer called nextToken(), like this:
@lexer::members
{
@Override
public Token nextToken()
{
while (true) {
state.token = null;
state.channel = Token.DEFAULT_CHANNEL;
state.tokenStartCharIndex = input.index();
state.tokenStartCharPositionInLine =
input.getCharPositionInLine();
state.tokenStartLine = input.getLine();
state.text = null;
if ( input.LA(1)==CharStream.EOF ) {
return Token.EOF_TOKEN;
}
try {
mTokens();
if ( state.token==null ) {
emit();
}
else if ( state.token==Token.SKIP_TOKEN ) {
continue;
}
return state.token;
}
catch (RecognitionException re) {
reportError(re);
throw new RuntimeException(Invalid Character
: + (char) (re.c));
// or throw Error
}
}
}
}
¿It's that the correct way?
Well that is all!!!
Thanks for advance!.
Victor!!
El 02/02/2011 05:32 p.m., John B. Brodie escribió:
Your grammar does not mention the EOF token. (more below...)
On Wed, 2011-02-02 at 16:18 -0300, Victor Giordano wrote:
Hi there. I am having trouble with the error handling.
I have a grammar for recoignize linear expression. And it works great!.
The grammar for a linear expresion is the following:
tokens
{
PLUS= '+';
MINUS = '-';
MUL = '*';
DIV = '/';
}
linexpr : (MINUS|PLUS)? linterm ((PLUS|MINUS) linterm)*;
linterm : factor? ID;
expr returns [double value]
: e=term {$value = $e.value;}
( PLUS e=term {$value += $e.value;}
| MINUS e=term {$value -= $e.value;}
)*;
term returns [double value]
: f=factor {$value = $f.value;}
( MUL f=factor {$value *= $f.value;}
| DIV f=factor {$value /= $f.value;}
)*;
factor returns [double value]
: DOUBLE {$value = Double.parseDouble($DOUBLE.text);}
| '(' e=expr ')'{$value = $e.value;};
ID :('a'..'z'|'A'..'Z'|'_') ('a'..'z'|'A'..'Z'|'0'..'9'|'_')*;
DOUBLE
: ('0'..'9')+
| ('0'..'9')+ '.' ('0'..'9')* EXPONENT?
| '.' ('0'..'9')+ EXPONENT?
| ('0'..'9')+ EXPONENT
;
fragment EXPONENT : ('e'|'E') ('+'|'-')? ('0'..'9')+ ;
NEWLINE:'\r'? '\n' { $channel = HIDDEN; };
WS : (' '|'\t'|'\n'|'\r')+ { $channel = HIDDEN; };
But the problem ocurrs when, for example,
[il-antlr-interest: 31330] Re: [antlr-interest] Which approach for an Interpreter: Tree Grammar vs AST-Visitor
So would it be better to have an example like the Pie language use a tree grammar or is the hand-written visitor code a better approach? What are the pros and cons? Any help appreciated. A pure interpreter would read statements one by one and execute them directly. A compiler would read the whole source in one chunk and translate it before execution. You can take any approach inbetween as well. That said, I believe parsing the whole file and translating into an AST is not really interpretation. But there is still the approach to parse statement for statement, and here I would definitely separate the grammar from execution code through an AST. file: statement+ EOF; statement: . My interpreter would open the file, construct parser and lexers, manage variables and scope, repeatedly ask the parser to return the AST for the next statement and send it for execution. This way you would get the typical behaviour that syntax errors or else are detected during execution time. And if you were to change your mind towards a compiler, the grammar and AST construction would not change as you simply call the file method on the parser. Of course it is more intersting if your interpreted language allows methods/procedures/functions as then parsing the source file would not be linear. Hiran ___ Neu: WEB.DE De-Mail - Einfach wie E-Mail, sicher wie ein Brief! Jetzt De-Mail-Adresse reservieren: https://produkte.web.de/go/demail02 List: http://www.antlr.org/mailman/listinfo/antlr-interest Unsubscribe: http://www.antlr.org/mailman/options/antlr-interest/your-email-address -- You received this message because you are subscribed to the Google Groups il-antlr-interest group. To post to this group, send email to il-antlr-inter...@googlegroups.com. To unsubscribe from this group, send email to il-antlr-interest+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/il-antlr-interest?hl=en.
