Problem with the new lines ?

[stefv]

Hi,

I have a strange problem. At first it was with my grammar but I adapted the grammar of the sample2 to use a new line based grammar:

{WS} = {Whitespace} - {CR} - {LF} Whitespace = {WS}+

NewLine = {CR}{LF}|{CR}

<nl> ::= NewLine <nl> !One or more | NewLine

<Statements> ::= <Statement> <nl> <Statements> | <Statement> <nl>

Finally, here the kind of code I used with this grammar: assign n = 1 while n >= 1 do display n assign n = n - 1 end display 'Blast off!'

This code is working perfectly with Gold Parser Builder 5.2 but if I try it with the Iden Java Engine, I have this error:

2013-06-25 23:20:23 ERROR HtmlController:255 - Lexical error at line 1, column 13. Read (Error) 2013-06-25 23:20:23 ERROR HtmlController:256 - assign n = 1 while n >= 1 do display n assign n = n - 1 end display 'Blast off!'

I just have "(Error)" without a real reason of the error.

Is there a mistake in my grammar or one problem with the Iden Java Engine ?

Thank you for your help.

Regards, Stef

[ridencww]

It is hard to tell if the problem is in the grammar or the engine without the complete grammar. Can you provide a link to the complete grammar or email it to me? riden -at- creativewidgetworks -dot- com

[stefv]

Thank you for your quick reply.

Like I said, I just reused the grammar from the sample2 adapted for a line based grammar:

"Name" = 'Simple' "Author" = 'Devin Cook' "Version" = '2.0' "About" = 'This is a very simple grammar designed for use in examples'

"Case Sensitive" = False "Start Symbol" = <Statements>

Comment Block @= { Nesting = All, Advance = Character }

Comment Start = '/' Comment End = '/'

Comment Line = '//'

{String Ch 1} = {Printable} - [''] {String Ch 2} = {Printable} - ["]

Id = {Letter}{AlphaNumeric}*

! String allows either single or double quotes

StringLiteral = '' {String Ch 1}* '' | '"' {String Ch 2}* '"'

NumberLiteral = {Digit}+('.'{Digit}+)?

{WS} = {Whitespace} - {CR} - {LF} Whitespace = {WS}+

NewLine = {CR}{LF}|{CR}

<nl> ::= NewLine <nl> !One or more | NewLine

<Statements> ::= <Statement> <nl> <Statements> | <Statement> <nl>

<Statement> ::= display <Expression> | display <Expression> read ID | assign ID '=' <Expression> | while <Expression> do <Statements> end | if <Expression> then <Statements> end | if <Expression> then <Statements> else <Statements> end

<Expression> ::= <Expression> '>' <Add Exp> | <Expression> '<' <Add Exp> | <Expression> '<=' <Add Exp> | <Expression> '>=' <Add Exp> | <Expression> '==' <Add Exp> | <Expression> '<>' <Add Exp> | <Add Exp>

<Add Exp> ::= <Add Exp> '+' <Mult Exp> | <Add Exp> '-' <Mult Exp> | <Add Exp> '&' <Mult Exp> | <Mult Exp>

<Mult Exp> ::= <Mult Exp> '*' <Negate Exp> | <Mult Exp> '/' <Negate Exp> | <Negate Exp>

<Negate Exp> ::= '-' <Value> | <Value>

<Value> ::= ID
| StringLiteral | NumberLiteral | '(' <Expression> ')'

[stefv]

I'm sorry Ralph, I think I made a mistake somewhere because reusing exacly the skeleton program, it's working. I will start again from the skeleton.

[stefv]

I found the origin of the problem. I was using a source code to parse from a XML file (in one element). When I'm reading this code to put it in a String, the newlines are \n. The engine can't accept it because it's not the definition in the grammar for a newline.

But if I change the \n to become \r\n, it's working because the grammar accept it.

Finally, it's not a problem from the engine but from the grammar. I reused the example for the newline from the Gold website: http://goldparser.org/doc/grammars/example-line-based.htm

But I think it's a mistake and it must be: NewLine = {CR}{LF}|{CR}|{LF}

[ridencww]

Thank you for following up and I'm glad you're moving forward. I will close this issue, but don't hesitate to open a new one if you find or suspect defects in the engine. I ported Devin's reference engine as closely as possible, but I have run into a few defects that weren't caught by my tests.

I'd be interested in ways that the engine can provide more useful error messages. As a developer, I don't like cryptic or incomplete error messages. Any input or examples of unhelpful error messages are welcome.