Assume
owner=owner
name=name
I expect StringTemplate
<pre>$owner$ touch \\$name$</pre><br>
to generate
<pre>owner touch \name</pre><br>
But it's giving out an error
Can't parse chunk: </pre><br>
line 1:1: unexpected char: '<'
at org.antlr.stringtemplate.language.ActionLexer.nextToken(ActionLexer.java:220)
at antlr.TokenBuffer.fill(TokenBuffer.java:69)
at antlr.TokenBuffer.LA(TokenBuffer.java:80)
at antlr.LLkParser.LA(LLkParser.java:52)
at org.antlr.stringtemplate.language.ActionParser.action(ActionParser.java:111)
at org.antlr.stringtemplate.StringTemplate.parseAction(StringTemplate.java:876)
at org.antlr.stringtemplate.language.TemplateParser.action(TemplateParser.java:162)
at org.antlr.stringtemplate.language.TemplateParser.template(TemplateParser.java:127)
at org.antlr.stringtemplate.StringTemplate.breakTemplateIntoChunks(StringTemplate.java:850)
at org.antlr.stringtemplate.StringTemplate.setTemplate(StringTemplate.java:441)
at org.antlr.stringtemplate.StringTemplate.<init>(StringTemplate.java:308)
at org.antlr.stringtemplate.StringTemplate.<init>(StringTemplate.java:293)
If I add a space between \\ and $, it works as expected.
<pre>$owner touch \\ $name</pre><br>
will generate
<pre>owner touch \ name</pre><br>
It appears that it interprets \\$ as escaping \$ instead of \\
StringTemplate java 3.2.1
Any idea how to write the correct StringTemplate? Is this a bug?
Related
I'm creating a parser in Antlr4 and Python. Below is the Lexer rules I created in Antlr.
VARIABLE_ID : [$][a-zA-Z][a-zA-Z0-9_]*;
ARRAY_ID : [*][a-zA-Z][a-zA-Z0-9_]*;
STRINGCONST : ["][/|:.a-zA-Z0-9 ]+["];
WS : [ \r\t\f\n]+ -> skip;
I am looking at the STRINGCONST rule and I'm trying to add symbols such as - and ~, however, since they are escapement characters, Antlr is just throwing errors for me. I've tried escaping them with themselves and I haven't been able to get that to work.
Is there a way to include them in the STRINGCONST rule? The basic idea is that I want a string to be identified as any character between two " " marks however I'm happy to limit it to what's currently in the rule as long as I can get - and ~ in there as well.
You can escape chars by adding a \ in front of them:
STRINGCONST : ["] [/|:.a-zA-Z0-9 \-~]+ ["];
And note that ~ has no special meaning inside a char class (only outside of them), so ~ doesn't need to be escaped.
I noticed while experimenting with tr///, that it doesn't seem to translate backslashes, even when escaped. For example,
say TR"\^/v"." given 'v^/\\';
say TR"\\^/v"." given 'v^/\\';
say TR"\ ^/v"." given 'v^/\\';
All of them output ...\ rather than what I expected, ....
There's some other weird behaviour too, like \ seemingly only escaping lowercase letters, but the docs page doesn't have much information... What exactly is the behaviour of backslashes (\) in transliteration (tr///)?
There is a bug caused by backslashes getting swallowed instead of correctly escaping things in the grammar for tr///.
say TR/\\// given '\\'
===SORRY!=== Error while compiling:
Malformed replacement part; couldn't find final /
at line 2
------> <BOL>⏏<EOL>
I have raised https://github.com/rakudo/rakudo/issues/2456 and submitted https://github.com/rakudo/rakudo/pull/2457 which fixes it.
The second part of the answer is that Perl 6 tries quite hard in some quoting constructs to only interpret \ as an escape for valid escape sequences, i.e. \n, \r, \s, \', etc. Otherwise it is left as a literal \.
I do not have an explanation for the observed problem. However, when you use the Perl 6 Str.trans method it looks like it's working as expected:
say 'v^/\\'.trans( "\\^/v" => "." );
Outputs:
....
Reference:
https://perl6advent.wordpress.com/2010/12/21/day-21-transliteration-and-beyond/
Actually I'm working with Elm but I have few issues with the json parsing in this language, the error that give me the compiler is:
Err "Given an invalid JSON: Unexpected token \n in JSON at position 388"
What I need to do is this:
example
At the char_meta I want its something like this:
[("Biographical Information", [("Japanese Name", "緑谷出久"), ...]), ...]
Here the code:
Ellie link
PD: The only constant keys are character_name, lang, summary and char_meta, they keys inside of char_meta are dynamic (thats why I use keyvaluepair) and the length its always different of this array (sometimes its empty)
Thanks, hope can help me.
EDIT:
The Ellie link now redirect to the fixed code
The issue is that elm (or JS once transcoded) interprets the \n and \" sequences when parsing the string literal, and they are replaced with an actual new line and double quotes respectively, which results in invalid JSON.
If you want to have the JSON inline in the code, you need to escape the 5 \s by doubling them (\\n and \\").
This only applies for literals, you won't have the issue if you load JSON from the network for instance.
How can I ignore text inside double quote in antlr 2 .
for example:
I want to ignore "something random" , "some another random" type text which is inside double quote . How can I do this without my parser failing .
You could do what antlr would do for an XML parser:
form island grammars and lexer modes.
Note that this only works if there are no nested quotes:
As soon as you encounter a " you do a pushmode action and switch to a mode that skips everything except ", and switch back to regular when you see another ". This isn't elegant but should work rather well.
I am trying to use a copy command for Windows and we have directories such as c:\oracle.
While trying to execute one such, we get the following error:
source_file=folder+"\"
^
SyntaxError: Lexical error at line 17, column 23. Encountered: "\r" (13), after : ""
Here folder is my path of c:\oracle and while trying to add file to it like:
source=folder+"\"+src_file
I am not able to do so. Any suggestion on how to solve this issue?
I tried with / but my copy windows calling source in os.command is getting "the syntax is incorrect" and the only way to solve it is to use \ but I am getting the above error in doing so.
Please suggest. Thanks for your help
Thanks.
Short answer:
You need:
source_file = folder + "\\" + src_file
Long answer:
The problem with
source_file = folder + "\" + src_file
is that \ is the escape character. What it's doing in this particular case is escaping the " so that it's treated as a character of the string rather than the string terminator, similar to:
source_file = folder + "X + src_file
which would have the same problem.
In other words, you're trying to construct a string consisting of ", some other text and the end of line (\r, the carriage return character). That's where your error is coming from:
Encountered: "\r" (13)
Paxdiablo is absolutely correct about why \ isn't working for you. However, you could also solve your problem by using os.path.normpath instead of trying to construct the proper platform-specific path characters yourself.
In all programming languages I know of, you can't put a quote inside a string like this: "this is a quote: "." The reason for this is that the first quote opens the string, the second then closes it (!), and then the third one opens another string - with the following two problems:
whatever is between the quotes #2 and #3 is probably not valid code;
the quote #3 is probably not being closed.
There are two common mechanisms of solving this: doubling and escaping. Escaping is far more common, and what it means is you put a special character (usually \) in front of characters that you don't want to be interpreted in their usual value. Thus, "no, *this* is a quote: \"." is a proper string, where the quote #2 is not closing the string - and the character \ does not appear.
However, now you have another problem - how do you actually make the escape character appear in a string? Simple: escape it! "This is an escape: \\!" is how you do it: the backslash #1 is the escape character, and the backslash #2 is the escapee: it will not be interpreted with its usual escape semantics, but as a simple backslash character.
Thus, your line should say this:
source=folder+"\\"+src_file
BTW: upvote for both #paxdiablo (who got in before my diatribe) and #Nick (who has a proper Pythonic way to do what you want to do)