Hi Ed,
On 06.01.2017 17:49, Edmond Kemokai wrote:
> The issue seems to go away after I quote the string.
If you supplied a Javascript encoded string to the Nashorn
ScriptEngineFactory.getOutputStatement()
you removed the cause of demonstrating that Nashorn ScriptEngineFactory creates
wrong output statements!
The problem is that Nashorn's ScriptEngineFactory.getOutputStatement() does not
analyze the received
string (which may be any sequence of characters) to see whether escaping needs
to take place (e.g.
containing quotes or backslashes) and finally enquoting the received (maybe
escape processed) string
to make it acceptable as an argument to its print() function!
The task at hand is to create an output statement that will be able to output
the received string as
is (no matter what the string contains), character by character!
---
Background: the JSR-223/javax.script package was *not* created with a specific
scripting language in
mind. A scripting factory cannot assume that a supplied string adheres to the
specific rules of that
particular scripting language. The getOutputStatement() method is there to get
an output statement
adhering to the syntax rules of the script language that outputs (shows) the
string exactly as
received, character by character! Each script language may have different
syntax, escaping rules
etc., therefore the ScriptEngineFactory knowing its ScriptEngines syntax and
rules is asked to
create a proper output statement.
It is the script factory's responsibility to analyze the received string and to
escape characters in
order to have the script engine output the string exactly as received,
character by character.
To test this, my test program feeds any available javax.script language with a
string containing
quotes around the script engine name (to test quote escaping) and has the
script engine take its own
medicine by executing the returned output statement.
In the case of Nashorn the script engine is not able to reliably run the output
statement generated
by its own ScriptEngineFactory!
So, if getOutputStatement() receives the following string value to output:
abc "def" ghi
it needs to analyze and in this case escape the string first to match the rules
of JavaScript:
abc \"def\" ghi
and then produce the output statement by enquoting the escaped string:
print("abc \"def\" ghi")
This way, this statement can be run correctly by Nashorn and it gives exactly
the received string as
output:
abc "def" ghi
Also in the case of Nashorn/Javascript I would add a trailing '\n' character as
usually script
engine's output statements supply a trailing new line character. However, this
is not
defined/mandated and left to the implementation.
---rony
P.S.: The Rexx/ooRexx ScriptEngineFactory would create the following output
statement and be able to
successfully run it, yielding exactly the string that was supplied to
getOutputStatement():
say "abc ""def"" ghi"
running that statement yields the output:
abc "def" ghi
(The Rexx/ooRexx language escapes quotes in strings by doubling them.)
> You can run the code in the browser by right clicking and choosing "Test"
> then click "Run". On the
> top right, click the dropdown button and choose "Log Viewer" to see the
> output.
>
>
>
> Ouput:
>
> INFO Invocation - ---> language [ECMAScript]:
> ---------------------------------------->
>
> INFO Invocation - 1) output statement to process:
> "hello world, this is
> ECMAScript speaking! "
>
> INFO Invocation - --> testing
> getOutputStatement(String)
> INFO Invocation - , produced the following [ECMAScript]
> output statement
>
> print("hello world, this is ECMAScript speaking! ")
>
> INFO Invocation - ... now running "eval(code)" using
> the scripting engine
> [ECMAScript]:
>
>
> INFO Invocation -
>
> INFO Invocation - 2) testing
> getMethodCallSyntax(obj, meth, arg...)
> INFO Invocation - , produced the following [ECMAScript]
> method call statement:
>
> object.method(arg1,arg2)
>
> INFO Invocation - 3) testing getProgram(String...)
> INFO Invocation - produced the following [ECMAScript]
> program:
>
> print("hello world, this is ECMAScript speaking! ");object.method(arg1,arg2);
>
> INFO Invocation - <--- end of testing language
> [ECMAScript].
> <----------------------------------------
>
>
>
>
> On Fri, Jan 6, 2017 at 10:21 AM, Rony G. Flatscher <rony.flatsc...@wu.ac.at
> <mailto:rony.flatsc...@wu.ac.at>> wrote:
>
> Hi Ed,
>
> On 06.01.2017 16:07, Edmond Kemokai wrote:
>>
>> I am the developer of HiveMind, it is a web app platform that relies
>> entirely on scripting
>> engines via JSR-223.
>>
>> You can access a demo instance: http://demo.crudzilla.com:7000/
>> <http://demo.crudzilla.com:7000/>
>> Login with: developer/developer
>>
>> I have created a test file in:
>> /com/crudzilla/cloudTest/web/rony-groovy.ste
>>
>> Put your code (the original one you pasted) in there and save, I'll take
>> a look to see what
>> might be missing.
> Done.
>
> After compiling just run it as "java RunScript" (make sure your CLASSPATH
> picks up the
> directory that contains RunScript.class, which does not define any
> package name, e.g. "."). It
> will list all JSR-223 scripting languages on your system and give the
> help. E.g. currently on
> my Windows system:
>
> F:\work\svn\bsf4oorexx\trunk\samples\Java\javax.script>java RunScript
> The following javax.script engines are currently available:
>
> ECMAScript
> ooRexx
>
> usage: java RunScript [{-i | -t | -e enginename filename [args...] |
> filename [args...]}]
>
> ... no arguments lists the available javax.script engines
> -h ... 'help', gives this usage text
> -i ... lists the available javax.script engines and informs
> about their properties
> -t ... lists the available javax.script engines and tests
> evaluating their
> "getOutputStatement(String)" method
> -e enginename filename [args...] ... uses "enginename" to
> evaluate "filename"
> supplying the arguments "args..."
> filename [args...] ... the "filename" extension determines the
> script engine to
> evaluate it, supplying the arguments "args..."
>
> Running with the "-t" switch tests the code generated by the script
> engine's factories by
> letting it eval()'ed.
>
> ---rony
>
>
>
>>
>>
>> On Fri, Jan 6, 2017 at 9:07 AM, Rony G. Flatscher
>> <rony.flatsc...@wu.ac.at
>> <mailto:rony.flatsc...@wu.ac.at>> wrote:
>>
>> Besides Java 1.8.0_111 the problem exists in 9ea-+134 (engine
>> version: "9ea", language
>> version:
>> "ECMA 262 - Edition 5.1" ) as well: Nashorn's javax.script factory
>> is used to get an output
>> statement and then it is used to execute it:
>>
>> ---> language [ECMAScript]:
>> ---------------------------------------->
>>
>> 1) output statement to process: hello world, this is
>> "ECMAScript" speaking!
>>
>> --> testing getOutputStatement(String), produced the
>> following [ECMAScript]
>> output statement
>>
>> print(hello world, this is "ECMAScript" speaking! )
>>
>> ... now running "eval(code)" using the scripting engine
>> [ECMAScript]:
>>
>>
>> javax.script.ScriptException: <eval>:1:12 Expected , but found
>> world
>> print(hello world, this is "ECMAScript" speaking! )
>> ^ in <eval> at line number 1 at column number 12
>> while eval() the code:
>> print(hello
>> world, this is "ECMAScript" speaking! )
>>
>> This time trying to not format the Java code, so hopefully the
>> mailer will not render it
>> illegible:
>>
>> ... cut ...
>>
>> // create an output statement and execute output statement
>> with the script engine
>> static void testEngine(String name, ScriptEngineFactory sef,
>> ScriptEngine se)
>> {
>> System.out.println("---> language ["+name+"]:
>> ---------------------------------------->\n");
>> String text="hello world, this is \""+name+"\" speaking!
>> ";
>> String code=sef.getOutputStatement(text);
>> System.out.println("\t1) output statement to process:
>> "+text+"\n");
>>
>> System.out.print("\t--> testing
>> getOutputStatement(String)");
>> System.out.println(", produced the following ["+name+"]
>> output statement
>> \n\n"+code+"\n");
>> System.out.println("\t... now running \"eval(code)\"
>> using the scripting engine
>> ["+name+"]: \n\n");
>> try
>> {
>> se.eval(code);
>> System.out.println("\n");
>> }
>> catch (ScriptException sexc)
>> {
>> System.err.println(sexc+" while eval() the code:
>> "+code+"\n");
>> }
>>
>> System.out.print("\t2) testing getMethodCallSyntax(obj,
>> meth, arg...)");
>> String methCode=sef.getMethodCallSyntax("object",
>> "method", "arg1", "arg2");
>> System.out.println(", produced the following ["+name+"]
>> method call statement:
>> \n\n"+methCode+"\n");
>>
>> System.out.print("\t3) testing getProgram(String...)");
>> String programCode=sef.getProgram(code, methCode);
>> System.out.println(" produced the following ["+name+"]
>> program:
>> \n\n"+programCode+"\n");
>>
>> System.out.println("<--- end of testing language
>> ["+name+"].
>> <----------------------------------------\n");
>> }
>>
>> ... cut ...
>>
>> If I should file a bug then please advise where and how.
>>
>> ---rony
>>
>>
>> On 08.12.2016 16:17, Rony G. Flatscher wrote:
>> > Unfortunately, the mailing list seems to behave as if it was
>> running in the 1970's such
>> that the
>> > formatted text (indented, partially colorized and formatted to
>> preformat and Courier)
>> has turned to
>> > become illegible, unfortunately (using the Thunderbird e-Mail
>> client)!
>> > :(
>> >
>> > The meat is right in the first two paragraphs and the last
>> paragraph before the
>> signature. Should
>> > anyone be interested in the Java-utility, please drop me a
>> personal e-mail and I will
>> send that Java
>> > program as an attachment to you.
>> >
>> > ---rony
>> >
>> >
>>
