Adding to the story …
I changed the type for the A, B, and C elements to xs:string:
<xs:element name="test">
<xs:complexType>
<xs:sequence dfdl:separator="/" dfdl:separatorPosition="infix"
dfdl:separatorSuppressionPolicy="anyEmpty">
<xs:element name="A" type="xs:string" dfdl:lengthKind="pattern"
dfdl:lengthPattern="A"/>
<xs:element name="B" minOccurs="0"
dfdl:occursCountKind="implicit"
type="xs:string"
dfdl:lengthKind="pattern"
dfdl:lengthPattern="B"/>
<xs:element name="C" type="xs:string" dfdl:lengthKind="pattern"
dfdl:lengthPattern="C"/>
</xs:sequence>
</xs:complexType>
</xs:element>
With this input:
A/C
I get this error:
Parse Error: Separator '/' not found
I conclude that:
1. anyEmpty does not work.
2. There is an illogical dependency in the DFDL language between
lengthPattern and separatorSuppressionPolicy="anyEmpty"
Do you agree?
/Roger
From: Roger L Costello <coste...@mitre.org>
Sent: Friday, February 4, 2022 12:31 PM
To: users@daffodil.apache.org; mbecke...@apache.org
Subject: RE: Doesn't separatorSuppressionPolicy=trailingEmpty mean the input
can suppress (omit) separators?
Let me elaborate on my last email.
If I use lengthPattern and don’t specify <dfdl:assert test="{ . ne '' }"/> then
the schema will erroneously accept this input:
A//C
If I do use lengthPattern and do specify <dfdl:assert test="{ . ne '' }"/> then
the DFDL does not allow me to have this input:
A/C
There is (in my view) an illogical dependency in the DFDL language between
lengthPattern and separatorSuppressionPolicy="anyEmpty"
Do you agree?
/Roger
From: Roger L Costello <coste...@mitre.org<mailto:coste...@mitre.org>>
Sent: Friday, February 4, 2022 12:23 PM
To: users@daffodil.apache.org<mailto:users@daffodil.apache.org>;
mbecke...@apache.org<mailto:mbecke...@apache.org>
Subject: Re: Doesn't separatorSuppressionPolicy=trailingEmpty mean the input
can suppress (omit) separators?
Thanks Mike. I changed my schema to separatorSuppressionPolicy="anyEmpty" and
now I get this error:
Parse Error: Assertion failed: { . ne '' } failed
It appears that if a schema uses lengthPattern, then the schema cannot use
separatorSuppressionPolicy="anyEmpty". Do agree?
/Roger
From: Mike Beckerle <mbecke...@apache.org<mailto:mbecke...@apache.org>>
Sent: Friday, February 4, 2022 12:04 PM
To: users@daffodil.apache.org<mailto:users@daffodil.apache.org>
Subject: [EXT] Re: Doesn't separatorSuppressionPolicy=trailingEmpty mean the
input can suppress (omit) separators?
That B middle element is not "trailing". Element C, after it, is required, so B
can never be trailing.
You want separatorSuppressionPolicy='anyEmpty' which means any empty element
wherever it is located is suppressed. Note that this very often goes with
non-positional formats, i.e., formats that have initiators so that whether an
element is B or C can be distinguished by looking at the data stream.
With trailing suppression of separators, you can use position, i.e., can
determine which element declaration applies by counting the separators. With
'anyEmpty' suppression of separators, counting isn't sufficient any more.
On Fri, Feb 4, 2022 at 11:55 AM Roger L Costello
<coste...@mitre.org<mailto:coste...@mitre.org>> wrote:
Hi Folks,
My input consists of 3 data items separated by slash, e.g.,
A/B/C
The middle data item is optional.
If there is no data for the middle data item, I want the separator suppressed
(omitted), so I use separatorSuppressionPolicy="trailingEmpty". I expect this
to be the appropriate input:
A/C
Is that correct?
When I run my DFDL schema I get this error:
Parse Error: Separator '/' not found
When I use this input:
A//C
There is no error.
I'm confused. I thought separatorSuppressionPolicy="trailingEmpty" means that I
can suppress (omit) the separator when there is no data available. What am I
failing to understand? Below is my DFDL schema. /Roger
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:dfdl="http://www.ogf.org/dfdl/dfdl-1.0/";
xmlns:xs="http://www.w3.org/2001/XMLSchema";>
<xs:annotation>
<xs:appinfo source="http://www.ogf.org/dfdl/";>
<dfdl:format textBidi="no" floating="no"
encodingErrorPolicy="replace" outputNewLine="%CR;%LF;" leadingSkip="0"
trailingSkip="0" alignment="1" alignmentUnits="bytes" textPadKind="none"
textTrimKind="none" truncateSpecifiedLengthString="no" escapeSchemeRef=""
representation="text" encoding="ASCII" lengthKind="delimited"
initiator="" terminator="" ignoreCase="yes" sequenceKind="ordered" separator=""
initiatedContent="no" emptyValueDelimiterPolicy="none" fillByte="%SP;"
textNumberRep="standard" textStandardBase="10"
textStandardZeroRep="0" textNumberRounding="pattern"
textStandardExponentRep="E" textNumberCheckPolicy="strict"
lengthUnits="characters" nilKind="literalValue" nilValue="-"
nilValueDelimiterPolicy="none"
separatorSuppressionPolicy="trailingEmptyStrict"/>
</xs:appinfo>
</xs:annotation>
<xs:element name="test">
<xs:complexType>
<xs:sequence dfdl:separator="/" dfdl:separatorPosition="infix"
dfdl:separatorSuppressionPolicy="trailingEmpty">
<xs:element name="A" type="non-zero-length-string"
dfdl:lengthPattern="A"/>
<xs:element name="B" minOccurs="0"
dfdl:occursCountKind="implicit"
type="non-zero-length-string"
dfdl:lengthPattern="B"/>
<xs:element name="C" type="non-zero-length-string"
dfdl:lengthPattern="C"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:simpleType name="non-zero-length-string" dfdl:lengthKind="pattern">
<xs:annotation>
<xs:appinfo source="http://www.ogf.org/dfdl/";>
<dfdl:assert test="{ . ne '' }"/>
</xs:appinfo>
</xs:annotation>
<xs:restriction base="xs:string"/>
</xs:simpleType>
</xs:schema>
