Lexical-to-value mapping is not a "partial mapping"

[hartig]

This issue is about the following sentence in Sec.7 of RDF Semantics.

A datatype is understood to define a partial mapping, called the lexical-to-value mapping, from a lexical space (a set of character strings) to values.

This sentence is incorrect in the sense that, by the definition of the notion of a lexical-to-value mapping in RDF Concepts, it is not a partial mapping but a total mapping (or, simply, a function). The relevant part of the definition is that is says: "Each member of the lexical space is paired with ..."

Related to this issue, the following sentence (in the same paragraph as the one quoted above) is also not particularly accurate.

An ill-typed literal is one whose datatype IRI is recognized, but whose character string is assigned no value by the lexical-to-value mapping for that datatype.

To fix this issue, I suggest to change the first sentence quoted above as follows:

A datatype is understood to define a function, called the lexical-to-value mapping, from a lexical space (a set of character strings) to values.

And the second sentence quoted above may be changed as follows:

An ill-typed literal is one whose datatype IRI is recognized, but whose character string is not in the lexical space of the datatype identified by that IRI and, thus, is not in the domain of the lexical-to-value mapping of that datatype.

[afs]

A datatype is understood to define a function, called the lexical-to-value mapping, from a lexical space (a set of character strings) to values.

Minor tweaking: maybe "character string" could be RDF strings). This avoids "character". An "RDF String" is a sequences of Unicode scale values -- all codepoints except the surrogates.

Unicode D76:
"Unicode scalar value: Any Unicode code point except high-surrogate and low-surrogate code points."

[pfps]

Yeah the wording needs to be improved. I think the best thing is to defer more to RDF Concepts.

[hartig]

Minor tweaking: maybe "character string" could be RDF strings).

While I agree, I see this as a separate issue because it is not only in this particular sentence. Instead, the term "character string" appears multiple times in the paragraph in which this sentence is.

[hartig]

Yeah the wording needs to be improved. I think the best thing is to defer more to RDF Concepts.

I agree. There is quite a bit of repetition here in terms of things that are already in RDF Concepts.

[afs]

The paragraph also needs #64 which adds that rdf:dirLangString is an exception, along side rdf:langString.