Connected: An Internet Encyclopedia
3.1.4. STRUCTURED FIELD BODIES

Up: Connected: An Internet Encyclopedia
Up: Requests For Comments
Up: RFC 822
Up: 3. LEXICAL ANALYSIS OF MESSAGES
Up: 3.1. GENERAL DESCRIPTION
Prev: 3.1.3. UNSTRUCTURED FIELD BODIES
Next: 3.2. HEADER FIELD DEFINITIONS

3.1.4. STRUCTURED FIELD BODIES

3.1.4. STRUCTURED FIELD BODIES

To aid in the creation and reading of structured fields, the free insertion of linear-white-space (which permits folding by inclusion of CRLFs) is allowed between lexical tokens. Rather than obscuring the syntax specifications for these structured fields with explicit syntax for this linear-white-space, the existence of another "lexical" analyzer is assumed. This analyzer does not apply for unstructured field bodies that are simply strings of text, as described above. The analyzer provides an interpretation of the unfolded text composing the body of the field as a sequence of lexical symbols.

These symbols are:

The first four of these symbols are self-delimiting. Atoms are not; they are delimited by the self-delimiting symbols and by linear-white-space. For the purposes of regenerating sequences of atoms and quoted-strings, exactly one SPACE is assumed to exist, and should be used, between them. (Also, in the "Clarifications" section on "White Space", below, note the rules about treatment of multiple contiguous LWSP-chars.)

So, for example, the folded body of an address field

            ":sysmail"@  Some-Group. Some-Org,
            Muhammed.(I am  the greatest) Ali @(the)Vegas.WBA

is analyzed into the following lexical symbols and types:

                    :sysmail              quoted string
                    @                     special
                    Some-Group            atom
                    .                     special
                    Some-Org              atom
                    ,                     special
                    Muhammed              atom
                    .                     special
                    (I am  the greatest)  comment
                    Ali                   atom
                    @                     atom
                    (the)                 comment
                    Vegas                 atom
                    .                     special
                    WBA                   atom

The canonical representations for the data in these addresses are the following strings:

                        ":sysmail"@Some-Group.Some-Org

and

                            Muhammed.Ali@Vegas.WBA


Next: 3.2. HEADER FIELD DEFINITIONS

Connected: An Internet Encyclopedia
3.1.4. STRUCTURED FIELD BODIES