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Diffstat (limited to 'usr.bin/vi/docs/internals/structures')
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diff --git a/usr.bin/vi/docs/internals/structures b/usr.bin/vi/docs/internals/structures deleted file mode 100644 index d49ab65cbeed..000000000000 --- a/usr.bin/vi/docs/internals/structures +++ /dev/null @@ -1,61 +0,0 @@ -# @(#)structures 5.2 (Berkeley) 11/1/93 - -There are three major data structures in this package. The first is a -single global structure (named GS) which contains information common to -all files and screens. It's really pretty tiny, and functions more as a -single place to hang things than anything else. - -The second and third structures are the file structures (named EXF) and -the screen structures (named SCR). They contain information theoretically -unique to a screen or file, respectively. Each SCR structure has a set -of functions which update the screen and/or return information about the -screen from the underlying screen package. - -The GS structure contains linked lists SCR structures. The structures -can also be classed by persistence. The GS structure never goes away -and the SCR structure persists over instances of files. - -File names have different properties than files themselves, so the name -information for a file is held in an FREF structure which is chained from -the SCR structure. - -In general, functions are always passed an SCR structure and often an EXF -structure as well. The SCR structure is necessary for any routine that -wishes to talk to the screen, the EXF structure is necessary for any -routine that wants to modify the file. The relationship between an SCR -structure and its underlying EXF structure is not fixed, and although you -can translate from an SCR to the underlying EXF, it is discouraged. If -this becomes too onerous, I suspect I'll just stop passing around the EXF -in the future. - -The naming of the structures is consistent across the program. (Macros -even depend on it, so don't try and change it!) The global structure is -"gp", the screen structure is "sp", and the file structure is "ep". - -A few other data structures: - -TEXT In nvi/cut.h. This structure describes a portion of a line, - and is used by the input routines and as the "line" part of a - cut buffer. - -CB In nvi/cut.h. A cut buffer. A cut buffer is a place to - hang a list of TEXT structures. - -MARK In nvi/mark.h. A cursor position, consisting of a line number - and a column number. - -MSG In nvi/msg.h. A chain of messages for the user. - -SEQ In nvi/seq.h. An abbreviation or a map entry. - -EXCMDARG - In nvi/ex/excmd.h.stub. The structure that gets passed around - to the functions that implement the ex commands. (The main - ex command loop (see nvi/ex/ex.c) builds this up and then passes - it to the ex functions.) - -VICMDARG - In nvi/vi/vcmd.h. The structure that gets passed around to the - functions that implement the vi commands. (The main vi command - loop (see nvi/vi/vi.c) builds this up and then passes it to the - vi functions.) |