diff options
Diffstat (limited to 'docs/internals/structures')
| -rw-r--r-- | docs/internals/structures | 68 |
1 files changed, 0 insertions, 68 deletions
diff --git a/docs/internals/structures b/docs/internals/structures deleted file mode 100644 index a25c780c8e63..000000000000 --- a/docs/internals/structures +++ /dev/null @@ -1,68 +0,0 @@ -# @(#)structures 5.4 (Berkeley) 10/4/95 - -There are three major data structures in this package, plus a single data -structure per screen type. The first is a single global structure (GS) -which contains information common to all files and screens. It hold -global things like the input key queues, and functions as a single place -to hang things. For example, interrupt routines have to be able to find -screen structures, and they can only do this if they have a starting -point. The number of globals in nvi is dependent on the screen type, but -every screen type will have at least one global, __global_list, which -references the GS structure. - -The GS structure contains linked lists of screen (SCR) structures. -Each SCR structure normally references a file (EXF) structure. - -The GS 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 never goes away. The SCR structure persists over -instances of screens, and the EXF structure persists over references to -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, which usually -references an underlying EXF structure. 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 various ex commands will substitute a new EXF in place of the current -one, and there's no way to detect this. - -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. - -CL The curses screen private data structure. Everything to - do standalone curses screens. - -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. - -TK The Tcl/Tk screen private data structure. Everything to - do standalone Tcl/Tk screens. - -EXCMD In nvi/ex/ex.h. 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.) - -VICMD In nvi/vi/vi.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.) |