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diff --git a/docs/internals/input b/docs/internals/input deleted file mode 100644 index 9a7506ee2337..000000000000 --- a/docs/internals/input +++ /dev/null @@ -1,350 +0,0 @@ -# @(#)input 5.5 (Berkeley) 7/2/94 - -MAPS, EXECUTABLE BUFFERS AND INPUT IN EX/VI: - -The basic rule is that input in ex/vi is a stack. Every time a key which -gets expanded is encountered, it is expanded and the expansion is treated -as if it were input from the user. So, maps and executable buffers are -simply pushed onto the stack from which keys are returned. The exception -is that if the "remap" option is turned off, only a single map expansion -is done. I intend to be fully backward compatible with this. - -Historically, if the mode of the editor changed (ex to vi or vice versa), -any queued input was silently discarded. I don't see any reason to either -support or not support this semantic. I intend to retain the queued input, -mostly because it's simpler than throwing it away. - -Historically, neither the initial command on the command line (the + flag) -or the +cmd associated with the ex and edit commands was subject to mapping. -Also, while the +cmd appears to be subject to "@buffer" expansion, once -expanded it doesn't appear to work correctly. I don't see any reason to -either support or not support these semantics, so, for consistency, I intend -to pass both the initial command and the command associated with ex and edit -commands through the standard mapping and @ buffer expansion. - -One other difference between the historic ex/vi and nex/nvi is that nex -displays the executed buffers as it executes them. This means that if -the file is: - - set term=xterm - set term=yterm - set term=yterm - -the user will see the following during a typical edit session: - - nex testfile - testfile: unmodified: line 3 - :1,$yank a - :@a - :set term=zterm - :set term=yterm - :set term=xterm - :q! - -This seems like a feature and unlikely to break anything, so I don't -intend to match historic practice in this area. - -The rest of this document is a set of conclusions as to how I believe -the historic maps and @ buffers work. The summary is as follows: - -1: For buffers that are cut in "line mode", or buffers that are not cut - in line mode but which contain portions of more than a single line, a - trailing <newline> character appears in the input for each line in the - buffer when it is executed. For buffers not cut in line mode and which - contain portions of only a single line, no additional characters - appear in the input. -2: Executable buffers that execute other buffers don't load their - contents until they execute them. -3: Maps and executable buffers are copied when they are executed -- - they can be modified by the command but that does not change their - actions. -4: Historically, executable buffers are discarded if the editor - switches between ex and vi modes. -5: Executable buffers inside of map commands are expanded normally. - Maps inside of executable buffers are expanded normally. -6: If an error is encountered while executing a mapped command or buffer, - the rest of the mapped command/buffer is discarded. No user input - characters are discarded. -7: Characters in executable buffers are remapped. -8: Characters in executable buffers are not quoted. - -Individual test cases follow. Note, in the test cases, control characters -are not literal and will have to be replaced to make the test cases work. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -1: For buffers that are cut in "line mode", or buffers that are not cut - in line mode but which contain portions of more than a single line, a - trailing <newline> character appears in the input for each line in the - buffer when it is executed. For buffers not cut in line mode and which - contain portions of only a single line, no additional characters - appear in the input. - -=== test file === -3Gw -w -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -=== end test file === - - If the first line is loaded into 'a' and executed: - -1G"ayy@a - - The cursor ends up on the '2', a result of pushing "3Gw^J" onto - the stack. - - If the first two lines are loaded into 'a' and executed: - -1G2"ayy@a - - The cursor ends up on the 'f' in "foo" in the fifth line of the - file, a result of pushing "3Gw^Jw^J" onto the stack. - - If the first line is loaded into 'a', but not using line mode, - and executed: - -1G"ay$@a - - The cursor ends up on the '1', a result of pushing "3Gw" onto - the stack - - If the first two lines are loaded into 'a', but not using line mode, - and executed: - -1G2"ay$@a - - The cursor ends up on the 'f' in "foo" in the fifth line of the - file, a result of pushing "3Gw^Jw^J" onto the stack. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -2: Executable buffers that execute other buffers don't load their - contents until they execute them. - -=== test file === -cwLOAD B^[ -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -@a@b -"byy -=== end test file === - - The command is loaded into 'e', and then executed. 'e' executes - 'a', which loads 'b', then 'e' executes 'b'. - -5G"eyy6G"ayy1G@e - - The output should be: - -=== output file === -cwLOAD B^[ -LOAD B 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -@a@b -"byy -=== end output file === - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -3: Maps and executable buffers are copied when they are executed -- - they can be modified by the command but that does not change their - actions. - - Executable buffers: - -=== test file === -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -@a@b -"eyy -cwEXECUTE B^[ -=== end test file === - -4G"eyy5G"ayy6G"byy1G@eG"ep - - The command is loaded into 'e', and then executed. 'e' executes - 'a', which loads 'e', then 'e' executes 'b' anyway. - - The output should be: - -=== output file === -line 1 foo bar baz -EXECUTE B 2 foo bar baz -line 3 foo bar baz -@a@b -"eyy -cwEXECUTE B^[ -line 1 foo bar baz -=== end output file === - - Maps: - -=== test file === -Cine 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -=== end test file === - - Entering the command ':map = :map = rB^V^MrA^M1G==' shows that - the first time the '=' is entered the '=' map is set and the - character is changed to 'A', the second time the character is - changed to 'B'. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -4: Historically, executable buffers are discarded if the editor - switches between ex and vi modes. - -=== test file === -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -cwCHANGE^[Q:set -set|visual|1Gwww -=== end test file === - -vi testfile -4G"ayy@a - -ex testfile -$p -yank a -@a - - In vi, the command is loaded into 'a' and then executed. The command - subsequent to the 'Q' is (historically, silently) discarded. - - In ex, the command is loaded into 'a' and then executed. The command - subsequent to the 'visual' is (historically, silently) discarded. The - first set command is output by ex, although refreshing the screen usually - causes it not to be seen. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -5: Executable buffers inside of map commands are expanded normally. - Maps inside of executable buffers are expanded normally. - - Buffers inside of map commands: - -=== test file === -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -cwREPLACE BY A^[ -=== end test file === - -4G"ay$:map x @a -1Gx - - The output should be: - -=== output file === -REPLACE BY A 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -cwREPLACE BY A^[ -=== end output file === - - Maps commands inside of executable buffers: - -=== test file === -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -X -=== end test file === - -:map X cwREPLACE BY XMAP^[ -4G"ay$1G@a - - The output should be: - -=== output file === -REPLACE BY XMAP 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -X -=== end output file === - - Here's a test that does both, repeatedly. - -=== test file === -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -X -Y -cwREPLACED BY C^[ -blank line -=== end test file === - -:map x @a -4G"ay$ -:map X @b -5G"by$ -:map Y @c -6G"cy$ -1Gx - - The output should be: - -=== output file === -REPLACED BY C 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -X -Y -cwREPLACED BY C^[ -blank line -=== end output file === - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -6: If an error is encountered while executing a mapped command or - a buffer, the rest of the mapped command/buffer is discarded. No - user input characters are discarded. - -=== test file === -line 1 foo bar baz -line 2 foo bar baz -line 3 foo bar baz -:map = 10GcwREPLACMENT^V^[^[ -=== end test file === - - The above mapping fails, however, if the 10G is changed to 1, 2, - or 3G, it will succeed. - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -7: Characters in executable buffers are remapped. - -=== test file === -abcdefghijklmnnop -ggg -=== end test file === - -:map g x -2G"ay$1G@a - - The output should be: - -=== output file === -defghijklmnnop -ggg -=== end output file === - -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -8: Characters in executable buffers are not quoted. - -=== test file === -iFOO^[ - -=== end test file === - -1G"ay$2G@a - - The output should be: - -=== output file === -iFOO^[ -FOO -=== end output file === -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= |