1.3.5. L2 Editor

Version II.0, February 1979

The L2 Editor is being released on an experimental basis. Not all options are yet fully implemented so this section may not be complete. The main advantage of this version is that it is able to handle files larger than can fit into the main memory buffer at one time; the upper limit being determined by the space available on disk. It also automatically makes a backup copy of the file being edited. In many respects this Editor works exactly as this release and displays the same prompt lines. Where the versions are the same, the user is directed to read the main Editor section.

Entering the Workfile and Getting a Program

If, on typing “E”, there is not enough room on the disk;

> ERROR: Not enough room for backup!

will be displayed. This disk must then be K(runched in order to provide room if that is possible, a file removed or another disk must be used. The backup file is always 'written' to disk with the original file data in it.

The same prompt line is displayed; see section 1.3.2.

1) With a name. If a file is chosen, a backup copy will be made before the file is available for editing.

Figure 5.1

Copying to filename.back.
> Edit
Reading....

After this series of prompt lines, the first part of the text will appear on the screen.

2) With a return. A new file is created in the same manner as in section 1.3.2.

The paragraphs on moving the cursor, Insert and Delete in section 1.3.2 should be read and are applicable here.

Leaving the Editor and Updating the Workfile

When all changes and additions have been made, the Editor is exited by typing “Q” and the following prompt is displayed.

Figure 5.2

>Quit:
     U(pdate the workfile and leave
     E(xit (but workfile not updated)
     R(eturn to the Editor without doing anything.

Notice that the Write option is no longer available. One of these three options must be chosen. See also Miscellaneous commands in section 1.3.3.

U(pdate:

This works in the same manner, however additional information is supplied indicating the name of file updated and the length.

When a new file is created, the following appears:

Figure 5.3

Writing.*
The workfile, *SYSTEM.WRK.TEXT, is nnn blocks long.

When an existing file has been used, this example shows the extra information now given:

Figure 5.4

Writing.*
The workfile, *X:F1.TEXT, is 44 blocks long.
The backup file is X:F1.BACK.

The newly edited file is referred to as .TEXT, while the .BACK file contains the original file with no modifications.

E(xit:

This causes the Editor to return to the command level without making any changes in the workfile. No .BACK file is made and the existing .BACK is removed. For example, if F1.TEXT is the file being used, then a copy F1.BACK will be made on entering the editor and on leaving by using the “E” command, F1.BACK will be removed and only F1.TEXT will remain. However, since F1.TEXT is a copy of the original, it will be in different place in the directory.

R(eturn:

This is the same. See section 1.3.3.

Moving Commands

Jump

Jump mode displays the same prompt line as before. In this case “B” and “E” refer to the beginning (end) of the buffer not the beginning (end) of the file.

Typing “M” causes the Editor to display:

Jump to what marker?

It is now possible to use 20 markers and these will be set in the same way as in section 1.3.3. To jump to the desired marker, type in the name. If the marker is present, the Editor will jump to that position, otherwise, the Editor will jump to the last position of the cursor in the file. If Find needs to search a section of the file, other than the buffer, Leaping..... will be displayed.

Banish

This is a new command and is reached by typing “B” at the Edit level. This is the prompt that will appear:

>Banish: To the L(eft or R(ight <esc>

Prior to doing a large insertion or copy, in order to provide more room in the buffer and avoid buffer overflow, it is possible to move characters from the buffer into the stack. There is a left and a right stack; left being ahead of the cursor and right, behind the cursor. The user can make the choice according to the current situation. In general, “some text” is saved after a banish, the screen is a rough boundary for this text.

Next

In order to move beyond the bounds of the buffer, type “N”. The following prompt will then be displayed:

Next: F(orwards, B(ackwards in the file; S(tart, E(nd of the file. <esc>

Choose one of the five options available. When using “F” or “B” an implicit banish occurs using the cursor as the point of reference. For example, when “F” is typed, everything above the top of the screen is banished to the left stack. More characters are added to the bottom of the screen to extend the buffer in the forward direction. When “B” is used the characters below the cursor are banished to the right stack and part of the screen will become blank. More characters are added above the ‘window’ of the screen.

Figure 5.5 Symbolic File

left stack
Backwards
Start Buffer right stack
Forward
End

Page

See section 1.3.3.

Equals

See section 1.3.3.

Text Changing Commands

Insert

See section 1.3.3.

Delete

See section 1.3.3.

Zap

See section 1.3.3.

Copy

See section 1.3.3.

Exchange

See section 1.3.3.

Find

Read section 1.3.3. The Editor will display: Finding..... and if the pattern is not in the buffer:

End of buffer encountered. Get more from disk? (Y/N)

On typing “Y”, the Editor will move another section of the file into the buffer to continue searching. Find is still directional. If the pattern is not found, in a full-file search, the cursor is left in an arbitrary position in the file.

Replace

See section 1.3.3.

Formatting Commands

Adjust

See section 1.3.3.

Margin

See section 1.3.3.

Miscellaneous Commands

Set

See section 1.3.3. The same prompt line is displayed.

M(arker:

Read section 1.3.3. The names of the markers can be seen by typing “SE” for Set Environment while at the Edit level. To set the marker, type “SM”. In the event that 20 markers have already been set, this will be indicated by:

Marker overflow. Which one to replace? (Type in the letter or <sp>)

E(nvironrnent:

To set the environment, type “SE”. The following is an example of the prompt displayed:

Figure 5.5
>Environment: options <etx> or <sp> to leave
   A(uto Indent  False
   F(illing      True
   L(eft margin  4
   R(ight margin 70
   P(ara margin  1
   C(ommand ch   ^
   S(et tabstops
   T(oken def    True
11582 bytes used. 2754 available. You have 86 pages of room, and at most 13 pages worth in the buffer.
Markers: <P1 P2 >P3
Created August 15, 1978: Last updated August 15, 1978 (Revision 1).

By typing the appropriate letter, any or all of the options can changed. See section 1.3.3. The arrow before the marker name indicates the relative position of the marker in the file to the buffer. No arrow indicates that the marker is in the current buffer.

It is now possible to vary the tabstops. Type “S” while in the environment and the following prompt will appear:

Set tabs: <right,left vectors> C(ol# N(o R(ight L(eft D(ecimal stop <etx>

At present, these are not yet fully implemented so that the effect of using any of them is to have a variable tabstop instead of being set at eight characters apart.

Verify

See section 1.3.3.

This page last regenerated Sun Jul 25 01:09:11 2010.