LSE allows you to use its knowledge of programming languages to
develop software. LSE also allows you to design your own languages.
In addition to programming languages, you can define languages for
other things, such as memos or letters. Once you have defined a
language, you can save it in an environment file and recall it for
subsequent editing and update sessions.
To create a new language, you first create a source file (.LSE),
within LSE, into which you put the LSE commands that define the
elements of your language. Once the source file is completed, use
the DO command to process the definitions. You may then use the SAVE
ENVIRONMENT command to save the definitions in binary form for
subsequent use by LSE. For example, to create a file for a new
language, you do the following:
1. Create a source file in an empty buffer, with a .LSE
extension.
2. Put all language, token, and placeholder definitions
in the source file.
3. Execute the commands in the source file by executing
a DO command (to load the definitions for the current
editing session).
4. Execute a SAVE ENVIRONMENT command to save your new
language definitions in a binary file (.ENV), for
subsequent use.
Thus, to create a binary image file (.ENV) for your language, you use
the following sequence of commands:
LSE> DO
LSE> SAVE ENVIRONMENT filename
LSE> EXIT
1 – Defining a Language
All template definitions, whether text or language-oriented, begin
with a language definition command (DEFINE LANGUAGE) that specifies
language characteristics. For example, to define a language, you use
the DEFINE LANGUAGE command to specify:
1. The name of your language (DEFINE LANGUAGE).
2. The file types (/FILE_TYPES) for the language.
3. The identifier characters to be used in token and
alias names (/IDENTIFER_CHARACTERS).
4. The punctuation and delimiter characters
(/PUNCTUATION_CHARACTERS).
5. The required and optional placeholder delimiters
(/OPT, /OPTL, /REQ, /REQL).
6. The initial text heading for the new file
(/INITIAL_STRING).
7. The indentation control for tokens and placeholders
(/TAB_INCREMENT).
Example:
DEFINE LANGUAGE MEMO -
/IDENTIFIER CHARACTERS = -
"abcd....XYZ0123456789" -
/INITIAL_STRING ={memo_template}" -
/FILE_TYPES = (.MEMO) -
/TAB_INCREMENT = 4 -
/OPT = ("[","]") -
/OPTL = ("[","]...") -
/PUNCTUATION_CHARACTERS = ".,':*+-/" -
/REQ = ("[","]") -
/REQL = ("[","]...") -
To define a placeholder, you use the DEFINE PLACEHOLDER command to
specify:
1. The name of your placeholder (DEFINE PLACEHOLDER).
2. The associated language (/LANGUAGE).
3. The type of placeholder: terminal, nonterminal, or menu
(/TYPE).
4. The description that you want displayed when the placeholder
is used in a menu or in the SHOW PLACEHOLDER command.
5. The end of the placeholder definition (END DEFINE).
Example:
.
.
DEFINE PLACEHOLDER subject_line -
/LANGUAGE = MEMO -
/TYPE = TERMINAL -
"Subject of the memo."
END DEFINE
To define a token you use the DEFINE TOKEN command to specify:
1. The name of your token (DEFINE TOKEN).
2. The associated language (/LANGUAGE).
3. The description that you want displayed when the token
is used in a menu or in the SHOW TOKEN command.
4. The end of the token definition (END DEFINE).
Example:
.
.
DEFINE TOKEN location -
/LANGUAGE = MEMO -
/DESCRIPTION = "Office location"
"LOC: URE-0096"
END DEFINE
2 – Language Commands
LSE provides the following commands for creating and manipulating
language elements:
DEFINE ALIAS [/LANGUAGE=name]
specifies the alias name to be defined in the specified
language.
DEFINE LANGUAGE name
specifies characteristics for the current language.
DEFINE PLACEHOLDER [/LANGUAGE=name]
specifies placeholder characteristics for the specified
language.
DEFINE TOKEN [/LANGUAGE=name]
specifies token characteristics for the specified language.
DELETE ALIAS [/LANGUAGE=name]
cancels the effect of a DEFINE ALIAS command used for the
specified language.
DELETE LANGUAGE name
cancels the effect of a DEFINE LANGUAGE command.
DELETE PLACEHOLDER [/LANGUAGE=name]
cancels the effects of a DEFINE PLACEHOLDER command used for
the specified language.
DELETE TOKEN [/LANGUAGE=name]
cancels the effect of DEFINE TOKEN command used in the
specified language.
DO
executes LSE commands or VAXTPU program statements.
END DEFINE
terminates a DEFINE TOKEN or DEFINE PLACEHOLDER command.
EXTRACT LANGUAGE language-name
selects the definition of the named language and formats it
as a command.
HELP/LANGUAGE [name | * ]
displays help information about the specified language.
MODIFY LANGUAGE name
modifies the characteristics of a specified language.
SAVE ENVIRONMENT file-spec
writes all user-defined languages, tokens, and placeholders
to a specified file.
SHOW ALIAS name [/LANGUAGE=name]
displays the characteristics of the specified alias for the
specified language.
SHOW LANGUAGE [ name | * ]
displays the characteristics of the specified language.
SHOW TOKEN name [/LANGUAGE=name]
displays the characteristics of the specified token for the
specified language.
SHOW PLACEHOLDER name [/LANGUAGE=name]
displays the characteristics of the specified placeholder for
the specified language.