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Usage: LAST
Positions to the last record in a view.
See filing.db.
Usage: LCLOSE
Closes the device opened with LOPEN. The device is also closed automatically when a program ends.
Usage: b$=LEFT$(a$,x%)
Returns the leftmost x% characters from the string a$.
For example if n$ has the value Charles, then b$=LEFT$(n$,3) assigns Cha to b$.
Usage: a%=LEN(a$)
Returns the number of characters in a$.
E.g. if a$ has the value 34 Kopechnie Drive then LEN(a$) returns 18.
You might use this function to check that a data file string field is not empty before displaying:
IF LEN(A.client$)
PRINT A.client$
ENDIF
Usage: len&=LENALLOC(pcell&)
Returns the length of the previously allocated cell at pcell&. An error will be raised if the cell address argument is not in the range known by the heap.
See also SETFLAGS if you require a 64K memory limit to be enforced. If the flag is set to restrict the limit, len& is guaranteed to fit into an integer.
ARM
Cells are allocated lengths that are the smallest multiple of four greater than the size requested because the ARM processor requires a four-byte word alignment for its memory allocation. The ARM processor is used in the Psion Series 5 and other EPOC devices.
Usage: a=LN(x)
Returns the natural (base e) logarithm of x.
Use LOG to return the base 10 log of a number.
Usage: LOADM module$
Loads a translated OPL module so that procedures in that module can be called. Until a module is loaded with LOADM, calls to procedures in that module will give an error.
module$ is a string containing the name of the module. Specify the full file name only where necessary.
Example: LOADM "MODUL2"
Up to 8 modules can be in memory at any one time, including the top level module; if you try to LOADM a ninth module, you get an error. Use UNLOADM to remove a module from memory so that you can load a different one.
By default, LOADM always uses the folder of the top level module. It is not affected by the SETPATH command.
Usage: a%=LOC(a$,b$)
Returns an integer showing the position in a$ where b$ occurs, or zero if b$ doesn’t occur in a$. The search matches upper and lower case.
Example: LOC("STANDING","AND") would return the value 3 because the substring AND starts at the third character of the string STANDING.
Usage: LOCAL variables
Used to declare variables which can be referenced only in the current procedure. Other procedures may use the same variable names to create new variables. Use GLOBAL to declare variables common to all called procedures.
The variables may be of 4 types, depending on the symbol they end with:
Array variables have a number immediately following them in brackets which specifies the number of elements in the array. Array variables may be of any type, for example: x(6),y%(5),f$(5,12),z&(3)
When declaring string arrays, you must give two numbers in the brackets. The first declares the number of elements, the second declares their maximum length. For example surname$(5,8) declares five elements, each up to 8 characters long.
Variable names may be any combination of up to 32 numbers, alphabetic letters and the underscore character. They must start with a letter or an underscore. The length includes the %, & or $ sign, but not the () in string and array variables.
More than one GLOBAL or LOCAL statement may be used, but they must be on separate lines, immediately after the procedure name.
See also GLOBAL, CONST and Constants and variables — Storing values for later use.
Usage: LOCK ON
or LOCK OFF
Marks an application as locked or unlocked. When an app is locked with LOCK ON, the System screen will not send it events to change files or quit.
If, for example, you move to the task list or the document name in the System screen try to stop that running app by using the ‘Close file’ button or Ctrl+E, a message will appear, indicating that the app cannot close down at that moment.
You should use LOCK ON if your application uses a command, such as EDIT, MENU or DIALOG, which accesses the keyboard. You might also use it when the app is about to go busy for a considerable length of time, or at any other point where a clean exit is not possible. Do not forget to use LOCK OFF as soon as possible afterwards.
An application is initially unlocked.
Usage: a=LOG(x)
Returns the base 10 logarithm of x.
Use LN to find the base e (natural) log.
Usage: LOPEN device$
Opens the device to which LPRINTs are to be sent.
No LPRINTs can be sent until a device has been opened with LOPEN.
You can open any of these devices:
Only one device may be open at any one time. Use LCLOSE to close the device. LOPENned devices also close automatically when a program finishes running.
See also: Serial ports and printing.
Usage: b$=LOWER$(a$)
Converts any upper case characters in the string a$ to lower case and returns the completely lower case string.
E.g. if a$="CLARKE", LOWER$(a$) returns the string "clarke"
Use UPPER$ to convert a string to upper case.
Usage: LPRINT list of expressions
Prints a list of items, in the same way as PRINT, except that the data is sent to the device most recently opened with LOPEN.
The expressions may be quoted strings, variables, or the evaluated results of expressions. The punctuation of the LPRINT statement (commas, semicolons and new lines) determines the layout of the printed text, in the same way as PRINT statements.
If no device has been opened with LOPEN you will get an error.
See PRINT for displaying to the screen.
See LOPEN for opening a device for LPRINT.
See also Printer.opx — Printer and text handling for details of more advanced printing features.
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