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==Parts Of A Business Rules Statement==

===Statements===

A typical [[Business Rules!]] statement consists of the following:
#A [[line number]].
#A [[line Label (program)|line label]] (optional).
#A primary keyword or its [[abbreviation]]. 
#One or more secondary keywords or phrases along with their associated values (sometimes optional).
#One or more "error condition line-ref" conditions (optional).
#Remark or [[comment]] (optional).

"Optional" items may be included but are not required.

Notice that the listed elements refer to a typical statement. Some statements consist mainly of a primary keyword [[RETURN]] or [[RETRY]] for instance, only the line number and optional programmer's remarks or a line label are permitted with these two statements. See the syntax diagrams for individual [[Statements]] for specific details.

====Analysis of an Example Statement====

The following formatted Print statement will be used to describe the components of a statement:

 00020 BIG: PRINT USING F1: A$,T(5) CONV 00520 ! comments

{|
|-valign="top"
|width="10%"|'''00120'''||is a line number.
|-valign="top"
|width="10%"|'''BIG'''||is a line label.
|-valign="top"
|width="10%"|'''PRINT'''||is a primary keyword. Primary keywords specify the type of operation that you wish to perform.
|-valign="top"
|width="10%"|'''USING F1'''||is a secondary phrase. This phrase consists of the secondary keyword USING and the line reference F1 (a line label). Secondary keywords and secondary phrases add detail to the instructions in the statement.
|-valign="top"
|width="10%"|'''A$ and T(5)'''||are references to [[Variable|variables]].
|-valign="top"
|width="10%"|'''CONV 520'''||is an "error-cond line-ref" specification. It transfers control of the program to line 00520 if a CONV error occurs during execution of line 00120.
|-valign="top"
|width="10%"|'''! comments'''||is an optional comment that follows the statement. An exclamation point signals the start of this remark; any comment the programmer wishes to make may follow. Note that certain statement keywords, for example, [[DATA]], do not allow for comments on the same line, in which case comments must be placed on an adjacent line alone.
|-valign="top"
|}

Each command in a '''procedure file''' may be followed by at least one space, an exclamation point (!) and a comment. Business Rules will ignore everything after the exclamation point.

Remarks may also reside on their own line in a procedure file, as follows:

 LOAD MENU.BR
 ! Load the program MENU.BR
 RUN


====Line numbers====
{{:Line number}}

====Line labels - Program files====
{{:Line Label (program)}}

====Line labels -  Procedure Files====
{{:Line Label (procedure)}}

====Line Continuation====

{{:Line Continuation}}

====Comments====

{{:Comment}}

====Uppercase VS Lowercase Letters====
Throughout this reference material, uppercase letters are generally used to denote the names of commands, statements, functions and other specifications. Uppercase is also used with the names of most files or programs except where the file or program being referred to is exclusively used with the Unix or Linux operating system. Regardless of your operating system, Business Rules accepts both uppercase and lowercase letters as identical except when they are used in a literal string. It defaults to displaying all but literal strings in uppercase (see the BRConfig.sys [[STYLE]] specification to change this default).

==Syntax Explanation==
{{:Syntax Explanation}}

==Syntax Diagrams and Special Considerations==

Diagrams are used throughout this wiki to explain the syntax of Business Rules commands, statements, and various other syntactical specifications. This section explains how to read the conventions used in the diagrams. For more details, see [[diagram conventions]].

Syntax diagrams provide a road map through a command or statement's syntax. Syntax diagrams always follow a logical pattern from left to right. If they require you to pass through a particular parameter, then that parameter is required. If they allow you to bypass a particular parameter, then that parameter is optional. If they allow you to return to the left, that parameter can be repeated multiple times, separated by a delimiter each time. 

Although all syntax diagrams (whether for a command, statement or other specification) must be read the same way, the actual specification you are working with may be subject to other requirements or options as well. A statement, for example, must always have a line number. Continue reading for more about these requirements and options.

===Parameter Explanations===
====Array Name====
The "array-name" parameter is a name representing either a numeric or a string [[array]]. For rules regarding these names, see [[Variable]].

====Baud====
{{:Baud}}

====Border=Spec====
The "BORDER=spec" parameter represents an insertable syntax which is used in the OPEN window statement to identify a border type for the window being opened. See the [[Border Spec| BORDER=spec]] for additional information and the syntax diagram.

====Bufsize====
The [[BUFSIZE]] parameter specifies the size of the buffer for DOS versions of Business Rules. The default is 2000 bytes, which is low for high-speed data transmission. To avoid losing data with rates of 2400 bps or higher; an increased BUFSIZE is recommended.

In Business Rules, Unix and Linux versions ignore the BUFSIZE parameter, as the operating systems handle the buffering for these versions instead.

====Col====
{{:Col}}

====Concatenation====
Concatenation is the joining of two or more strings. In Business Rules, the ampersand (&) is the concatenation operator. Concatenation may be used in any output or assignment statement to join any number of string expressions.

See [[Concatenation]] for examples.

====Corners====
{{:Corners}}

====Drive====
{{:Drive}}

====Drive Num====
"Drive-num" is a digit which indicates a System/23 drive; Business Rules translates it into a DOS drive letter. This parameter may not be specified with a redirection symbol (>) or when a drive letter is specified.

====Error-Cond Line-Ref====
{{:Error-Cond Line-Ref}}

====Field Length====
"Field-length" is an integer value, which identifies the number of columns in the specified field. This parameter is required as a part of any numeric format specification except PIC.

====Field Spec====
"Field-spec" represents an insertable syntax that is used to provide field definitions for the full screen processing statements. See [[Field Specs]].

====Filenames====
"Filename" is a name consisting of alphabetic, numeric or underscore characters and an optional period and extension of up to three consecutive letters. [[Wildcard characters]] (* and ?) may be used in file names specified with the COPY, DIR, DROP, and FREE commands. (Prior to Version 3.9, filenames were limited to eight characters) Unix defaulted to case sensitive and DOS/Windows defaulted to case insensitive. Business Rules! defaults to lower case on all platforms, unless overridden by a FILENAMES configuration statement in BRconfig.sys.

This new BRCONFIG.SYS statement controls the appearance of newly created files:
 FILENAMES    UPPER_CASE | LOWER_CASE | MIXED_CASE [SEARCH]

The file name requirements for all types of files are identical. However, one item to be aware of is that procedure files which use an extension of .$$$ will automatically delete themselves after closing. See [[Proc]] for additional information.

====File Num====
"File-num" is a numeric expression or an integer from zero to 999 and is always immediately preceded by a pound symbol (#). A file number matches a logical file to a physical file or device. File numbers are defined in [[OPEN]] statements, then used in I/O statements for that file or device.

Two special file numbers which do not require [[OPEN]] statements are 0 (for input or output to the main BR screen) and 255 (for output to the printer).

No file numbers are required when INPUT, LINPUT, RINPUT, or PRINT are used for I/O from the keyboard or to the display screen. 

====>file-ref====
The ">file-ref" (not to be confused with just "[[File Ref|file-ref]]" which only names the file to be used) parameter causes all information which would normally be printed on the screen to be sent to the file specified in the file-ref (see the "file-ref" description for information about the correct syntax). One special case is the RUN command in which ">file-ref" redirects printer output to a file. Wherever ">file-ref" or ">>file-ref" (with two redirection arrows) may also be specified.

Using one redirection arrow causes the screen information to write directly over any contents that currently exist in the specified file.  Using two redirection arrows cause the information that would normally go to the screen to be appended to the end of the specified file. The TYPE command with the >>file-ref parameter may thus be used to append a display file to another file. Likewise, the LIST command may be used with >>file-ref to append the contents of a program to another program which has been saved in source.

(Be careful about line numbers when using this technique, as line numbers that are duplicated in the same file will replace one another upon loading from source.)

====Fixed point numbers====
Fixed-point numbers are numbers with a decimal point in a fixed position.

"Floating point form-spec" represents a format specification from the following group: D, S, or L. These format specifications are fast, but non-portable. See [[File I/O]] for more information.

Floating-point numbers are numbers which allow the decimal point to "float" to any position. The Business Rules syntax is nEm, where n is a numeric constant indicating the sign and significant digits in the number, E represents base 10, and m is a signed integer representing the power to which 10 is raised.

The largest and smallest numbers available to the system vary according to the hardware and operating system being used. The system function INF can be used to print the largest possible number on any given system; 1/INF generates the smallest number. For all DOS, Unix and Linux versions available at the time of writing, the largest number is 1.000E+307; similarly, the smallest number is 1.000E-307. Some caution should be used in working with numbers near these extremes (e.g., using exponential notation in SORT). Also, for any given combination of hardware and Business Rules, the system infinity function INF and some testing should be combined to determine whether or not intermediate values used in calculations will be truncated.

====Fraction Length====
The "fraction-length" parameter is an integer value that identifies the number of digits contained in the fractional portion of the item to be printed or input. This integer must be preceded by a decimal point.

====Window Number====
"Wind-num" is the number of a window file that has been opened by an OPEN window statement. It must be a numeric expression or integer value that equals a value between 1 to 999. No other open file or open window may use the same value. Open windows do not count against the operating system limit on open files.

====Wildcard Characters====
{{:Wildcard characters}}

====Variable Name====
A "var-name" or "Variable Name" may be either numeric or string. It may be a subscripted or un-subscripted variable, or an array name preceded by MAT. Var-name items are used mainly in various types of input statements to assign values to variables. They typically occur in lists separated by commas.

====Form-Spec====
The "string form-spec" parameter should be replaced with a string format specification from the following group: C, CC, CR, CL, CU, G, GL, GU, V, VL, VU. The specifications that are applicable for a given statement are identified in the parameters text for that statement. See [[Format specifications]] for details.

The CL, CU, GL, GU, VL, and VU specifications are valid only in full screen processing statements (PRINT FIELDS, INPUT FIELDS, and RINPUT FIELD); they cannot be used in either type of FORM statement.

====String Expression====
{{:string expression}}

====Helpstring====
The "helpstring" parameter represents an insertable syntax, which is used in the full screen processing statements to specify the user level, window placement and text for field help windows. For additional information and the "helpstring" diagram, see [[Field Help]].

====Increment====
The "increment" parameter is used in the AUTO ATT and RENUM commands. It represents an integer value, which indicates how much the system should increase the numbers from one line number to the next.

====Input====
The "INPUT" keyword identifies that the file is to be opened so that its data may only be used as input for the program.

====Int and Integer====
The "int" parameter represents an unsigned, positive, non-zero whole number.

The "integer" parameter represents a whole number (no decimal points or fractions allowed). NOTE the difference between "integer" and "int".

====Internal Form Spec====
{{:Internal form spec}}

====Key Length====
The "key-length" parameter should be replaced with a number that identifies the number of characters (or columns) in the key.

====Key Start Position====
"Key start-pos" indicates the record position of the first key character for the index.

====Length====
"Length" is an integer value that sets the maximum length of all elements in the string variable or array.

====Line Label====
A line label is an optional name for a program line that is specified immediately after the line number. See [[Line Label (program)]] or [[Line Label (procedure)]].

====Line Num====
The "line-num" parameter indicates that you must specify a line number rather than a line label. Line numbers can be used only in programs (not in procedure files) and must be integers from 1 to 99999.

====Line Ref====
{{:line ref}}

====Numeric Array====
"Num-array" indicates that a numeric array name should be specified.

====Numeric Constant====
{{:Numeric constant}}

====Numeric Expression====
{{:numeric expression}}

====Numeric Variable====
{{:Numeric Variable}}

====Num Form Spec====
The "num form-spec" parameter should be replaced with a numeric format specification from the following group: G, GZ, N, or NZ. The specifications, which are applicable for a given statement, are identified in the parameters text for that statement. See [[File I/O]] chapter for information about individual format specifications.

====Outin====
The "OUTIN" keyword indicates that the file is to be opened so that information may move in two directions: both into and out of the data file.

====Output====
{{:OutPut}}

====Parity====
"PARITY=spec" is an OPEN communications parameter. The "PARITY" keyword and equal symbol (=) must be followed by one of three replacements for "spec": N (no parity checking), E (even parity) or O (odd parity).

====Path====
The "path" parameter identifies the sequence of directories to be used. Each directory must be separated by a backslash "\\".  When the path does not begin with a backslash, searching begins at the default directory.

====PIC====
{{:PIC}}

====Row====
{{:Row}}

====String Array====
"String-array" indicates that a string array name should be specified. For rules regarding these names, see "string variable".

====String Constant====
{{:String Constant}}

===Quote Processing===
Quotation marks suppress the recognition of separators in accordance with the following rules.

;Standard BR Quote Processing

When examining str$ left to right, the first character (and the first character after each separator) is checked to see if is either (') or ("). If it is ether of those then it activates quotation processing which suppresses the recognition of separators until quotation processing is deactivated. The first character thus becomes the governing quote type until quotation processing is deactivated.

The string is copied until it ends or until an odd number of successive occurrences of the governing quote type is encountered. During this processing, two adjacent occurrences of the governing quote character denote an embedded occurrence of the quote character.
Examples:
{|
|"abc,def" -> ||abc,def   || where the comma is not recognized as a separator and is part of the data.
|-
|abc"def -> ||abc"def   || naturally embedded quotes may occur anywhere within a string after the first character
|-
|"abc"def" -> ||abcdef"  || quotation processing is deactivated by the center quote mark
|-
|"abcdef" -> || abcdef  || normal data
|-
|"abc'def" -> || abc'def  || the single quote is treated like any other character while double quotes govern
|-
|'abc"def' -> || abc"def ||  double quotes are treated like any other character while single quotes govern
|-
|"abc""def" -> || abc"def || pairs of governing quotes denote a single embedded quote
|-
|"abc"""def" -> || abc"def"  || the third successive occurence deactivates quote processing
|}

===MAT2STR===
 MAT2STR( MAT zzz$, str$ [, sep$ [, flags$]] )

Where '''flag$''' is in the format:
 [ quote-type ] [ :LTRM ] | [ :TRIM ] | [ :RTRM ]
Where '''quote-type''' can be Q, QUOTES, ('), or ("), case insensitive. Quote-type denotes that each element should be enclosed in quotation marks. The trim flags denote pre-processing of array elements and the leading colon is only present when quote-type is specified.

If Q or QUOTES is specified the BR automatically determines which quote type to apply as follows:

The element is scanned left to right for either type of quote character. If a quote character is encountered, then only the next character is examined. If two occurrences of the same quote character are encountered then that character is used to enclose the element. However, if a single occurrence of a quote character is encountered then the element is enclosed in the alternate quote type. If no quote character is encountered then double quotes are applied.
Examples:
;Quote Type is Q or QUOTES
{|
|abcdef -> ||"abcdef"
|-
|abc'def -> ||"abc'def"
|-
|abc"def -> ||'abc"def'
|-
|abc""def -> ||"abc""def"
|-
|'abcdef -> || "'abcdef"
|}

;Quote Type is ' (single)
{|
|abcdef ->|| 'abcdef'||...
|-
|'abcdef -> ||'''abcdef'  || single quotes get doubled when embedded in singles quotes
|-
|"abcdef -> || '"abcdef' ||  leading double quote is treated normally
|}

;Double quotes are the same as single
When using MAT2STR on a 2 dimensional array, the first delimiter is used for individual elements and the second delimiter at the end of each row. This principle also applies to three to seven dimensions.
Example
Given the following two dimensional array zzz$ containing the values-
{|
|    1 ||           2
|-
|    3   ||         4
|}

The following statements-
    10 Sep$(1)=","
    20 Sep$(2)=hex$("0D0A") ! CRLF
    30 MAT2STR( MAT zzz$, str$, MAT Sep$ )
    40 PRINT str$

Will produce-
    1,2
    3,4


[[Category:Statements]]
[[Category:Basics]]