#Definitin of indirection quotation plus#

Null Subscripts and Collation ¶ Null Subscripts ¶ For complete information on enabling this functionality, See Chapter 12: “Internationalization”. YottaDB allows definition of alternative collation sequences. In addition, YottaDB allows the empty string subscript in most contexts (the null, or empty, string collates ahead of all canonic numeric subscripts). String subscripts collate in ASCII sequence. Numeric subscripts collate from negative to positive in value order. M collates all canonic numeric subscripts ahead of all string subscripts, including strings such as those with leading zeros that represent non-canonic numbers. Utility program, and global variables that start withĪpplications should not use them. The format for an M global or local variable is:Īs global variables that start with ^%Y are used by the

M array subscripts are expressions, and are not restricted to numeric values. These arrays generally serve logical, rather than mathematical, purposes. Sparse arrays comprise existing subscripts and data nodes - no space is reserved for potential data nodes. In M, subscripted variables identify elements in sparse arrays. Any variable may be unsubscripted or subscripted.

M does not require predefinition of variable type or size. Source and object file names (not including the extension)Ī trigger name is up to 28 characters and a replication instance name is up to 15 characters. YottaDB’s limit of 31 characters applies to: However, the portability section of the standard recommends limiting names to a maximum of eight (8) characters. M does not restrict the length of names in the main body of the standard. That is, M treats ABC, Abc, ABc, AbC ABC, and abc as six different names. Therefore, M permits a variable or a label called SET even though the language has a command called SET. That is, M always distinguishes keywords by context. By convention, names starting with percent signs are generally application-independent or distinguished in some similar way. The percent sign can only appear as the first character in a name. M names are alphanumeric and must start with an alphabetic character or a percent sign (%). M uses names for variables, LOCK command arguments, labels on lines, and routine names. The sign and/or decimal have no affect on the evaluation of a truth-valued expression. In other words, M treats expressions that have a non-zero numeric value as true, and expressions that have a zero numeric value as false. However, it stops the evaluation and returns a true value (1) as soon as it encounters a non-zero digit, otherwise it returns a false value (0). When M syntax specifies a tvexpr, M evaluates the data as a numeric. When M syntax specifies an intexpr, M evaluates the data as it would a numexpr except that it stops the evaluation at any decimal point including the first. Numbers with three digits or fewer to the right of the decimal point are precise. YottaDB provides 18 digits of accuracy, independent of the decimal point (.) placement, and a numeric range from 10**(-43) to (10**47). The first decimal point (.) in the string

#Definitin of indirection quotation plus#

M stops the evaluation and provides the result generated from successfully evaluated characters when it encounters any character that is not the following:Ī plus sign (+) or minus sign (-) and also the first character in the string When M syntax specifies a numexpr, M evaluates the data as a sequence of ASCII characters that specify a number.

However, M evaluates data using methods that vary according to context. M operates with a single basic data type, string. This section describes the features of the language that are not covered in the Commands, Functions, or Intrinsic Special Variables chapters. M is a general purpose language with an embedded database system. This chapter contains information about exceptions, as well as information about general M features. Commands, Functions, and Intrinsic Special Variables are each described in separate chapters. This chapter describes general features of the M language, as well as general information about the operation of YottaDB. Optional YottaDB Environment Translation Facility Global Variables and Resource Name Environments