HLASM: V1R6 Language Ref

Model statementsEach field or subfield can consist of:v An ordinary character string composed of alphanumeric and special charactersv A variable symbol as a point of substitution, except in remarks fields andcomment statementsv Any combination of ordinary character strings and variable symbols to form aconcatenated stringThe statements generated from model statements during conditional assemblymust be valid machine or assembler instructions, but must not be conditionalassembly instructions. They must follow the coding rules described in “Rules formodel statement fields” on page 249 or they are flagged as errors at assembly time.Examples:LABEL L 3,AREALABEL2 L 3,20(4,5)&LABEL L 3,&AREAFIELD&A L 3,AREA&CVariable symbols as points of substitutionValues can be substituted for variable symbols that appear in the name, operation,and operand fields of model statements; thus, variable symbols represent points ofsubstitution. The three main types of variable symbol are:v Symbolic parameters (positional or keyword)v System variable symbols (see “System variable symbols” on page 259)v SET symbols (global-scope or local-scope SETA, SETB, or SETC symbols)Examples:&PARAM(3)&SYSLIST(1,3)&SYSLIST(2)&SETA(10)&SETC(15)Symbols That Can Be Subscripted: Symbolic parameters, SET symbols, and thesystem variable symbols &SYSLIST and &SYSMAC, can all be subscripted. Allremaining system variable symbols contain only one value.Listing of generated fieldsThe different fields in a macro-generated statement or a statement generated inopen code appear in the listing in the same column as they are coded in the modelstatement, with the following exceptions:246 HLASM: V1R6 Language Refv If the substituted value in the name or operation field is too large for the spaceavailable, the next field is moved to the right with one space separating thefields.v If the substituted value in the operand field causes the remarks field to bedisplaced, the remarks field is written on the next line, starting in the columnwhere it is coded in the model statement.v If the substituted value in the operation field of a macro-generated statementcontains leading spaces, the spaces are ignored.v If the substituted value in the operation field of a model statement in open codecontains leading spaces, the spaces are used to move the field to the right.v If the substituted value in the operand field contains leading spaces, the spacesare used to move the field to the right.v If the substituted value contains trailing spaces, the spaces are ignored.