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SC_Assem.book Page 40 Thursday, September 23, 2004 10:44 AM
SC100 Assembler
Source Listing address of a DO loop, or any such location that must have a unique label, but is not significant for documenting the source file.
In a macro, however, the scope of local labels is the entire macro expansion, without regard to non-local labels. Accordingly, all local labels within a macro must be unique.
You can use such local labels freely within a macro definition, without regard to the number of macro expansions.
The assembler treats non-local labels within a macro expansion as normal labels. This means that such labels cannot occur more than once, unless you use them with the SET directive.
Strings
Literal ASCII strings can be operands for some assembler directives; they also have limited use in expressions. Such a string is one or more ASCII characters enclosed by single quotes ('). To specify an apostrophe within a literal string, use two consecutive apostrophe characters.
The alternate string delimiter is the double quote (") character. If you use double quotes to enclose a string, the assembler expands any DEFINE directive symbols contained in the string.
NOTE
Be careful about using the double-quote character inside macros, where this character is a dummy argument string operator. You can use the macro concatenation operator to escape a double-quoted string.
The concatenation operator (++) tells the assembler to consider two strings to be one. For example, the strings 'ABC'++'DEF' and 'ABCDEF' are identical to the assembler.
Use brackets ([ ]) to have the assembler extract a substring. For example, if the assembler encounters the expression ['abcdefg',1,3], it uses the string value 'bcd'.
Substrings are valid wherever strings are, and you can nest substrings.
The assembler includes functions for determining the length of a string, and the position of one string within another.
Source Listing
The source listing consists of the original source statements, formatted for easier reading, as well as other information the assembler generates. Most listing lines correspond directly to a source statement. Listing lines that do not correspond directly to source statements are page headings, error messages, expansions of macro calls, or expansions of directives such as DC.
40 SC100 Assembler User Guide
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