EQU              Create equate                                      Directive

  name EQU expression

    name is assigned the result of evaluating expression. The name
    parameter must be a new symbol name that you haven't previously
    defined in a different manner.

    In MASM mode, EQU can generate any one of three kinds of equates:
                  1. a string equate (name represents a text string)
                  2. an alias equate (name represents another symbol)
                  3. a numeric equate (name represents a numeric value)

    In MASM mode, you can only redefine a symbol that you defined using
                  the EQU directive if you first define it as a string
                  equate.

    In Ideal mode, the EQU directive always defines a text macro (string
    equate).


    Text macros

    Syntax: name EQU text_string

    Text macros (string equates) are redefinable; you can redefine a text
    macro name in the same module to another text string.

    It is recommended that you enclose text_string in angle brackets when
    defining a text macro, e.g.

       copr EQU <'Copyright (c) '>

    because if you omit the brackets in MASM mode, Turbo Assembler will
    try to evaluate text_string to an expression, and an error may result.
    Only if it can't evaluate text_string will Turbo Assembler treat it as
    a text macro (to remain compatible with MASM). If you don't enclose
    text_string in brackets, and it's the name of another text macro, TASM
    will use that macro's contents. Otherwise, the macro will be defined
    to the text.

    In Ideal mode, EQU always defines a text macro.

    Text macro manipulation examples

        ideal                                   ; Enter Ideal mode
        abc     equ     <abc>                   ; abc = "abc"
        abc2    equ     abc                     ; abc2 = "abc"
        abc     equ     <def>                   ; abc = "def" (redefined)
        abc3    catstr  abc2,<,>,abc,<,>,abc2   ; abc3 = "abc,def,abc"
        abclen  sizestr abc                     ; abclen = 3
        abc3len sizestr abc3                    ; abc3len = 11
        comma1  instr   abc3,<,>                ; comma1 = 4
        comma2  instr   comma1+1,abc3,<,>       ; comma2 = 8
        abc4    substr  abc3,5                  ; abc4 = "def,abc"
        abc5    substr  abc3,5,3                ; abc5 = "def"
        abc6    equ     3+2+1                   ; abc6 = "3+2+1"
        abc7    equ     %3+2+1                  ; abc7 = "6"
        abc8    equ     %comma1                 ; abc8 = "4"