TAL Reference Manual

TAL Reference Manual—526371-001
4-1
4 Expressions
This section describes the syntax for:
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Arithmetic and conditional expressions
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Special expressions (assignment, CASE, IF, group comparison)
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Bit operations (extraction and shift)
Section 5, “Using Expressions,” in the
TAL Programmer’s Guide describes:
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Assigning conditional expressions
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Dereferencing simple variables (formerly called temporary pointers)
About Expressions
An expression is a sequence of operands and operators that, when evaluated,
produces a single value. Operands in an expression include variables, constants, and
function identifiers. Operators in an expression perform arithmetic or conditional
operations on the operands.
Expressions, for example, can appear in:
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LITERAL declarations
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Variable initializations and assignments
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Array and structure bounds
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Indexes to variables
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Conditional program execution
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Parameters to procedures or subprocedures
The compiler at times requires arithmetic or conditional expressions. Where indicated
in this manual, specify one of the following kinds of expressions: