6.1 Expression syntax

An expression applies relational operators to simple expressions. Simple expressions are a series of terms (what a term is, is explained below), joined by adding operators.

_________________________________________________________________________________________________________ Expressions
-- expression -simple expression---------------------------------------
- * -|simple expression
--<>=-|
- >=-|
--= -|
- <>-|
| in-|
- is-

-- simple expression -|-term ------------------------------------------
|--+ ---|
-----|
|or -|
-xor--
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The following are valid expressions:

 GraphResult<>grError
 (DoItToday=Yes) and (DoItTomorrow=No);
 Day in Weekend

And here are some simple expressions:

 A + B
 -Pi
 ToBe or NotToBe

Terms consist of factors, connected by multiplication operators.

_________________________________________________________________________________________________________ Terms
-- term ---factor--------------------------------------------------
---- *----|
-- /--|
|div--|
|mod -|
|and -|
|shl--|
|shr--|
--as--
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Here are some valid terms:

 2 * Pi
 A Div B
 (DoItToday=Yes) and (DoItTomorrow=No);

Factors are all other constructions:

_________________________________________________________________________________________________________ Factors
-- factor---( -expression- )-----------------------------------------
- variable reference -|
---function call---|
|unsigned constant|
|--not -factor---|
|--sign -factor---|
|-set constructor-|
|--value typecast--|
---address factor ---

-- unsigned constant--|-unsigned number --------------------------------
|-character string-|
|constant identifier|
-------Nil-------
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