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Zingo Dictionary
Expression Evaluation

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Implicit Type Conversion

Some Lingo operations require that the operands be of a certain type. For example, you can add two integers, but you can not add and integer and a string together arithmetically.

Type Conversion for Numbers

In arithmetic operations, if both operands are integers, the result is an integer. If one or both of the expressions is a floating point number, the result is a float as well.

The following arithmetic operations all perform implicit type conversion on their operands.

+ (addition)
- (subtraction)
- (negation)
* (multiplication)
/ (division)
mod (modulo division (i.e. determine the remainder))

For example:

put 5 * 7
-- 35

put 5 * 7.0
-- 35.0

put 5.0 * 7
-- 35.0

put 5 + 7
-- 12

put 5 - 7.0
-- -2.0

put 5/7
-- 0

put 5.0/7
.707

put 7 mod 5
-- 2

put 5.0 mod 7
-- 5.0

Other mathematical functions

abs (expression)
returns a value that is the same type as the expression, with an integer or a float.

Type Conversion for Strings

Many Lingo commands operate on strings. If the initial operand is not a string, an error may result. Latter operands are often implicity converted to strings. The & and && concatenation operators, implicity convert numbers to strings.

For example:

set x = 7
put "The value of x is:"  && x
-- The value of x is 7

Explicit Type Conversion

You can force type conversions explicitly using the Lingo functions listed below.

string() - converts value to a string
value() - converts a string to a number, or a lis to a string
integer() - converts an float or string to an integer
float() - converts an integer or a string to a float
charToNum() - converts a character to it's ASCII code.
numToChar()- converts a ASCII code to its corresponding character.

Examples:

put string (x)

put value ("123")

put float (1)

put integer (7.5)

put charToNum ("A")

put numToChar (65)