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Chapter 5 - Text Utilities / Text Utilities Reference

Routines / Converting Between Strings and Floating-Point Numbers

StringToExtended

The StringToExtended function converts a string representation of a number into a floating-point number.

FUNCTION StringToExtended(source: Str255;
                          myFormatRec: NumFormatStringRec;
                          partsTable: NumberParts;
                          VAR x: Extended80): FormatStatus;

source

A Pascal string that contains the string representation of a number.

myFormatRec

The internal representation of the formatting information for numbers, as produced by the StringToFormatRec function.

partsTable

A record obtained from the tokens ('itl4') resource that shows the correspondence between generic number part separators (tokens) and their localized version (for example, a thousand separator is a comma in the United States and a decimal point in France).

x

On output, contains the 80-bit SANE representation of the
floating-point number.

DESCRIPTION

StringToExtended uses the internal representation of number formatting information that was created by a prior call to StringToFormatRec to parse the input number string. It uses the number parts table to determine the components of the number string that is being converted. StringToExtended parses the string and then converts the string to a simple form, stripping nondigits and replacing the decimal point before converting it into a floating-point number. If the input string does not match any of the patterns, then StringToExtended parses the string as well as it can and returns a confidence level result that indicates the parsing difficulties.

StringToFormatRec returns a value of type FormatStatus that denotes the confidence level for the conversion that it performed. The low byte of the FormatStatus value is of type FormatResultType, the values of which are described in Table 5-6 on page 5-38.

IMPORTANT

Be sure to cast the result of StringToExtended to a type FormatResultType before working with it.

SPECIAL CONSIDERATIONS

StringToExtended returns an 80-bit, not a 96-bit, representation.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the StringToExtended function are

Trap macro	Selector
_ScriptUtil	$8210 FFE6

SEE ALSO

For comprehensive details on the number parts table, see the description of the tokens ('itl4') resource in the appendix "International Resources" in this book.

To obtain a handle to the number parts table from a tokens resource, use the GetIntlResourceTable procedure, which is described in the chapter "Script Manager" in this book.