Source on GitHub·lib/src/utils/fast_extension/

Overview

Import package:fast_package/fast_package.dart to use Dart extensions on String / nullable strings, nullable bool / int / double / num, and non-null num. APIs are getters or instance methods; they do not change the underlying types.

Extension	Receiver	Summary
FastStringExtension	String	camel / snake / kebab case, isValidUrl
FastStringNullSafeExtension	String?	empty defaults, optional default, non-null assert
FastBoolNullSafeExtension	bool?	default false / true, optional default
FastNumExtension	num	range check, divisibility
FastNumNullSafeExtension etc.	num? / int? / double?	zero defaults and nullSafeThrow

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String case

FastStringExtension splits on word boundaries (spaces, -, _, ., and camelCase breaks), then rejoins. Empty string → ''.

Examples

'hello_world'.toCamelCase;      // helloWorld
'user-name'.toPascalCase;       // UserName
'helloWorld'.toSnakeCase;       // HELLO_WORLD
'FirstName'.toSnakeCaseLower;   // first_name
'hello_world'.toKebabCase;      // hello-world

'https://example.com'.isValidUrl; // true

API reference

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toCamelCase / toPascalCase

Lower camelCase (first word lowercase) and PascalCase (each word capitalized).

	Type	Description
Return	String (getter)	Converted name; '' when isEmpty.

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toSnakeCase / toSnakeCaseLower

UPPER_SNAKE and lower_snake.

	Type	Description
Return	String (getter)	Words joined with _.

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toKebabCase

Lowercase kebab-case with -.

	Type	Description
Return	String (getter)	Words joined with -.

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isValidUrl

Rough URL check via built-in regex (optional http/https).

	Type	Description
Return	bool (getter)	true when matched.

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Nullable strings

FastStringNullSafeExtension on String?.

Examples

String? name;
name.nullSafeOrEmpty;           // ''
name.nullSafe(value: 'guest');  // guest
name.isNullOrEmpty;             // true

name.nullSafeThrow(); // throws ArgumentError when null (optional message / exception)

API reference

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nullSafeOrEmpty

	Type	Description
Return	String (getter)	null → ''.

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nullSafe

Parameter	Type	Required	Description
value	String?	no	Fallback when null; still empty → nullSafeOrEmpty.

Return	Type	Description
—	String	Use this when non-null; else value then empty fallback.

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nullSafeThrow

Parameter	Type	Required	Description
exception	Exception?	no	Custom exception; default ArgumentError.
message	String?	no	Default message when no exception.

Return	Type	Description
—	String	Returns self when non-null.

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isNullOrEmpty

	Type	Description
Return	bool (getter)	true for null or ''.

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Nullable booleans

FastBoolNullSafeExtension on bool?.

Examples

bool? flag;
flag.nullSafeOrFalse;  // false
flag.nullSafeOrTrue;   // true
flag.nullSafe(value: true); // true

API reference

API	Return	Description
nullSafeOrFalse	bool	null → false
nullSafeOrTrue	bool	null → true
nullSafe({bool? value})	bool	Fallback via value, then nullSafeOrFalse
nullSafeThrow({Exception? exception})	bool	Throw when null; else self

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Number utilities

FastNumExtension on num (non-null).

Examples

5.isBetween(1, 10);   // true (closed interval; argument order ignored)
10.isDivisibleBy(2);  // true
10.isDivisibleBy(0);  // false (divisor 0)

API reference

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isBetween

Parameter	Type	Required	Description
betweenOne	num	yes	One end of the interval
betweenTwo	num	yes	Other end

Return	Type	Description
—	bool	Whether this lies in the closed interval

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isDivisibleBy

Parameter	Type	Required	Description
divisor	num	yes	Divisor; 0 → false

Return	Type	Description
—	bool	Whether division is exact

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Nullable numbers

Separate extensions for int?, double?, and num? with the same shape; zero defaults are 0, 0.0, and 0.

Examples

int? count;
count.nullSafeOrEmpty;        // 0
count.nullSafe(value: 42);    // 42
count.nullSafeThrow();        // null → ArgumentError

double? rate;
rate.nullSafeOrEmpty;         // 0.0

API reference

Each type provides:

API	Description
nullSafeOrEmpty	Zero value when null
nullSafe({T? value})	Optional default, then zero fallback
nullSafeThrow({Exception? exception})	Non-null assert

Types: FastIntNullSafeExtension, FastDoubleNullSafeExtension, FastNumNullSafeExtension.