docs reference

[[b]]

B

By Goblin Docs ~ 9 min read

b converts a value to a big number.

Overview

Use b when you want the shorter form of big:

price | "19.99".b
tax | "1.65".b
total | price + tax

:say(total)

price | "19.99".b
tax | "1.65".b
total | price + tax

:say(total)

value.b, b(value), value.big, and big(value) perform the same conversion.

The usual casting style places .b after the value:

price | "19.99".b
distance | 250.b

price | "19.99".b
distance | 250.b

The method form does not need parentheses.

The long name is available in the same style:

price | "19.99".big

price | "19.99".big

Use the free-call form when it reads more clearly around a larger expression:

price | b("19.99")

price | b("19.99")

b accepts integers, floats, percentages, and values that are already big numbers:

whole | 250.b
decimal | 12.5.b

whole | 250.b
decimal | 12.5.b

The result is a big number that can be used for high-precision decimal calculations.

When exact decimal values matter, converting from a string avoids carrying a float's binary representation into the result:

exact | "12.50".b

exact | "12.50".b

A numeric string may contain an optional sign and one decimal point:

"1250".b
"-42.75".b
"+8.5".b

"1250".b
"-42.75".b
"+8.5".b

Whitespace around the number is ignored:

"  19.99  ".b  /// same as "19.99".b

"  19.99  ".b  /// same as "19.99".b

Underscores are also ignored, so they may be used to make large values easier to read:

population | "1_250_000".b

population | "1_250_000".b

A string ending in % is not accepted. Use Pct for percent strings.

When given an array, b converts every value in the array:

prices | ["4.99", "12.50", "8.25"].b

prices | ["4.99", "12.50", "8.25"].b

When given a map, b converts every value and keeps the keys unchanged:

costs | {
    food: "24.50",
    travel: "80.00"
}.b

costs | {
    food: "24.50",
    travel: "80.00"
}.b

Every value inside the collection must be convertible to a big number.

b is an alias for big:

short_method | "123.45".b
long_method | "123.45".big
short_call | b("123.45")
long_call | big("123.45")

short_method | "123.45".b
long_method | "123.45".big
short_call | b("123.45")
long_call | big("123.45")

Choose the form that reads best in your program. See Big for the primary builtin page.

value.b
b(value)

value.b
b(value)

The equivalent long forms are value.big and big(value).

Argument	Type	Description
`value`	value	A number, numeric string, array, or map to convert.

.b returns a big number, or a collection whose values have been converted to big numbers.

b requires exactly one argument:

b()
/// error: R0301 wrong-arity

b()
/// error: R0301 wrong-arity

The value must be convertible to a big number:

b(true)
/// error: R0215 type-lock-cast

b(true)
/// error: R0215 type-lock-cast

A string must contain a valid decimal number:

b("twelve")
/// error: R0215 type-lock-cast

b("twelve")
/// error: R0215 type-lock-cast

Percent strings must be converted with pct instead:

b("12.5%")
/// error: R0215 type-lock-cast

b("12.5%")
/// error: R0215 type-lock-cast