Expr

Expr<S, T> is an expression over the signals of S that evaluates to a T in the browser.

Building expressions

+, -, *, and % work on i32, i64, and f64, / on f64, and ! on bool.

Item	Summary
`Expr::lit`	A constant value, serialized to JSON once at render time.
`if_else`	The expression `then` while `cond` is true, and `otherwise` while it is false.
`Expr::now`	The browser's current time, in milliseconds since the Unix epoch.
`Expr::random_below`	A random integer from 0 up to but not including `bound`, drawn in the browser.
`at`	The field `field` of the struct this expression evaluates to.
`with`	A copy of this struct with `field` replaced by `value`.
`let_in`	The expression `body` builds from this value, which is evaluated once however often `body` uses it.
`let_in_stmt`	A statement that runs `body` with this value, computed once when the statement runs.

Comparisons and logic

Item	Summary
`equals`	Whether this value equals `rhs`.
`not_equals`	Whether this value differs from `rhs`, comparing JSON forms.
`gt`	Whether this value is strictly greater than `rhs`.
`ge`	Whether this value is greater than or equal to `rhs`.
`lt`	Whether this value is strictly less than `rhs`.
`le`	Whether this value is less than or equal to `rhs`.
`and`	Whether both this value and `rhs` are true.
`or`	Whether this value or `rhs` is true.

Numbers and text

Item	Summary
`min`	The smaller of this value and `rhs`.
`max`	The larger of this value and `rhs`.
`to_f64`	This number as an `f64`, which holds every `i32` exactly.
`to_fixed`	This number as text with `digits` digits after the point.
`floor`	The largest whole number at or below this one.
`ceil`	The smallest whole number at or above this one.
`round`	The nearest whole number, with a halfway value rounded up.
`log10`	The base 10 logarithm of this number.
`pow`	This number raised to the power `exponent`.
`format`	This number as text in `format`, with its digits grouped and its affixes.
`NumberFormat`	How `format` writes a number: decimals, separators, and affixes.
`plural`	The form that `form` gives for the plural category of this number in `locale`.
`PluralCategory`	A plural category of the Unicode CLDR, which `Intl.PluralRules` picks for a number.
`IntlLocale`	A locale that the browser's `Intl` writes text for, and the first HTML matches.
`Timestamp`	A point in time, in milliseconds since the Unix epoch.
`format_date`	This time written in `format` with the browser's `Intl.DateTimeFormat`.
`DateFormat`	How `format_date` writes a `Timestamp`: a locale, styles, and a time zone.
`relative_to`	This time relative to `now` in `locale`, such as `3 minutes ago`.
`to_text`	This value as display text, as JavaScript's `String` writes it.
`label`	The text `label` gives for this value's variant, with every variant covered.
`Variants`	An enum with `#[derive(Segment)]`, whose variants the derive lists.
`concat`	This string with `rhs` appended.
`trim`	This string without leading and trailing whitespace.
`to_lowercase`	This string in lowercase.
`to_uppercase`	This string in uppercase.
`contains`	Whether `needle` occurs in this string.
`starts_with`	Whether this string starts with `prefix`.
`char_count`	The number of Unicode scalar values, as Rust's `chars().count()`.
`all_chars`	Whether every character of this string is in `class`, true for an empty string.
`any_char`	Whether some character of this string is in `class`, false for an empty string.
`CharClass`	A set of ASCII characters that `all_chars` and `any_char` test for.

Lists and options

Item	Summary
`len`	The number of items.
`nth`	The item at `index`, or `None` past either end.
`is_some`	Whether this option holds a value.
`is_none`	Whether this option is `None`.
`unwrap_or`	The held value, or `default` for `None`.
`some`	This value wrapped in `Some`.