mirror of
https://github.com/sass/sass.git
synced 2024-09-21 02:27:30 +00:00
Natalie Weizenbaum
parent
bfbb8e91ea
commit
bb187794a0
@ -172,7 +172,7 @@ A number has *known units* unless it has unit `%`.
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Replace [the definition of `Potentially Slash-Separated Number`] with the
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following:
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[the definition of `Potentially Slash-Separated Number`]: ../spec/types/number.md#potentially-slash-separated-number
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[the definition of `Potentially Slash-Separated Number`]: slash-separator.md#existing-behavior
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A Sass number may be *potentially slash-separated*. If it is, it is associated
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with two additional Sass numbers, the *original numerator* and the *original
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@ -325,7 +325,7 @@ numbers.
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Add `CalcExpression`s, `ClampExpression`s, `CssMinMax`es to the list of operands
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of the `/` operator that can create a [potentially slash-separated number].
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[potentially slash-separated number]: ../spec/types/number.md#potentially-slash-separated-number
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[potentially slash-separated number]: slash-separator.md#existing-behavior
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## Syntax
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@ -447,24 +447,54 @@ This function is also available as a global function named `hue()`.
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hwb($channels)
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```
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* If `$channels` is not an unbracketed space-separated list, throw an error.
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* If `$channels` is an unbracketed slash-separated list:
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* If `$channels` does not includes exactly three elements, throw an error.
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* If `$channels` doesn't have exactly two elements, throw an error.
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Otherwise, let `hwb` be the first element and `alpha` the second element.
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* Let `hue` and `whiteness` be the first two elements of `$channels`
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* If either `hwb` or `alpha` is a [special variable string], return a plain
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CSS function string with the name `"hwb"` and the argument `$channels`.
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* If the third element of `$channels` has preserved its status as
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two slash-separated numbers:
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* If `hwb` is not an unbracketed space-separated list, throw an error.
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* Let `blackness` be the number before the slash and `alpha` the number
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after the slash.
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* If the first element of `hwb` is an unquoted string which is
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case-insensitively equal to `from`, return a plain CSS function string
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with the name `"hwb"` and the argument `$channels`.
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* Otherwise:
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* If `hwb` has more than three elements, throw an error.
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* Let `blackness` be the third element of `$channels`.
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* If `hwb` has fewer than three elements:
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* Call `hwb()` with `hue`, `whiteness`, `blackness`, and `alpha` (if it's
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defined) as arguments and return the result.
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* If any element of `hwb` is a special variable string, return a plain
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CSS function string with the name `"hwb"` and the argument `$channels`.
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* Otherwise, throw an error.
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* Let `hue`, `whiteness`, and `blackness` be the three elements of `hwb`.
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* Call `hwb()` with `hue`, `whiteness`, `blackness`, and `alpha` as
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arguments and return the result.
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* Otherwise, If `$channels` is not an unbracketed space-separated list, throw an error.
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* If `$channels` does not includes exactly three elements, throw an error.
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* Let `hue` and `whiteness` be the first two elements of `$channels`
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* If the third element of `$channels` has preserved its status as
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two slash-separated numbers:
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* Let `blackness` be the number before the slash and `alpha` the number
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after the slash.
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* Otherwise:
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* Let `blackness` be the third element of `$channels`.
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* Call `hwb()` with `hue`, `whiteness`, `blackness`, and `alpha` (if it's
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defined) as arguments and return the result.
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[special variable string]: ../functions.md#special-variable-string
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### `ie-hex-str()`
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@ -72,6 +72,7 @@ This function is also available as a global function named `list-separator()`.
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slash($elements...)
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```
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* Emit a deprecation warning.
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* If `$elements` contains zero or one values, throw an error.
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* Return an unbracketed slash-separated list containing `$elements`.
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@ -291,7 +291,8 @@ plain CSS function named `"rgb"` that function is named `"rgba"` instead.
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* Call `rgb()` with `red`, `green`, `blue`, and `alpha` as arguments and
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return the result.
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* If `$channels` is not an unbracketed space-separated list, throw an error.
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* Otherwise, if `$channels` is not an unbracketed space-separated list, throw
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an error.
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* If the first element of `$channels` is an unquoted string which is
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case-insensitively equal to `from`, return a plain CSS function string
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@ -425,7 +426,8 @@ plain CSS function named `"hsl"` that function is named `"hsla"` instead.
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* Call `hsl()` with `hue`, `saturation`, `lightness`, and `alpha` as
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arguments and return the result.
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* If `$channels` is not an unbracketed space-separated list, throw an error.
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* Otherwise, if `$channels` is not an unbracketed space-separated list, throw
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an error.
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* If the first element of `$channels` is an unquoted string which is
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case-insensitively equal to `from`, return a plain CSS function string
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@ -5,12 +5,13 @@
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* [Definitions](#definitions)
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* [Source File](#source-file)
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* [Vendor Prefix](#vendor-prefix)
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* [Grammar](#grammar)
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* [Syntax](#syntax-1)
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* [`InterpolatedIdentifier`](#interpolatedidentifier)
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* [`InterpolatedUrl`](#interpolatedurl)
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* [`Name`](#name)
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* [`SpecialFunctionExpression`](#specialfunctionexpression)
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* [`PseudoSelector`](#pseudoselector)
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* [`ProductExpression`](#productexpression)
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* [Procedures](#procedures)
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* [Parsing Text](#parsing-text)
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* [Parsing Text as CSS](#parsing-text-as-css)
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@ -38,7 +39,23 @@ points followed by another U+002D. An identifier only has a vendor prefix if the
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final U+002D is followed by additional text. This additional text is referred to
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as the *unprefixed identifier*.
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## Grammar
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## Syntax
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Unless otherwise specified, if a grammar production's value is parsed as a
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single other named Sass production, then the AST does not contain a
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representation of the intermediate production.
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> For example, suppose we have the productions:
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>
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> <x><pre>
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> **Foo** ::= Bar '*'?
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> **Bar** ::= \<ident-token>
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> </pre></x>
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>
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> Parsing `"ident*"` creates an AST that contains a `Foo` that contains a `Bar`.
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> But parsing `"ident"` alone creates an AST that only contains a `Bar`—the
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> `Foo` wrapper is removed. (The `Bar` wrapper is *not* removed because
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> `<ident-token>` is a CSS production, not a Sass production.)
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### `InterpolatedIdentifier`
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@ -121,6 +138,12 @@ followed by a parenthesis, it must be parsed as a `SelectorPseudo` or an
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No whitespace is allowed anywhere in a `PseudoSelector` except within
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parentheses.
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### `ProductExpression`
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<x><pre>
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**ProductExpression** ::= (ProductExpression ('*' | '%'))? UnaryPlusExpression
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</pre></x>
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## Procedures
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### Parsing Text
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@ -219,7 +242,6 @@ modifications. The following productions should produce errors:
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* All SassScript operations *except for*:
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* `/`
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* `not`
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* `or`
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* `and`
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@ -249,11 +271,6 @@ SCSS:
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* The tokens `not`, `or`, `and`, and `null` should be parsed as unquoted
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strings.
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> The `/` operation should be parsed as normal. Because variables,
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> parentheses, functions that return numbers, and all other arithmetic
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> expressions are disallowed, it will always compile to slash-separated values
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> rather than performing division.
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### Consuming an Identifier
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This algorithm consumes input from a stream of [code points][] and returns a
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@ -13,12 +13,14 @@
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* [`Number`](#number)
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* [Procedures](#procedures)
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* [Evaluating a `FunctionCall` as a Calculation](#evaluating-a-functioncall-as-a-calculation)
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* [Adjusting Slash Precedence](#adjusting-slash-precedence)
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* [Evaluating an Expression as a Calculation Value](#evaluating-an-expression-as-a-calculation-value)
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* [Simplifying a Calculation](#simplifying-a-calculation)
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* [Simplifying a `CalculationValue`](#simplifying-a-calculationvalue)
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* [Semantics](#semantics)
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* [`FunctionExpression` and `Variable`](#functionexpression-and-variable)
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* [`SumExpression` and `ProductExpression`](#sumexpression-and-productexpression)
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* [`SlashListExpression`](#slashlistexpression)
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* [`SpaceListExpression`](#spacelistexpression)
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* [`ParenthesizedExpression`](#parenthesizedexpression)
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* [`InterpolatedIdentifier`](#interpolatedidentifier)
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@ -32,13 +34,13 @@ An expression is "calculation-safe" if it is one of:
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* A [`FunctionExpression`].
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* A `ParenthesizedExpression` whose contents is calculation-safe.
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* A `SumExpression` whose operands are calculation-safe.
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* A `ProductExpression` whose operator is `*` or `/` and whose operands are
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* A `ProductExpression` whose operator is `*` and whose operands are
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calculation-safe.
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* A `Number`.
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* A `Variable`.
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* An `InterpolatedIdentifier`.
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* An unbracketed `SpaceListExpression` with more than one element, whose
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elements are all calculation-safe.
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* An unbracketed `SpaceListExpression` or `SlashListExpression` with more than
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one element, whose elements are all calculation-safe.
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[`FunctionExpression`]: ../functions.md#syntax
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@ -152,13 +154,71 @@ and returns a number or a calculation.
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one or more `RestArgument`s, throw an error.
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* Let `calc` be a calculation whose name is the lower-case value of `call`'s
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name and whose arguments are the result of evaluating each `Expression` in
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`call`'s `ArgumentInvocation` [as a calculation value].
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name and whose arguments are the result of "[adjusting slash precedence] in
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and then evaluating each `Expression`" in `call`'s `ArgumentInvocation` [as a
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calculation value].
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[adjusting slash precedence]: #adjusting-slash-precedence
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[as a calculation value]: #evaluating-an-expression-as-a-calculation-value
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* Return the result of [simplifying](#simplifying-a-calculation) `calc`.
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### Adjusting Slash Precedence
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This algorithm takes a calculation-safe expression `expression` and returns
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another calculation-safe expression with the precedence of
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[`SlashListExpression`]s adjusted to match division precedence.
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[`SlashListExpression`]: list.md#slashlistexpression
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* Return a copy of `expression` except, for each `SlashListExpression`:
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* Let `left` be the first element of the list.
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* For each remaining element `right`:
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* If `left` and `right` are both `SumExpression`s:
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* Let `last-left` be the last operand of `left` and `first-right` the
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first operand of `right`.
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* Set `left` to a `SumExpression` that begins with all operands and
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operators of `left` except `last-left`, followed by a
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`SlashListExpression` with elements `last-left` and `first-right`,
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followed by all operators and operands of `right` except `first-right`.
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> For example, `slash-list(1 + 2, 3 + 4)` becomes `1 + (2 / 3) + 4`.
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* Otherwise, if `left` is a `SumExpression`:
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* Let `last-left` be the last operand of `left`.
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* Set `left` to a `SumExpression` that begins with all operands and
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operators of `left` except `last-left`, followed by a
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`SlashListExpression` with elements `last-left` and `right`.
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> For example, `slash-list(1 + 2, 3)` becomes `1 + (2 / 3)`.
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* Otherwise, if `right` is a `SumExpression` or a `ProductExpression`:
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* Let `first-right` be the first operand of `right`.
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* Set `left` to an expression of the same type as `right` that begins a
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`SlashListExpression` with elements `left` and `first-right`, followed
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by operators and operands of `right` except `first-right`.
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> For example, `slash-list(1, 2 * 3)` becomes `(1 / 2) * 3`.
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* Otherwise, if `left` is a slash-separated list, add `right` to the end.
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* Otherwise, set `left` to a slash-separated list containing `left` and
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`right`.
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* Replace each element in `left` with the result of adjusting slash precedence
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in that element.
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* Replace the `SlashListExpression` with `left` in the returned expression.
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### Evaluating an Expression as a Calculation Value
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This algorithm takes an expression `expression` and returns a
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@ -497,6 +557,21 @@ To evaluate a `SumExpresssion` or a `ProductExpression` as a calculation value:
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* Return `left`.
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### `SlashListExpression`
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To evaluate a `SlashListExpression` as a calculation value:
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* Let `left` be the result of evaluating the first element of the list as a
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calculation value.
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* For each remaining element `element`:
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* Let `right` be the result of evaluating `element` as a calculation value.
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* Set `left` to a `CalcOperation` with operator `"/"`, `left`, and `right`.
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* Return `left`.
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### `SpaceListExpression`
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To evaluate a `SpaceListExpresssion` as a calculation value:
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@ -6,6 +6,9 @@
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* [List](#list)
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* [List Value](#list-value)
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* [Index](#index)
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* [Syntax](#syntax)
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* [Semantics](#semantics)
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* [`SlashListExpression`](#slashlistexpression)
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## Definitions
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@ -44,3 +47,31 @@ absolute value is larger than the length of that list.
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> * `"c"`: 3, -1
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[integer]: number.md#integer
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## Syntax
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<x><pre>
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**BracketedListExpression** ::= '[' ContainedListExpression ']'
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**ContainedListExpression** ::= CommaListExpression ','?
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**CommaListExpression** ::= SlashListExpression (',' SlashListExpression)*
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**SlashListExpression** ::= SpaceListExpression ('/' SpaceListExpression)*
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**SpaceListExpression** ::= SumExpression+
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</pre></x>
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> Note that `/` may *not* be used in single-element lists the way `,` is. That
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> is, `(foo,)` is valid, but `(foo/)` is not.
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>
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> This defines `/` to bind tighter than `,` but looser than space-separated
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> lists. This was chosen because most common uses of `/` in CSS conceptually
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> bind looser than space-separated values. The only exception is the [`font`
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> shorthand syntax], which is used much more rarely will still work (albeit with
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> an unintuitive SassScript representation) with a loose-binding `/`.
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>
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> [`font` shorthand syntax]: https://developer.mozilla.org/en-US/docs/Web/CSS/font
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## Semantics
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### `SlashListExpression`
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To evaluate a `SlashListExpression`, evaluate each of its `SpaceListExpression`s
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and return a slash-separated list that contains each of the results in order.
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@ -14,7 +14,6 @@
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* [Exact Equality](#exact-equality)
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* [Fuzzy Equality](#fuzzy-equality)
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* [Integer](#integer)
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* [Potentially Slash-Separated Number](#potentially-slash-separated-number)
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* [Types](#types)
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* [Operations](#operations)
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* [Equality](#equality)
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@ -210,37 +209,6 @@ If `m` exists, we say that `n`'s *integer value* is the double that represents
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> To avoid ambiguity, specification text will generally use the term
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> "mathematical integer" when referring to the abstract mathematical objects.
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### Potentially Slash-Separated Number
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A Sass number may be *potentially slash-separated*. If it is, it is associated
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with two additional Sass numbers, the *original numerator* and the *original
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denominator*. A number that is not potentially slash-separated is known as
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*slash-free*.
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A potentially slash-separated number is created when a `ProductExpression` with
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a `/` operator is evaluated and each operand is *syntactically* one of the
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following:
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* a `Number`,
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* a [`FunctionCall`], or
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* a `ProductExpression` that can itself create potentially slash-separated
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numbers.
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[`FunctionCall`]: ../functions.md#functioncall
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If the result of evaluating the `ProductExpression` is a number, that number is
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potentially slash-separated if all of the following are true:
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* the results of evaluating both operands were numbers, and
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* if either operand was a `FunctionCall`, it was [evaluated as a calculation]
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and its name was not `"abs"`, `"max"`, `"min"`, or `"round"`.
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[evaluated as a calculation]: calculation.md#evaluating-a-functioncall-as-a-calculation
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If both of these are true, the first operand is the original numerator of the
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potentially slash-separated number returned by the `/` operator, and the second
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is the original denominator.
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## Types
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The value type known as a *number* has three components:
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Block a user