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[spec] Cosmetic changes in the lexical syntax chapter #18608

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Sep 28, 2023
Merged

[spec] Cosmetic changes in the lexical syntax chapter #18608

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bd19d15
[spec] Remove highlighting in the lists of keywords.
sjrd Sep 28, 2023
b4ce684
[spec] Fix the GitHub URL to edit the spec files.
sjrd Sep 28, 2023
18c8f91
[spec] Better align EBNF grammars in the lexical syntax chapter.
sjrd Sep 28, 2023
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53 changes: 25 additions & 28 deletions docs/_spec/01-lexical-syntax.md
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Expand Up @@ -43,17 +43,17 @@ colon ::= ':' -- with side conditions explained above
## Identifiers

```ebnf
op ::= opchar {opchar}
varid ::= lower idrest
boundvarid ::= varid
| ‘`’ varid ‘`’
alphaid ::= upper idrest
| varid
plainid ::= alphaid
| op
id ::= plainid
| ‘`’ { charNoBackQuoteOrNewline | escapeSeq } ‘`’
idrest ::= {letter | digit} [‘_’ op]
op ::= opchar {opchar}
varid ::= lower idrest
boundvarid ::= varid
| ‘`’ varid ‘`’
alphaid ::= upper idrest
| varid
plainid ::= alphaid
| op
id ::= plainid
| ‘`’ { charNoBackQuoteOrNewline | escapeSeq } ‘`’
idrest ::= {letter | digit} [‘_’ op]
escapeSeq ::= UnicodeEscape | charEscapeSeq
UnicodeEscape ::= ‘\’ ‘u’ {‘u’} hexDigit hexDigit hexDigit hexDigit
hexDigit ::= ‘0’ | ... | ‘9’ | ‘A’ | ... | ‘F’ | ‘a’ | ... | ‘f’
Expand Down Expand Up @@ -83,7 +83,7 @@ For this purpose, lower case letters include not only a-z, but also all characte

The following are examples of variable identifiers:

> ```scala
> ```
> x maxIndex p2p empty_?
> `yield` αρετη _y dot_product_*
> __system _MAX_LEN_
Expand All @@ -92,7 +92,7 @@ The following are examples of variable identifiers:

Some examples of constant identifiers are

> ```scala
> ```
> + Object $reserved Džul ǂnûm
> ⅰ_ⅲ Ⅰ_Ⅲ ↁelerious ǃqhàà ʹthatsaletter
> ```
Expand All @@ -104,7 +104,7 @@ User programs should not define identifiers that contain ‘$’ characters.

The following names are reserved words instead of being members of the syntactic class `id` of lexical identifiers.

```scala
```
abstract case catch class def do else
enum export extends false final finally for
given if implicit import lazy match new
Expand Down Expand Up @@ -169,17 +169,16 @@ A newline in a Scala source text is treated as the special token “nl” if the

The tokens that can terminate a statement are: literals, identifiers and the following delimiters and reserved words:

```scala
```
this null true false return type <xml-start>
_ ) ] }
```

The tokens that can begin a statement are all Scala tokens _except_ the following delimiters and reserved words:

```scala
catch else extends finally forSome match
with yield , . ; : = => <- <: <%
>: # [ ) ] }
```
catch else extends finally forSome match with yield
, . ; : = => <- <: <% >: # [ ) ] }
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Suggested change
, . ; : = => <- <: <% >: # [ ) ] }
, . ; : = => <- <: <% >: # ) ] }

looks like this can go due to polymorphic lambdas now being added

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Ah, good point. That's a normative change, though, so I'll do that in a separate PR.

```

A `case` token can begin a statement only if followed by a
Expand Down Expand Up @@ -334,8 +333,7 @@ Literal ::= [‘-’] integerLiteral
### Integer Literals

```ebnf
integerLiteral ::= (decimalNumeral | hexNumeral)
[‘L’ | ‘l’]
integerLiteral ::= (decimalNumeral | hexNumeral) [‘L’ | ‘l’]
decimalNumeral ::= ‘0’ | digit [{digit | ‘_’} digit]
hexNumeral ::= ‘0’ (‘x’ | ‘X’) hexDigit [{hexDigit | ‘_’} hexDigit]
```
Expand Down Expand Up @@ -366,11 +364,10 @@ The digits of a numeric literal may be separated by arbitrarily many underscores
### Floating Point Literals

```ebnf
floatingPointLiteral
::= [decimalNumeral] ‘.’ digit [{digit | ‘_’} digit] [exponentPart] [floatType]
| decimalNumeral exponentPart [floatType]
| decimalNumeral floatType
exponentPart ::= (‘E’ | ‘e’) [‘+’ | ‘-’] digit [{digit | ‘_’} digit]
floatingPointLiteral ::= [decimalNumeral] ‘.’ digit [{digit | ‘_’} digit] [exponentPart] [floatType]
| decimalNumeral exponentPart [floatType]
| decimalNumeral floatType
exponentPart ::= (‘E’ | ‘e’) [‘+’ | ‘-’] digit [{digit | ‘_’} digit]
```

Floating point literals are of type `Float` when followed by a floating point type suffix `F` or `f`, and are of type `Double` otherwise.
Expand Down Expand Up @@ -452,7 +449,7 @@ Characters must not necessarily be printable; newlines or other control characte
>
> This would produce the string:
>
> ```scala
> ```
> the present string
> spans three
> lines.
Expand All @@ -469,7 +466,7 @@ Characters must not necessarily be printable; newlines or other control characte
>
> evaluates to
>
> ```scala
> ```
> the present string
> spans three
> lines.
Expand Down
2 changes: 1 addition & 1 deletion docs/_spec/_layouts/default.yml
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Expand Up @@ -27,7 +27,7 @@
<header class="hidden-print">
<nav id="chapters">
<a href="{{site.baseurl}}/" title="Table of Contents">Scala {{ site.thisScalaVersion }}</a>
<a id="github" href="https://github.com/scala/scala/tree/2.13.x/spec"><img src="public/images/[email protected]" alt="Edit at GitHub"></a>
<a id="github" href="https://github.com/lampepfl/dotty/tree/main/docs/_spec"><img src="public/images/[email protected]" alt="Edit at GitHub"></a>
{% assign sorted_pages = site.pages | sort:"name" %}
{% for post in sorted_pages %}
{% if post.chapter >= 0 %}
Expand Down
2 changes: 1 addition & 1 deletion docs/_spec/_layouts/toc.yml
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Expand Up @@ -20,7 +20,7 @@
<div id="header-main">
<img id="scala-logo" src="public/images/scala-spiral-white.png" />
<span id="title">Scala Language Specification</span>
<a id="github" href="https://github.com/scala/scala/tree/{{ site.thisScalaVersion }}.x/spec"><img src="public/images/[email protected]" alt="Edit at GitHub"></a>
<a id="github" href="https://github.com/lampepfl/dotty/tree/main/docs/_spec"><img src="public/images/[email protected]" alt="Edit at GitHub"></a>
</div>
<div id="header-sub">Version {{ site.thisScalaVersion }}</div>
</header>
Expand Down