Add • to the tokenization spec

1 files changed, 2 insertions, 1 deletions

diff --git a/docs/spec/token.html b/docs/spec/token.html
index 7209f982..5a258422 100644
--- a/docs/spec/token.html
+++ b/docs/spec/token.html
@@ -10,7 +10,8 @@
 <p>A BQN <em>character literal</em> consists of a single character between single quotes, such as <code><span class='String'>'a'</span></code>, and a <em>string literal</em> consists of any number of characters between double quotes, such as <code><span class='String'>&quot;&quot;</span></code> or <code><span class='String'>&quot;abc&quot;</span></code>. Character and string literals take precedence with comments over other tokenization rules, so that <code><span class='Comment'>#</span></code> between quotes does not start a comment and whitespace between quotes is not removed, but a quote within a comment does not start a character literal. Almost any character can be included directly in a character or string literal without escaping. The only exception is the double quote character <code><span class='String'>&quot;</span></code>, which must be written twice to include it in a string, as otherwise it would end the string instead. Character literals require no escaping at all, as the length is fixed. In particular, literals for the double and single quote characters are written <code><span class='String'>'''</span></code> and <code><span class='String'>'&quot;'</span></code>, while length-1 strings containing these characters are <code><span class='String'>&quot;'&quot;</span></code> and <code><span class='String'>&quot;&quot;&quot;&quot;</span></code>.</p>
 <p>A comment consists of the hash character <code><span class='Comment'>#</span></code> and any following text until (not including) the next newline character. The initial <code><span class='Comment'>#</span></code> must not be part of a string literal started earlier. Comments are ignored entirely and do not form tokens.</p>
 <p>Identifiers and numeric literals share the same token formation rule. These tokens are formed from the <em>numeric characters</em> <code><span class='Number'>¯∞π0123456789</span></code> and <em>alphabetic characters</em> <code><span class='Modifier'>_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ</span></code> and the oddball <code><span class='Value'>𝕣</span></code>. Additionally, <code><span class='Value'>.</span></code> is considered a numeric character if it is followed immediately by a digit (<code><span class='Number'>0123456789</span></code>); otherwise it forms its own token. Any sequence of these characters adjacent to each other forms a single token, which is a <em>numeric literal</em> if it begins with a numeric character and an <em>identifier</em> if it begins with an alphabetic character. If a token begins with an underscore then its first non-underscore character must be alphabetic: for example, <code><span class='Modifier'>_99</span></code> is not a valid token. Numeric literals are also subject to <a href="literal.html">numeric literal rules</a>, which specify which numeric literals are valid and which numbers they represent. If the token contains <code><span class='Value'>𝕣</span></code> it must be either <code><span class='Value'>𝕣</span></code>, <code><span class='Modifier'>_𝕣</span></code>, or <code><span class='Modifier2'>_𝕣_</span></code> and is considered a special name (see below). As the value taken by this identifier can only be a modifier, the uppercase character <code><span class='Value'>ℝ</span></code> is not allowed.</p>
-<p>Following this step, the whitespace characters space and tab are ignored, and do not form tokens. Only these whitespace characters, and the newline character, which does form a token, are allowed.</p>
+<p>The <em>system dot</em> <code><span class='Value'>•</span></code> always attaches to the token containing the next character, which must not be a whitespace character or <code><span class='Comment'>#</span></code>. This combined token is valid only if its name matches a defined <a href="system.html">system value</a>, ignoring underscores and letter case as with identifiers (but in the unlikely case that system values with numeric names are defined, they need not follow the numeric literal rules). Its role is the same as the role the remainder of the token would have if not preceded by <code><span class='Value'>•</span></code>, and it is considered a literal for grammar purposes.</p>
+<p>Following these steps, the whitespace characters space and tab are ignored, and do not form tokens. Only these whitespace characters, and the newline character, which does form a token, are allowed.</p>
 <p>Otherwise, a single character forms a token. Only the specified set of characters can be used; others result in an error. The classes of characters are given below.</p>
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