Syntactic highlighting of NAME_REF for injections

This commit adds a function that tries to determine the syntax highlighting class of NAME_REFs based on the usage.
It is used for highlighting injections (such as highlighting of doctests) as the semantic logic will most of the time result in unresolved references.
It also adds a color to unresolved references in HTML encoding.

6 files changed, 22 insertions, 6 deletions

diff --git a/crates/ra_ide/src/snapshots/highlight_doctest.html b/crates/ra_ide/src/snapshots/highlight_doctest.html
index 0ae8c7efc..5228df267 100644
--- a/crates/ra_ide/src/snapshots/highlight_doctest.html
+++ b/crates/ra_ide/src/snapshots/highlight_doctest.html
@@ -25,22 +25,29 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .variable           { color: #DCDCCC; }
 .format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
+.unresolved_reference { color: #FC5555; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }
 .keyword.unsafe     { color: #BC8383; font-weight: bold; }
 .control            { font-style: italic; }
 </style>
-<pre><code><span class="keyword">impl</span> <span class="unresolved_reference">Foo</span> {
+<pre><code><span class="keyword">struct</span> <span class="struct declaration">Foo</span> {
+    <span class="field declaration">bar</span>: <span class="builtin_type">bool</span>,
+}
+
+<span class="keyword">impl</span> <span class="struct">Foo</span> {
+    <span class="keyword">pub</span> <span class="keyword">const</span> <span class="constant declaration">bar</span>: <span class="builtin_type">bool</span> = <span class="bool_literal">true</span>;
+
     <span class="comment">/// Constructs a new `Foo`.</span>
     <span class="comment">///</span>
     <span class="comment">/// # Examples</span>
     <span class="comment">///</span>
     <span class="comment">/// ```</span>
     <span class="comment">/// #</span> <span class="attribute">#![</span><span class="function attribute">allow</span><span class="attribute">(unused_mut)]</span>
-    <span class="comment">/// </span><span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">foo</span>: <span class="unresolved_reference">Foo</span> = <span class="unresolved_reference">Foo</span>::<span class="unresolved_reference">new</span>();
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">foo</span>: <span class="struct">Foo</span> = <span class="struct">Foo</span>::<span class="function">new</span>();
     <span class="comment">/// ```</span>
-    <span class="keyword">pub</span> <span class="keyword">const</span> <span class="keyword">fn</span> <span class="function declaration">new</span>() -&gt; <span class="unresolved_reference">Foo</span> {
-        <span class="unresolved_reference">Foo</span> { }
+    <span class="keyword">pub</span> <span class="keyword">const</span> <span class="keyword">fn</span> <span class="function declaration">new</span>() -&gt; <span class="struct">Foo</span> {
+        <span class="struct">Foo</span> { <span class="field">bar</span>: <span class="bool_literal">true</span> }
     }
 
     <span class="comment">/// `bar` method on `Foo`.</span>
@@ -48,11 +55,15 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="comment">/// # Examples</span>
     <span class="comment">///</span>
     <span class="comment">/// ```</span>
-    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">foo</span> = <span class="unresolved_reference">Foo</span>::<span class="unresolved_reference">new</span>();
+    <span class="comment">/// </span><span class="keyword">use</span> <span class="module">x</span>::<span class="module">y</span>;
+    <span class="comment">///</span>
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">foo</span> = <span class="struct">Foo</span>::<span class="function">new</span>();
     <span class="comment">///</span>
     <span class="comment">/// </span><span class="comment">// calls bar on foo</span>
     <span class="comment">/// </span><span class="macro">assert!</span>(foo.bar());
     <span class="comment">///</span>
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">bar</span> = <span class="variable">foo</span>.<span class="field">bar</span> || <span class="struct">Foo</span>::<span class="constant">bar</span>;
+    <span class="comment">///</span>
     <span class="comment">/// </span><span class="comment">/* multi-line
     </span><span class="comment">/// </span><span class="comment">       comment */</span>
     <span class="comment">///</span>
@@ -63,7 +74,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="comment">/// ```</span>
     <span class="comment">///</span>
     <span class="comment">/// ```</span>
-    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">foobar</span> = <span class="unresolved_reference">Foo</span>::<span class="unresolved_reference">new</span>().<span class="unresolved_reference">bar</span>();
+    <span class="comment">/// </span><span class="keyword">let</span> <span class="variable declaration">foobar</span> = <span class="struct">Foo</span>::<span class="function">new</span>().<span class="function">bar</span>();
     <span class="comment">/// ```</span>
     <span class="keyword">pub</span> <span class="keyword">fn</span> <span class="function declaration">foo</span>(&<span class="self_keyword">self</span>) -&gt; <span class="builtin_type">bool</span> {
         <span class="bool_literal">true</span>
diff --git a/crates/ra_ide/src/snapshots/highlight_injection.html b/crates/ra_ide/src/snapshots/highlight_injection.html
index dec06eb51..e1c9d3523 100644
--- a/crates/ra_ide/src/snapshots/highlight_injection.html
+++ b/crates/ra_ide/src/snapshots/highlight_injection.html
@@ -25,6 +25,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .variable           { color: #DCDCCC; }
 .format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
+.unresolved_reference { color: #FC5555; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }
 .keyword.unsafe     { color: #BC8383; font-weight: bold; }
diff --git a/crates/ra_ide/src/snapshots/highlight_strings.html b/crates/ra_ide/src/snapshots/highlight_strings.html
index 849eb3b73..666b48fd0 100644
--- a/crates/ra_ide/src/snapshots/highlight_strings.html
+++ b/crates/ra_ide/src/snapshots/highlight_strings.html
@@ -25,6 +25,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .variable           { color: #DCDCCC; }
 .format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
+.unresolved_reference { color: #FC5555; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }
 .keyword.unsafe     { color: #BC8383; font-weight: bold; }
diff --git a/crates/ra_ide/src/snapshots/highlight_unsafe.html b/crates/ra_ide/src/snapshots/highlight_unsafe.html
index bd24e6e38..e1540499b 100644
--- a/crates/ra_ide/src/snapshots/highlight_unsafe.html
+++ b/crates/ra_ide/src/snapshots/highlight_unsafe.html
@@ -25,6 +25,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .variable           { color: #DCDCCC; }
 .format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
+.unresolved_reference { color: #FC5555; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }
 .keyword.unsafe     { color: #BC8383; font-weight: bold; }
diff --git a/crates/ra_ide/src/snapshots/highlighting.html b/crates/ra_ide/src/snapshots/highlighting.html
index 5c2ff6ab5..52912dc93 100644
--- a/crates/ra_ide/src/snapshots/highlighting.html
+++ b/crates/ra_ide/src/snapshots/highlighting.html
@@ -25,6 +25,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .variable           { color: #DCDCCC; }
 .format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
+.unresolved_reference { color: #FC5555; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }
 .keyword.unsafe     { color: #BC8383; font-weight: bold; }
diff --git a/crates/ra_ide/src/snapshots/rainbow_highlighting.html b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
index 1ab06182c..1d7f04882 100644
--- a/crates/ra_ide/src/snapshots/rainbow_highlighting.html
+++ b/crates/ra_ide/src/snapshots/rainbow_highlighting.html
@@ -25,6 +25,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
 .variable           { color: #DCDCCC; }
 .format_specifier   { color: #CC696B; }
 .mutable            { text-decoration: underline; }
+.unresolved_reference { color: #FC5555; }
 
 .keyword            { color: #F0DFAF; font-weight: bold; }
 .keyword.unsafe     { color: #BC8383; font-weight: bold; }