Rollup merge of #90630 - GuillaumeGomez:improve-rustdoc-search, r=notriddle

Create real parser for search queries

You can test it [here](https://rustdoc.crud.net/imperio/improve-rustdoc-search/std/index.html).

This PR adds a real parser for the query engine in rustdoc. The parser is quite simple but it allows to makes query handling much easier. I added a new testsuite to ensure it works as expected and ran fuzzing checks on it for a few hours without problems.

So about the parser: as you can see in the screenshot, it handles recursive generics parsing. It also allows to set which item should use exact matching by adding double-quotes around it (look for `exact_search` in the screenshot).

Now about the query engine itself: I simplified it a lot thanks to the parsed query. It behaves mostly the same when there is only one argument, but is much more powerful when there are more than one.

When making this change, we also removed the support for multi-query.

PS: A big part of the PR is tests and test-related code. :)

r? `@camelid`

1 files changed, 365 insertions, 0 deletions

diff --git a/src/test/rustdoc-js-std/parser-errors.js b/src/test/rustdoc-js-std/parser-errors.js
new file mode 100644
index 00000000000..779ab867c12
--- /dev/null
+++ b/src/test/rustdoc-js-std/parser-errors.js
@@ -0,0 +1,365 @@
+const QUERY = [
+    '<P>',
+    '-> <P>',
+    'a<"P">',
+    '"P" "P"',
+    'P "P"',
+    '"p" p',
+    '"const": p',
+    "a<:a>",
+    "a<::a>",
+    "((a))",
+    "(p -> p",
+    "::a::b",
+    "a::::b",
+    "a::b::",
+    ":a",
+    "a b:",
+    "a (b:",
+    "_:",
+    "a-bb",
+    "a>bb",
+    "ab'",
+    "a->",
+    '"p" <a>',
+    '"p" a<a>',
+    "a,<",
+    "aaaaa<>b",
+    "fn:aaaaa<>b",
+    "->a<>b",
+    "a<->",
+    "a:: a",
+    "a ::a",
+    "a<a>:",
+    "a<>:",
+    "a,:",
+    "  a<>  :",
+    "mod : :",
+];
+
+const PARSED = [
+    {
+        elems: [],
+        foundElems: 0,
+        original: "<P>",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "<p>",
+        error: "Found generics without a path",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "-> <P>",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "-> <p>",
+        error: "Found generics without a path",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a<\"P\">",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a<\"p\">",
+        error: "`\"` cannot be used in generics",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "\"P\" \"P\"",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "\"p\" \"p\"",
+        error: "Cannot have more than one literal search element",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "P \"P\"",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "p \"p\"",
+        error: "Cannot use literal search when there is more than one element",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "\"p\" p",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "\"p\" p",
+        error: "You cannot have more than one element if you use quotes",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "\"const\": p",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "\"const\": p",
+        error: "You cannot use quotes on type filter",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a<:a>",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a<:a>",
+        error: "Unexpected `:` after `<`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a<::a>",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a<::a>",
+        error: "Unexpected `::`: paths cannot start with `::`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "((a))",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "((a))",
+        error: "Unexpected `(`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "(p -> p",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "(p -> p",
+        error: "Unexpected `(`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "::a::b",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "::a::b",
+        error: "Paths cannot start with `::`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a::::b",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a::::b",
+        error: "Unexpected `::::`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a::b::",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a::b::",
+        error: "Paths cannot end with `::`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: ":a",
+        returned: [],
+        typeFilter: -1,
+        userQuery: ":a",
+        error: "Expected type filter before `:`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a b:",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a b:",
+        error: "Unexpected `:`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a (b:",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a (b:",
+        error: "Unexpected `(`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "_:",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "_:",
+        error: "Unknown type filter `_`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a-bb",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a-bb",
+        error: "Unexpected `-` (did you mean `->`?)",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a>bb",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a>bb",
+        error: "Unexpected `>` (did you mean `->`?)",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "ab'",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "ab'",
+        error: "Unexpected `'`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a->",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a->",
+        error: "Expected at least one item after `->`",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: '"p" <a>',
+        returned: [],
+        typeFilter: -1,
+        userQuery: '"p" <a>',
+        error: "Found generics without a path",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: '"p" a<a>',
+        returned: [],
+        typeFilter: -1,
+        userQuery: '"p" a<a>',
+        error: "You cannot have more than one element if you use quotes",
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: 'a,<',
+        returned: [],
+        typeFilter: -1,
+        userQuery: 'a,<',
+        error: 'Found generics without a path',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: 'aaaaa<>b',
+        returned: [],
+        typeFilter: -1,
+        userQuery: 'aaaaa<>b',
+        error: 'Expected `,`, ` `, `:` or `->`, found `b`',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: 'fn:aaaaa<>b',
+        returned: [],
+        typeFilter: -1,
+        userQuery: 'fn:aaaaa<>b',
+        error: 'Expected `,`, ` ` or `->`, found `b`',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: '->a<>b',
+        returned: [],
+        typeFilter: -1,
+        userQuery: '->a<>b',
+        error: 'Expected `,` or ` `, found `b`',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: 'a<->',
+        returned: [],
+        typeFilter: -1,
+        userQuery: 'a<->',
+        error: 'Unexpected `-` after `<`',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: 'a:: a',
+        returned: [],
+        typeFilter: -1,
+        userQuery: 'a:: a',
+        error: 'Paths cannot end with `::`',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: 'a ::a',
+        returned: [],
+        typeFilter: -1,
+        userQuery: 'a ::a',
+        error: 'Paths cannot start with `::`',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a<a>:",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a<a>:",
+        error: 'Unexpected `:`',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a<>:",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a<>:",
+        error: 'Unexpected `<` in type filter',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a,:",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a,:",
+        error: 'Unexpected `,` in type filter',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "a<>  :",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "a<>  :",
+        error: 'Unexpected `<` in type filter',
+    },
+    {
+        elems: [],
+        foundElems: 0,
+        original: "mod : :",
+        returned: [],
+        typeFilter: -1,
+        userQuery: "mod : :",
+        error: 'Unexpected `:`',
+    },
+];