Split up the URLPattern implementation (#36391)

The current implementation is already rather large at ~2.5k lines (~2k
LoC). There is still quite a lot of functionality left to implement, so
let's split it up while it's still manageable.

Testing: Covered by existing web platform tests

Signed-off-by: Simon Wülker <simon.wuelker@arcor.de>

1 files changed, 473 insertions, 0 deletions

diff --git a/components/script/dom/urlpattern/pattern_parser.rs b/components/script/dom/urlpattern/pattern_parser.rs
new file mode 100644
index 00000000000..3147c5649f4
--- /dev/null
+++ b/components/script/dom/urlpattern/pattern_parser.rs
@@ -0,0 +1,473 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use script_bindings::error::{Error, Fallible};
+
+use crate::dom::urlpattern::tokenizer::{Token, TokenType, TokenizePolicy, tokenize};
+use crate::dom::urlpattern::{
+    EncodingCallback, FULL_WILDCARD_REGEXP_VALUE, Options, Part, PartModifier, PartType,
+    generate_a_segment_wildcard_regexp,
+};
+
+/// <https://urlpattern.spec.whatwg.org/#parse-a-pattern-string>
+pub(super) fn parse_a_pattern_string(
+    input: &str,
+    options: Options,
+    encoding_callback: EncodingCallback,
+) -> Fallible<Vec<Part>> {
+    // Step 1. Let parser be a new pattern parser whose encoding callback is encoding callback and
+    // segment wildcard regexp is the result of running generate a segment wildcard regexp given options.
+    let mut parser = PatternParser::new(
+        generate_a_segment_wildcard_regexp(options),
+        encoding_callback,
+    );
+
+    // Step 2. Set parser’s token list to the result of running tokenize given input and "strict".
+    parser.token_list = tokenize(input, TokenizePolicy::Strict)?;
+
+    // Step 3. While parser’s index is less than parser’s token list’s size:
+    while parser.index < parser.token_list.len() {
+        // Step 3.1 Let char token be the result of running try to consume a token given parser and "char".
+        let char_token = parser.try_to_consume_a_token(TokenType::Char);
+
+        // Step 3.2 Let name token be the result of running try to consume a token given parser and "name".
+        let mut name_token = parser.try_to_consume_a_token(TokenType::Name);
+
+        // Step 3.3 Let regexp or wildcard token be the result of running try to consume a
+        // regexp or wildcard token given parser and name token.
+        let mut regexp_or_wildcard_token =
+            parser.try_to_consume_a_regexp_or_wildcard_token(name_token);
+
+        // Step 3.4 If name token is not null or regexp or wildcard token is not null:
+        if name_token.is_some() || regexp_or_wildcard_token.is_some() {
+            // Step 3.4.1 Let prefix be the empty string.
+            let mut prefix = "";
+
+            // Step 3.4.2 If char token is not null then set prefix to char token’s value.
+            if let Some(char_token) = char_token {
+                prefix = char_token.value;
+            }
+
+            // Step 3.4.3 If prefix is not the empty string and not options’s prefix code point:
+            let prefix_is_prefix_code_point = options.prefix_code_point.is_some_and(|c| {
+                let mut buffer = [0; 4];
+                prefix == c.encode_utf8(&mut buffer)
+            });
+            if !prefix.is_empty() && !prefix_is_prefix_code_point {
+                // Step 3.4.3.1 Append prefix to the end of parser’s pending fixed value.
+                parser.pending_fixed_value.push_str(prefix);
+
+                // Step 3.4.3.2 Set prefix to the empty string.
+                prefix = "";
+            }
+
+            // Step 3.4.4 Run maybe add a part from the pending fixed value given parser.
+            parser.maybe_add_a_part_from_the_pending_fixed_value()?;
+
+            // Step 3.4.5 Let modifier token be the result of running try to consume a modifier token given parser.
+            let modifier_token = parser.try_to_consume_a_modifier_token();
+
+            // Step 3.4.6 Run add a part given parser, prefix, name token, regexp or wildcard token,
+            // the empty string, and modifier token.
+            parser.add_a_part(
+                prefix,
+                name_token,
+                regexp_or_wildcard_token,
+                "",
+                modifier_token,
+            )?;
+
+            // Step 3.4.7 Continue.
+            continue;
+        }
+
+        // Step 3.5 Let fixed token be char token.
+        let mut fixed_token = char_token;
+
+        // Step 3.6 If fixed token is null, then set fixed token to the result of running
+        // try to consume a token given parser and "escaped-char".
+        if fixed_token.is_none() {
+            fixed_token = parser.try_to_consume_a_token(TokenType::EscapedChar);
+        }
+
+        // Step 3.7 If fixed token is not null:
+        if let Some(fixed_token) = fixed_token {
+            // Step 3.7.1 Append fixed token’s value to parser’s pending fixed value.
+            parser.pending_fixed_value.push_str(fixed_token.value);
+
+            // Step 3.7.2 Continue.
+            continue;
+        }
+
+        // Step 3.8 Let open token be the result of running try to consume a token given parser and "open".
+        let open_token = parser.try_to_consume_a_token(TokenType::Open);
+
+        // Step 3.9 If open token is not null:
+        if open_token.is_some() {
+            // Step 3.9.1 Let prefix be the result of running consume text given parser.
+            let prefix = parser.consume_text();
+
+            // Step 3.9.2 Set name token to the result of running try to consume a token given parser and "name".
+            name_token = parser.try_to_consume_a_token(TokenType::Name);
+
+            // Step 3.9.3 Set regexp or wildcard token to the result of running try to consume a regexp or wildcard
+            // token given parser and name token.
+            regexp_or_wildcard_token = parser.try_to_consume_a_regexp_or_wildcard_token(name_token);
+
+            // Step 3.9.4 Let suffix be the result of running consume text given parser.
+            let suffix = parser.consume_text();
+
+            // Step 3.9.5 Run consume a required token given parser and "close".
+            parser.consume_a_required_token(TokenType::Close)?;
+
+            // Step 3.9.6 Let modifier token be the result of running try to consume a modifier token given parser.
+            let modifier_token = parser.try_to_consume_a_modifier_token();
+
+            // Step 3.9.7 Run add a part given parser, prefix, name token, regexp or wildcard token,
+            // suffix, and modifier token.
+            parser.add_a_part(
+                &prefix,
+                name_token,
+                regexp_or_wildcard_token,
+                &suffix,
+                modifier_token,
+            )?;
+
+            // Step 3.9.8 Continue.
+            continue;
+        }
+
+        // Step 3.10 Run maybe add a part from the pending fixed value given parser.
+        parser.maybe_add_a_part_from_the_pending_fixed_value()?;
+
+        // Step 3.11 Run consume a required token given parser and "end".
+        parser.consume_a_required_token(TokenType::End)?;
+    }
+
+    Ok(parser.part_list)
+}
+
+/// <https://urlpattern.spec.whatwg.org/#pattern-parser>
+struct PatternParser<'a> {
+    /// <https://urlpattern.spec.whatwg.org/#pattern-parser-token-list>
+    token_list: Vec<Token<'a>>,
+
+    /// <https://urlpattern.spec.whatwg.org/#pattern-parser-encoding-callback>
+    encoding_callback: EncodingCallback,
+
+    /// <https://urlpattern.spec.whatwg.org/#pattern-parser-segment-wildcard-regexp>
+    segment_wildcard_regexp: String,
+
+    /// <https://urlpattern.spec.whatwg.org/#pattern-parser-part-list>
+    part_list: Vec<Part>,
+
+    /// <https://urlpattern.spec.whatwg.org/#pattern-parser-pending-fixed-value>
+    pending_fixed_value: String,
+
+    /// <https://urlpattern.spec.whatwg.org/#pattern-parser-index>
+    index: usize,
+
+    /// <https://urlpattern.spec.whatwg.org/#pattern-parser-next-numeric-name>
+    next_numeric_name: usize,
+}
+
+impl<'a> PatternParser<'a> {
+    fn new(segment_wildcard_regexp: String, encoding_callback: EncodingCallback) -> Self {
+        Self {
+            token_list: vec![],
+            segment_wildcard_regexp,
+            part_list: vec![],
+            pending_fixed_value: String::new(),
+            index: 0,
+            next_numeric_name: 0,
+            encoding_callback,
+        }
+    }
+
+    /// <https://urlpattern.spec.whatwg.org/#try-to-consume-a-token>
+    fn try_to_consume_a_token(&mut self, token_type: TokenType) -> Option<Token<'a>> {
+        // Step 1. Assert: parser’s index is less than parser’s token list size.
+        debug_assert!(self.index < self.token_list.len());
+
+        // Step 2. Let next token be parser’s token list[parser’s index].
+        let next_token = self.token_list[self.index];
+
+        // Step 3. If next token’s type is not type return null.
+        if next_token.token_type != token_type {
+            return None;
+        }
+
+        // Step 4. Increment parser’s index by 1.
+        self.index += 1;
+
+        // Step 5. Return next token.
+        Some(next_token)
+    }
+
+    /// <https://urlpattern.spec.whatwg.org/#try-to-consume-a-modifier-token>
+    fn try_to_consume_a_modifier_token(&mut self) -> Option<Token<'a>> {
+        // Step 1. Let token be the result of running try to consume a token given parser and "other-modifier".
+        let token = self.try_to_consume_a_token(TokenType::OtherModifier);
+
+        // Step 2. If token is not null, then return token.
+        if token.is_some() {
+            return token;
+        }
+
+        // Step 3. Set token to the result of running try to consume a token given parser and "asterisk".
+        let token = self.try_to_consume_a_token(TokenType::Asterisk);
+
+        // Step 4. Return token.
+        token
+    }
+
+    /// <https://urlpattern.spec.whatwg.org/#consume-a-required-token>
+    fn consume_a_required_token(&mut self, token_type: TokenType) -> Fallible<Token<'a>> {
+        // Step 1. Let result be the result of running try to consume a token given parser and type.
+        let result = self.try_to_consume_a_token(token_type);
+
+        // Step 2. If result is null, then throw a TypeError.
+        let Some(result) = result else {
+            return Err(Error::Type(format!(
+                "Missing required token {token_type:?}"
+            )));
+        };
+
+        // Step 3. Return result.
+        Ok(result)
+    }
+
+    /// <https://urlpattern.spec.whatwg.org/#try-to-consume-a-regexp-or-wildcard-token>
+    fn try_to_consume_a_regexp_or_wildcard_token(
+        &mut self,
+        name_token: Option<Token<'a>>,
+    ) -> Option<Token<'a>> {
+        // Step 1. Let token be the result of running try to consume a token given parser and "regexp".
+        let mut token = self.try_to_consume_a_token(TokenType::Regexp);
+
+        // Step 2. If name token is null and token is null, then set token to the result of running
+        // try to consume a token given parser and "asterisk".
+        if name_token.is_none() && token.is_none() {
+            token = self.try_to_consume_a_token(TokenType::Asterisk);
+        }
+
+        // Step 3. Return token.
+        token
+    }
+
+    /// <https://urlpattern.spec.whatwg.org/#maybe-add-a-part-from-the-pending-fixed-value>
+    fn maybe_add_a_part_from_the_pending_fixed_value(&mut self) -> Fallible<()> {
+        // Step 1. If parser’s pending fixed value is the empty string, then return.
+        if self.pending_fixed_value.is_empty() {
+            return Ok(());
+        }
+
+        // Step 2. Let encoded value be the result of running parser’s encoding callback
+        // given parser’s pending fixed value.
+        let encoded_value = (self.encoding_callback)(&self.pending_fixed_value)?;
+
+        // Step 3. Set parser’s pending fixed value to the empty string.
+        self.pending_fixed_value.clear();
+
+        // Step 4. Let part be a new part whose type is "fixed-text", value is encoded value, and modifier is "none".
+        let part = Part::new(PartType::FixedText, encoded_value, PartModifier::None);
+
+        // Step 5. Append part to parser’s part list.
+        self.part_list.push(part);
+
+        Ok(())
+    }
+
+    /// <https://urlpattern.spec.whatwg.org/#add-a-part>
+    fn add_a_part(
+        &mut self,
+        prefix: &str,
+        name_token: Option<Token<'a>>,
+        regexp_or_wildcard_token: Option<Token<'a>>,
+        suffix: &str,
+        modifier_token: Option<Token<'a>>,
+    ) -> Fallible<()> {
+        // Step 1. Let modifier be "none".
+        let mut modifier = PartModifier::None;
+
+        // Step 2. If modifier token is not null:
+        if let Some(modifier_token) = modifier_token {
+            // Step 2.1 If modifier token’s value is "?" then set modifier to "optional".
+            if modifier_token.value == "?" {
+                modifier = PartModifier::Optional;
+            }
+            // Step 2.2 Otherwise if modifier token’s value is "*" then set modifier to "zero-or-more".
+            else if modifier_token.value == "*" {
+                modifier = PartModifier::ZeroOrMore;
+            }
+            // Step 2.3 Otherwise if modifier token’s value is "+" then set modifier to "one-or-more".
+            else if modifier_token.value == "+" {
+                modifier = PartModifier::OneOrMore;
+            }
+        }
+
+        // Step 3. If name token is null and regexp or wildcard token is null and modifier is "none":
+        if name_token.is_none() &&
+            regexp_or_wildcard_token.is_none() &&
+            modifier == PartModifier::None
+        {
+            // Step 3.1 Append prefix to the end of parser’s pending fixed value.
+            self.pending_fixed_value.push_str(prefix);
+
+            // Step 3.2 Return
+            return Ok(());
+        }
+
+        // Step 4. Run maybe add a part from the pending fixed value given parser.
+        self.maybe_add_a_part_from_the_pending_fixed_value()?;
+
+        // Step 5. If name token is null and regexp or wildcard token is null:
+        if name_token.is_none() && regexp_or_wildcard_token.is_none() {
+            // Step 5.1 Assert: suffix is the empty string.
+            debug_assert!(suffix.is_empty());
+
+            // Step 5.2 If prefix is the empty string, then return.
+            if prefix.is_empty() {
+                return Ok(());
+            }
+
+            // Step 5.3 Let encoded value be the result of running parser’s encoding callback given prefix.
+            let encoded_value = (self.encoding_callback)(prefix)?;
+
+            // Step 5.4 Let part be a new part whose type is "fixed-text",
+            // value is encoded value, and modifier is modifier.
+            let part = Part::new(PartType::FixedText, encoded_value, modifier);
+
+            // Step 5.5 Append part to parser’s part list.
+            self.part_list.push(part);
+
+            // Step 6. Return.
+            return Ok(());
+        }
+
+        // Step 6. Let regexp value be the empty string.
+        let mut regexp_value = {
+            // Step 7. If regexp or wildcard token is null, then set regexp value to parser’s segment wildcard regexp.
+            match regexp_or_wildcard_token {
+                None => self.segment_wildcard_regexp.clone(),
+                Some(token) => {
+                    // Step 8. Otherwise if regexp or wildcard token’s type is "asterisk",
+                    // then set regexp value to the full wildcard regexp value.
+                    if token.token_type == TokenType::Asterisk {
+                        FULL_WILDCARD_REGEXP_VALUE.into()
+                    }
+                    // Step 9. Otherwise set regexp value to regexp or wildcard token’s value.
+                    else {
+                        token.value.to_owned()
+                    }
+                },
+            }
+        };
+
+        // Step 10. Let type be "regexp".
+        let mut part_type = PartType::Regexp;
+
+        // Step 11. If regexp value is parser’s segment wildcard regexp:
+        if regexp_value == self.segment_wildcard_regexp {
+            // Step 11.1 Set type to "segment-wildcard".
+            part_type = PartType::SegmentWildcard;
+
+            // Step 11.2 Set regexp value to the empty string.
+            regexp_value.clear();
+        }
+        // Step 12. Otherwise if regexp value is the full wildcard regexp value:
+        else if regexp_value == FULL_WILDCARD_REGEXP_VALUE {
+            // Step 12.1 Set type to "full-wildcard".
+            part_type = PartType::FullWildcard;
+
+            // Step 12.2 Set regexp value to the empty string.
+            regexp_value.clear();
+        }
+
+        // Step 13. Let name be the empty string.
+        let mut name = String::new();
+
+        // Step 14. If name token is not null, then set name to name token’s value.
+        if let Some(name_token) = name_token {
+            name = name_token.value.to_owned();
+        }
+        // Step 15. Otherwise if regexp or wildcard token is not null:
+        else if regexp_or_wildcard_token.is_some() {
+            // Step 15.1 Set name to parser’s next numeric name, serialized.
+            name = self.next_numeric_name.to_string();
+
+            // Step 15.2 Increment parser’s next numeric name by 1.
+            self.next_numeric_name = self.next_numeric_name.wrapping_add(1);
+        }
+
+        // Step 16. If the result of running is a duplicate name given parser and name is true, then throw a TypeError.
+        if self.is_a_duplicate_name(&name) {
+            return Err(Error::Type(format!("Duplicate part name: {name:?}")));
+        }
+
+        // Step 17. Let encoded prefix be the result of running parser’s encoding callback given prefix.
+        let encoded_prefix = (self.encoding_callback)(prefix)?;
+
+        // Step 18. Let encoded suffix be the result of running parser’s encoding callback given suffix.
+        let encoded_suffix = (self.encoding_callback)(suffix)?;
+
+        // Step 19. Let part be a new part whose type is type, value is regexp value, modifier is modifier,
+        // name is name, prefix is encoded prefix, and suffix is encoded suffix.
+        let part = Part {
+            part_type,
+            value: regexp_value,
+            modifier,
+            name,
+            prefix: encoded_prefix,
+            suffix: encoded_suffix,
+        };
+
+        // Step 20. Append part to parser’s part list.
+        self.part_list.push(part);
+
+        Ok(())
+    }
+
+    // <https://urlpattern.spec.whatwg.org/#is-a-duplicate-name>
+    fn is_a_duplicate_name(&self, name: &str) -> bool {
+        // Step 1. For each part of parser’s part list:
+        for part in &self.part_list {
+            // Step 1.1 If part’s name is name, then return true.
+            if part.name == name {
+                return true;
+            }
+        }
+
+        // Step 2. Return false.
+        false
+    }
+
+    /// <https://urlpattern.spec.whatwg.org/#consume-text>
+    fn consume_text(&mut self) -> String {
+        // Step 1. Let result be the empty string.
+        let mut result = String::new();
+
+        // Step 2. While true:
+        loop {
+            // Step 2.1 Let token be the result of running try to consume a token given parser and "char".
+            let mut token = self.try_to_consume_a_token(TokenType::Char);
+
+            // Step 2.2 If token is null, then set token to the result of running
+            // try to consume a token given parser and "escaped-char".
+            if token.is_none() {
+                token = self.try_to_consume_a_token(TokenType::EscapedChar);
+            }
+
+            // Step 2.3 If token is null, then break.
+            let Some(token) = token else {
+                break;
+            };
+
+            // Step 2.4 Append token’s value to the end of result.
+            result.push_str(token.value);
+        }
+
+        result
+    }
+}