reuse reveal_cloze_text() for LaTeX cloze expansion

proto/backend.proto

@@ -18,6 +18,7 @@ message BackendInput {
         int64 local_minutes_west = 22;
         string strip_av_tags = 23;
         ExtractAVTagsIn extract_av_tags = 24;
+        string expand_clozes_to_reveal_latex = 25;
     }
 }
 
@@ -32,6 +33,7 @@ message BackendOutput {
         sint32 local_minutes_west = 22;
         string strip_av_tags = 23;
         ExtractAVTagsOut extract_av_tags = 24;
+        string expand_clozes_to_reveal_latex = 25;
 
         BackendError error = 2047;
     }

pylib/anki/media.py

@@ -1,5 +1,8 @@
 # Copyright: Ankitects Pty Ltd and contributors
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+
+from __future__ import annotations
+
 import io
 import json
 import os
@@ -14,11 +17,11 @@ import urllib.request
 import zipfile
 from typing import Any, Callable, List, Optional, Tuple, Union
 
+import anki
 from anki.consts import *
 from anki.db import DB, DBError
 from anki.lang import _
 from anki.latex import render_latex
-from anki.template import expand_clozes
 from anki.utils import checksum, isMac, isWin
 
 
@@ -34,7 +37,7 @@ class MediaManager:
     regexps = soundRegexps + imgRegexps
     db: Optional[DB]
 
-    def __init__(self, col, server: bool) -> None:
+    def __init__(self, col: anki.storage._Collection, server: bool) -> None:
         self.col = col
         if server:
             self._dir = None
@@ -213,23 +216,21 @@ create table meta (dirMod int, lastUsn int); insert into meta values (0, 0);
     ) -> List[str]:
         l = []
         model = self.col.models.get(mid)
-        strings: List[str] = []
         if model["type"] == MODEL_CLOZE and "{{c" in string:
             # if the field has clozes in it, we'll need to expand the
             # possibilities so we can render latex
-            strings = expand_clozes(string)
+            strings = self.col.backend.expand_clozes_to_reveal_latex(string)
         else:
-            strings = [string]
-        for string in strings:
-            # handle latex
-            string = render_latex(string, model, self.col)
-            # extract filenames
-            for reg in self.regexps:
-                for match in re.finditer(reg, string):
-                    fname = match.group("fname")
-                    isLocal = not re.match("(https?|ftp)://", fname.lower())
-                    if isLocal or includeRemote:
-                        l.append(fname)
+            strings = string
+        # handle latex
+        string = render_latex(string, model, self.col)
+        # extract filenames
+        for reg in self.regexps:
+            for match in re.finditer(reg, string):
+                fname = match.group("fname")
+                isLocal = not re.match("(https?|ftp)://", fname.lower())
+                if isLocal or includeRemote:
+                    l.append(fname)
         return l
 
     def transformNames(self, txt: str, func: Callable) -> Any:

pylib/anki/rsbackend.py

@@ -1,6 +1,7 @@
 # Copyright: Ankitects Pty Ltd and contributors
 # License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 # pylint: skip-file
+
 from dataclasses import dataclass
 from typing import Dict, List, Tuple, Union
 
@@ -175,3 +176,8 @@ class RustBackend:
         native_tags = list(map(av_tag_to_native, out.av_tags))
 
         return out.text, native_tags
+
+    def expand_clozes_to_reveal_latex(self, text: str) -> str:
+        return self._run_command(
+            pb.BackendInput(expand_clozes_to_reveal_latex=text)
+        ).expand_clozes_to_reveal_latex

pylib/anki/template.py

@@ -28,7 +28,6 @@ template_legacy.py file, using the legacy addHook() system.
 
 from __future__ import annotations
 
-import re
 from dataclasses import dataclass
 from typing import Any, Dict, List, Optional, Tuple
 
@@ -221,44 +220,3 @@ def apply_custom_filters(
 
             res += field_text
     return res
-
-
-# Cloze handling
-##########################################################################
-
-# Matches a {{c123::clozed-out text::hint}} Cloze deletion, case-insensitively.
-# The regex should be interpolated with a regex number and creates the following
-# named groups:
-#   - tag: The lowercase or uppercase 'c' letter opening the Cloze.
-#          The c/C difference is only relevant to the legacy code.
-#   - content: Clozed-out content.
-#   - hint: Cloze hint, if provided.
-clozeReg = r"(?si)\{\{(?P<tag>c)%s::(?P<content>.*?)(::(?P<hint>.*?))?\}\}"
-
-# Constants referring to group names within clozeReg.
-CLOZE_REGEX_MATCH_GROUP_TAG = "tag"
-CLOZE_REGEX_MATCH_GROUP_CONTENT = "content"
-CLOZE_REGEX_MATCH_GROUP_HINT = "hint"
-
-# used by the media check functionality
-def expand_clozes(string: str) -> List[str]:
-    "Render all clozes in string."
-    ords = set(re.findall(r"{{c(\d+)::.+?}}", string))
-    strings = []
-
-    def qrepl(m):
-        if m.group(CLOZE_REGEX_MATCH_GROUP_HINT):
-            return "[%s]" % m.group(CLOZE_REGEX_MATCH_GROUP_HINT)
-        else:
-            return "[...]"
-
-    def arepl(m):
-        return m.group(CLOZE_REGEX_MATCH_GROUP_CONTENT)
-
-    for ord in ords:
-        s = re.sub(clozeReg % ord, qrepl, string)
-        s = re.sub(clozeReg % ".+?", arepl, s)
-        strings.append(s)
-    strings.append(re.sub(clozeReg % ".+?", arepl, string))
-
-    return strings

rslib/src/backend.rs

@@ -4,6 +4,7 @@
 use crate::backend_proto as pt;
 use crate::backend_proto::backend_input::Value;
 use crate::backend_proto::RenderedTemplateReplacement;
+use crate::cloze::expand_clozes_to_reveal_latex;
 use crate::err::{AnkiError, Result};
 use crate::sched::{local_minutes_west_for_stamp, sched_timing_today};
 use crate::template::{
@@ -101,6 +102,9 @@ impl Backend {
             }
             Value::StripAvTags(text) => OValue::StripAvTags(strip_av_tags(&text).into()),
             Value::ExtractAvTags(input) => OValue::ExtractAvTags(self.extract_av_tags(input)),
+            Value::ExpandClozesToRevealLatex(input) => {
+                OValue::ExpandClozesToRevealLatex(expand_clozes_to_reveal_latex(&input))
+            }
         })
     }
 

rslib/src/cloze.rs

@@ -2,7 +2,7 @@
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
 use crate::template::RenderContext;
-use crate::text::strip_html;
+use crate::text::{contains_latex, strip_html};
 use lazy_static::lazy_static;
 use regex::Captures;
 use regex::Regex;
@@ -91,6 +91,23 @@ pub fn reveal_cloze_text(text: &str, cloze_ord: u16, question: bool) -> Cow<str>
     }
 }
 
+/// If text contains any LaTeX tags, render the front and back
+/// of each cloze deletion so that LaTeX can be generated. If
+/// no LaTeX is found, returns an empty string.
+pub fn expand_clozes_to_reveal_latex(text: &str) -> String {
+    if !contains_latex(text) {
+        return "".into();
+    }
+    let ords = cloze_numbers_in_string(text);
+    let mut buf = String::new();
+    for ord in ords {
+        buf += reveal_cloze_text(text, ord, true).as_ref();
+        buf += reveal_cloze_text(text, ord, false).as_ref();
+    }
+
+    buf
+}
+
 pub fn cloze_numbers_in_string(html: &str) -> HashSet<u16> {
     let mut hash = HashSet::with_capacity(4);
     for cap in CLOZE.captures_iter(html) {
@@ -122,7 +139,8 @@ pub(crate) fn cloze_filter<'a>(text: &'a str, context: &RenderContext) -> Cow<'a
 
 #[cfg(test)]
 mod test {
-    use crate::cloze::cloze_numbers_in_string;
+    use crate::cloze::{cloze_numbers_in_string, expand_clozes_to_reveal_latex};
+    use crate::text::strip_html;
     use std::collections::HashSet;
 
     #[test]
@@ -135,5 +153,16 @@ mod test {
             cloze_numbers_in_string("{{c2::te}}{{c1::s}}t{{"),
             vec![1, 2].into_iter().collect::<HashSet<u16>>()
         );
+
+        assert_eq!(
+            expand_clozes_to_reveal_latex("{{c1::foo}} {{c2::bar::baz}}"),
+            "".to_string()
+        );
+
+        let expanded = expand_clozes_to_reveal_latex("[latex]{{c1::foo}} {{c2::bar::baz}}[/latex]");
+        let expanded = strip_html(expanded.as_ref());
+        assert!(expanded.contains("foo [baz]"));
+        assert!(expanded.contains("[...] bar"));
+        assert!(expanded.contains("foo bar"));
     }
 }

rslib/src/text.rs

@@ -44,6 +44,15 @@ lazy_static! {
                 (.*?)           # 3 - field text
             \[/anki:tts\]
             "#).unwrap();
+
+    static ref LATEX: Regex = Regex::new(
+        r#"(?xsi)
+            \[latex\](.+?)\[/latex\]     # 1 - standard latex
+            |
+            \[\$\](.+?)\[/\$\]           # 2 - inline math
+            |
+            \[\$\$\](.+?)\[/\$\$\]       # 3 - math environment
+            "#).unwrap();    
 }
 
 pub fn strip_html(html: &str) -> Cow<str> {
@@ -143,6 +152,10 @@ pub fn strip_html_preserving_image_filenames(html: &str) -> Cow<str> {
     without_html.into_owned().into()
 }
 
+pub(crate) fn contains_latex(text: &str) -> bool {
+    LATEX.is_match(text)
+}
+
 #[cfg(test)]
 mod test {
     use crate::text::{