Extract element utility fns to element_util.rs

Makes `interface.rs` file easier to navigate.

Also extracted `enable_logs` to `logs.rs`.

This is a refactoring that I've extracted from daisy#374,
where these functions are used by both the stateful
and the stateless interface and I wanted to avoid
any dependencies from `stateless_interface` on
`interface`.

Author: glebm

src/canonicalize.rs

@@ -4392,7 +4392,7 @@ mod canonicalize_tests {
 
     #[test]
     fn illegal_mathml_element() {
-		use crate::interface::*;
+		use crate::element_util::{get_element, trim_element};
         let test_str = "<math><foo><mi>f</mi></foo></math>";
         let package1 = &parser::parse(test_str).expect("Failed to parse test input");
 		let mathml = get_element(package1);
@@ -4495,7 +4495,7 @@ mod canonicalize_tests {
 
     #[test]
     fn mrow_with_intent_and_single_child() {
-		use crate::interface::*;
+		use crate::element_util::{get_element, trim_element};
 		use sxd_document::parser;
 		use crate::canonicalize::canonicalize;
 		// this forces initialization
@@ -4519,7 +4519,7 @@ mod canonicalize_tests {
     #[test]
     fn empty_mrow_with_intent() {
 		// we don't want to remove the mrow because the intent on the mi would reference itself
-		use crate::interface::*;
+		use crate::element_util::{get_element, trim_element};
 		use sxd_document::parser;
 		use crate::canonicalize::canonicalize;
 		// this forces initialization

src/chemistry.rs

@@ -1818,7 +1818,7 @@ mod chem_tests {
     fn parse_mathml_string<F>(test: &str, test_mathml: F) -> bool
             where F: Fn(Element) -> bool {
         use sxd_document::parser;
-        use crate::interface::{get_element, trim_element};
+        use crate::element_util::{get_element, trim_element};
 
         let new_package = parser::parse(&test);
         if let Err(e) = new_package {

src/element_util.rs

@@ -0,0 +1,326 @@
+use crate::canonicalize::{as_element, name};
+use crate::errors::*;
+use crate::logs::enable_logs;
+use crate::xpath_functions::{is_leaf, IsNode};
+use lazy_static::lazy_static;
+use regex::Regex;
+use sxd_document::{Package};
+use sxd_document::dom::*;
+
+pub fn get_element(package: &Package) -> Element {
+    enable_logs();
+    let doc = package.as_document();
+    let mut result = None;
+    for root_child in doc.root().children() {
+        if let ChildOfRoot::Element(e) = root_child {
+            assert!(result.is_none());
+            result = Some(e);
+        }
+    }
+    return result.unwrap();
+}
+
+/// returns Ok() if two Documents are equal or some info where they differ in the Err
+// Not really meant to be public -- used by tests in some packages
+#[allow(dead_code)]
+pub fn is_same_element(e1: Element, e2: Element) -> Result<()> {
+    enable_logs();
+    if name(e1) != name(e2) {
+        bail!("Names not the same: {}, {}", name(e1), name(e2));
+    }
+
+    // assume 'e' doesn't have element children until proven otherwise
+    // this means we keep Text children until we are proven they aren't needed
+    if e1.children().len() != e2.children().len() {
+        bail!(
+            "Children of {} have {} != {} children",
+            name(e1),
+            e1.children().len(),
+            e2.children().len()
+        );
+    }
+
+    if let Err(e) = attrs_are_same(e1.attributes(), e2.attributes()) {
+        bail!("In element {}, {}", name(e1), e);
+    }
+
+    for (i, (c1, c2)) in e1.children().iter().zip(e2.children().iter()).enumerate() {
+        match c1 {
+            ChildOfElement::Element(child1) => {
+                if let ChildOfElement::Element(child2) = c2 {
+                    is_same_element(*child1, *child2)?;
+                } else {
+                    bail!("{} child #{}, first is element, second is something else", name(e1), i);
+                }
+            }
+            ChildOfElement::Comment(com1) => {
+                if let ChildOfElement::Comment(com2) = c2 {
+                    if com1.text() != com2.text() {
+                        bail!("{} child #{} -- comment text differs", name(e1), i);
+                    }
+                } else {
+                    bail!("{} child #{}, first is comment, second is something else", name(e1), i);
+                }
+            }
+            ChildOfElement::ProcessingInstruction(p1) => {
+                if let ChildOfElement::ProcessingInstruction(p2) = c2 {
+                    if p1.target() != p2.target() || p1.value() != p2.value() {
+                        bail!("{} child #{} -- processing instruction differs", name(e1), i);
+                    }
+                } else {
+                    bail!(
+                        "{} child #{}, first is processing instruction, second is something else",
+                        name(e1),
+                        i
+                    );
+                }
+            }
+            ChildOfElement::Text(t1) => {
+                if let ChildOfElement::Text(t2) = c2 {
+                    if t1.text() != t2.text() {
+                        bail!("{} child #{} --  text differs", name(e1), i);
+                    }
+                } else {
+                    bail!("{} child #{}, first is text, second is something else", name(e1), i);
+                }
+            }
+        }
+    }
+    return Ok(());
+
+    /// compares attributes -- '==' didn't seems to work
+    fn attrs_are_same(attrs1: Vec<Attribute>, attrs2: Vec<Attribute>) -> Result<()> {
+        if attrs1.len() != attrs2.len() {
+            bail!("Attributes have different length: {:?} != {:?}", attrs1, attrs2);
+        }
+        // can't guarantee attrs are in the same order
+        for attr1 in attrs1 {
+            if let Some(found_attr2) = attrs2
+                .iter()
+                .find(|&attr2| attr1.name().local_part() == attr2.name().local_part())
+            {
+                if attr1.value() == found_attr2.value() {
+                    continue;
+                } else {
+                    bail!(
+                        "Attribute named {} has differing values:\n  '{}'\n  '{}'",
+                        attr1.name().local_part(),
+                        attr1.value(),
+                        found_attr2.value()
+                    );
+                }
+            } else {
+                bail!(
+                    "Attribute name {} not in [{}]",
+                    print_attr(&attr1),
+                    print_attrs(&attrs2)
+                );
+            }
+        }
+        return Ok(());
+
+        fn print_attr(attr: &Attribute) -> String {
+            return format!("@{}='{}'", attr.name().local_part(), attr.value());
+        }
+        fn print_attrs(attrs: &[Attribute]) -> String {
+            return attrs.iter().map(print_attr).collect::<Vec<String>>().join(", ");
+        }
+    }
+}
+
+// used for testing trim
+/// returns Ok() if two Documents are equal or some info where they differ in the Err
+#[allow(dead_code)]
+pub(crate) fn is_same_doc(doc1: &Document, doc2: &Document) -> Result<()> {
+    // assume 'e' doesn't have element children until proven otherwise
+    // this means we keep Text children until we are proven they aren't needed
+    if doc1.root().children().len() != doc2.root().children().len() {
+        bail!(
+            "Children of docs have {} != {} children",
+            doc1.root().children().len(),
+            doc2.root().children().len()
+        );
+    }
+
+    for (i, (c1, c2)) in doc1
+        .root()
+        .children()
+        .iter()
+        .zip(doc2.root().children().iter())
+        .enumerate()
+    {
+        match c1 {
+            ChildOfRoot::Element(e1) => {
+                if let ChildOfRoot::Element(e2) = c2 {
+                    is_same_element(*e1, *e2)?;
+                } else {
+                    bail!("child #{}, first is element, second is something else", i);
+                }
+            }
+            ChildOfRoot::Comment(com1) => {
+                if let ChildOfRoot::Comment(com2) = c2 {
+                    if com1.text() != com2.text() {
+                        bail!("child #{} -- comment text differs", i);
+                    }
+                } else {
+                    bail!("child #{}, first is comment, second is something else", i);
+                }
+            }
+            ChildOfRoot::ProcessingInstruction(p1) => {
+                if let ChildOfRoot::ProcessingInstruction(p2) = c2 {
+                    if p1.target() != p2.target() || p1.value() != p2.value() {
+                        bail!("child #{} -- processing instruction differs", i);
+                    }
+                } else {
+                    bail!(
+                        "child #{}, first is processing instruction, second is something else",
+                        i
+                    );
+                }
+            }
+        }
+    }
+    return Ok(());
+}
+
+/// Not really meant to be public -- used by tests in some packages
+pub fn trim_element(e: Element, allow_structure_in_leaves: bool) {
+    // "<mtext>this is text</mtext" results in 3 text children
+    // these are combined into one child as it makes code downstream simpler
+
+    // space, tab, newline, carriage return all get collapsed to a single space
+    const WHITESPACE: &[char] = &[' ', '\u{0009}', '\u{000A}', '\u{000D}'];
+    lazy_static! {
+        static ref WHITESPACE_MATCH: Regex = Regex::new(r#"[ \u{0009}\u{000A}\u{000D}]+"#).unwrap();
+    }
+
+    if is_leaf(e) && (!allow_structure_in_leaves || IsNode::is_mathml(e)) {
+        // Assume it is HTML inside of the leaf -- turn the HTML into a string
+        make_leaf_element(e);
+        return;
+    }
+
+    let mut single_text = "".to_string();
+    for child in e.children() {
+        match child {
+            ChildOfElement::Element(c) => {
+                trim_element(c, allow_structure_in_leaves);
+            }
+            ChildOfElement::Text(t) => {
+                single_text += t.text();
+                e.remove_child(child);
+            }
+            _ => {
+                e.remove_child(child);
+            }
+        }
+    }
+
+    // CSS considers only space, tab, linefeed, and carriage return as collapsable whitespace
+    if !(is_leaf(e) || name(e) == "intent-literal" || single_text.is_empty()) {
+        // intent-literal comes from testing intent
+        // FIX: we have a problem -- what should happen???
+        // FIX: For now, just keep the children and ignore the text and log an error -- shouldn't panic/crash
+        if !single_text.trim_matches(WHITESPACE).is_empty() {
+            error!(
+                "trim_element: both element and textual children which shouldn't happen -- ignoring text '{}'",
+                single_text
+            );
+        }
+        return;
+    }
+    if e.children().is_empty() && !single_text.is_empty() {
+        // debug!("Combining text in {}: '{}' -> '{}'", e.name().local_part(), single_text, trimmed_text);
+        e.set_text(&WHITESPACE_MATCH.replace_all(&single_text, " "));
+    }
+
+    fn make_leaf_element(mathml_leaf: Element) {
+        // MathML leaves like <mn> really shouldn't have non-textual content, but you could have embedded HTML
+        // Here, we take convert them to leaves by grabbing up all the text and making that the content
+        // Potentially, we leave them and let (default) rules do something, but it makes other parts of the code
+        //   messier because checking the text of a leaf becomes Option<&str> rather than just &str
+        let children = mathml_leaf.children();
+        if children.is_empty() {
+            return;
+        }
+
+        // gather up the text
+        let mut text = "".to_string();
+        for child in children {
+            let child_text = match child {
+                ChildOfElement::Element(child) => {
+                    if name(child) == "mglyph" {
+                        child.attribute_value("alt").unwrap_or("").to_string()
+                    } else {
+                        gather_text(child)
+                    }
+                }
+                ChildOfElement::Text(t) => {
+                    // debug!("ChildOfElement::Text: '{}'", t.text());
+                    t.text().to_string()
+                }
+                _ => "".to_string(),
+            };
+            if !child_text.is_empty() {
+                text += &child_text;
+            }
+        }
+
+        // get rid of the old children and replace with the text we just built
+        mathml_leaf.clear_children();
+        mathml_leaf.set_text(WHITESPACE_MATCH.replace_all(&text, " ").trim_matches(WHITESPACE));
+        // debug!("make_leaf_element: text is '{}'", crate::canonicalize::as_text(mathml_leaf));
+
+        /// gather up all the contents of the element and return them with a leading space
+        fn gather_text(html: Element) -> String {
+            let mut text = "".to_string(); // since we are throwing out the element tag, add a space between the contents
+            for child in html.children() {
+                match child {
+                    ChildOfElement::Element(child) => {
+                        text += &gather_text(child);
+                    }
+                    ChildOfElement::Text(t) => text += t.text(),
+                    _ => (),
+                }
+            }
+            // debug!("gather_text: '{}'", text);
+            return text;
+        }
+    }
+}
+
+pub(crate) fn add_ids(mathml: Element) -> Element {
+    use std::time::SystemTime;
+    let time = if cfg!(target_family = "wasm") {
+        fastrand::usize(..)
+    } else {
+        SystemTime::now()
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .unwrap()
+            .as_millis() as usize
+    };
+    let time_part = radix_fmt::radix(time, 36).to_string();
+    let random_part = radix_fmt::radix(fastrand::u32(..), 36).to_string();
+    let prefix = "M".to_string() + &time_part[time_part.len() - 3..] + &random_part[random_part.len() - 4..] + "-"; // begin with letter
+    add_ids_to_all(mathml, &prefix, 0);
+    return mathml;
+
+    fn add_ids_to_all(mathml: Element, id_prefix: &str, count: usize) -> usize {
+        let mut count = count;
+        if mathml.attribute("id").is_none() {
+            mathml.set_attribute_value("id", (id_prefix.to_string() + &count.to_string()).as_str());
+            mathml.set_attribute_value("data-id-added", "true");
+            count += 1;
+        };
+
+        if crate::xpath_functions::is_leaf(mathml) {
+            return count;
+        }
+
+        for child in mathml.children() {
+            let child = as_element(child);
+            count = add_ids_to_all(child, id_prefix, count);
+        }
+        return count;
+    }
+}

src/infer_intent.rs

@@ -611,7 +611,7 @@ mod tests {
 
 
     fn test_intent(mathml: &str, target: &str, intent_error_recovery: &str) -> bool {
-		use crate::interface::*;
+		use crate::{interface::*, element_util::*};
 		// this forces initialization
         crate::interface::set_rules_dir(super::super::abs_rules_dir_path()).unwrap();
         // crate::speech::SpeechRules::initialize_all_rules().unwrap();