katex-rs 0.2.4

A Rust implementation of KaTeX - Fast math typesetting for anywhere, more than just the web.
Documentation 
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use crate::types::Mode;
use crate::{
    KatexContext, ParseError, Settings,
    macros::MacroContextInterface as _,
    parser::{
        Parser,
        parse_node::{ParseNode, ParseNodeTag},
    },
    types::{ParseErrorKind, Token},
};

/// Parses an expression using a Parser, then returns the parsed result.
pub fn parse_tree(
    ctx: &KatexContext,
    expr: &str,
    settings: &Settings,
) -> Result<Vec<ParseNode>, ParseError> {
    let mut parser = Parser::new(expr, settings, ctx);
    // Blank out any \df@tag to avoid spurious "Duplicate \tag" errors
    parser.gullet.macros_mut().purge("\\df@tag");
    let tree = parser.parse()?;
    // Prevent a color definition from persisting between calls to katex.render().
    parser.gullet.macros_mut().purge("\\current@color");
    parser.gullet.macros_mut().purge("\\color");
    // If the input used \tag, it will set the \df@tag macro to the tag.
    // In this case, we separately parse the tag and wrap the tree.
    if parser.gullet.macros().get("\\df@tag").is_some() {
        if !settings.display_mode {
            return Err(ParseError::new(ParseErrorKind::TagNotAllowedInInlineMode));
        }
        let tree = vec![ParseNode::Tag(ParseNodeTag {
            mode: Mode::Text,
            loc: None,
            body: tree,
            tag: parser.subparse(vec![Token::new("\\df@tag", None)])?,
        })];

        return Ok(tree);
    }

    Ok(tree)
}