Generic MathML Errors using Parser Lookahead (some endpoints updated)

[Adi-UA]

Changes

• Generic MathML Parser Error update:

  • Added tag level errors to generic_mathml.rs parser: <mi>, <mn>, <msup>, <msub>, <msqrt>, <mfrac>, <mrow>, <munder>, <mover>, <msubsup>, <mtext>, <mstyle>, <mspace>, <mo>.
  • /mathml/ast-graph endpoint now shows these errors.

• First Order ODE Parser Error update:

  • Updated ParseError messages using the context combinator, removing the previous macro usage.
  • The generic MathML errors were excluded as this parser uses interpreted_mathml.rs, which doesn't encounter those errors at the math_expression level.

• /pmml/equations-to-amr and /latex/equations-to-amr are passing on these errors. from skema-rs

Notes

• Lookahead Algorithm:

  • Solved the problem of adding tag level parse errors by implementing a lookahead in the parser.
  • In math_expression, instead of using alt for multiple branches of parsers, the following steps were adopted:
    1. Grab the content of the next tag.
    2. If it is an open tag, call the appropriate parser. If the parser fails, we can immediately stop execution with cut because of the lookahead knowledge.
    3. If the tag was a close tag, return an Error instead of a Failure. Failure cuts the execution, but returning an Error allows the parent combinator to continue using parsers on the remaining input.
  • This approach enables many0 and other combinators to work as expected. When we run out of things (like math expressions) for many0 to match (encountered a close tag), we return an Error, allowing the parent combinator to continue. But, as long as we know there is an expression to match (open tag), we can guarantee that if the internal parser (for <mi>, <mo>, etc.) fails, it was due to bad input.

Testing

• cargo test and cargo clippy passing.

[Free-Quarks]

LGTM!