Function build_function

src/infer_intent.rs:300–326

Build a function 'f(...)' where '...' can be empty Also handles nested functions like f(...)(...) Start state: at '(' End state: after ')'

(
            function_name: Element<'m>,
            rules_with_context: &'r mut SpeechRulesWithContext<'c,'s,'m>,
            lex_state: &mut LexState<'b>,
            mathml: Element<'c>)

/// 
/// End state: after ')'
fn build_function<'b, 'r, 'c, 's:'c, 'm:'c>(
            function_name: Element<'m>,
            rules_with_context: &'r mut SpeechRulesWithContext<'c,'s,'m>,
            lex_state: &mut LexState<'b>,
            mathml: Element<'c>) -> Result<Element<'m>> {
    // debug!("  start build_function: name: {}, state: {}", name(&function_name), lex_state);
    // application := intent '(' arguments? S ')'  where 'function_name' is 'intent'
    assert!(lex_state.is_terminal("("));
    let mut function = function_name;
    while lex_state.is_terminal("(") {
        lex_state.get_next()?;
        if lex_state.is_terminal(")") {
            // grammar requires at least one argument
            bail!("Illegal 'intent' syntax: missing argument for intent name '{}'", name(&function_name));
        }
        let children = build_arguments(rules_with_context, lex_state, mathml)?;
        function = lift_function_name(rules_with_context.get_document(), function, children);

        if !lex_state.is_terminal(")") {
            bail!("Illegal 'intent' syntax: missing ')' for intent name '{}'", name(&function_name));
        }
        lex_state.get_next()?;
    }
    // debug!("  end build_function/# children: {}, #state: {}  ..[bfa] function name: {}",
    //     function.children().len(), lex_state, mml_to_string(&function));
    return Ok(function);
}

// process all the args of a function
// Start state: after '('