use crate::prelude::*;
impl Runtime {
pub fn parse_by_induc_stmt(&mut self, tb: &mut TokenBlock) -> Result<Stmt, RuntimeError> {
tb.skip_token(INDUC)?;
let param = tb.advance()?;
tb.skip_token(FROM)?;
let induc_from = self.parse_obj(tb)?;
tb.skip_token(COLON)?;
if !tb.exceed_end_of_head() {
return Err(RuntimeError::new_parse_error_with_msg_position_previous_error(
"by induc: expected end of head".to_string(),
tb.line_file.clone(),
None,
));
}
let mut to_prove: Vec<ExistOrAndChainAtomicFact> = vec![];
for block in tb.body.iter_mut() {
to_prove.push(self.parse_exist_or_and_chain_atomic_fact(block)?);
}
Ok(ByInducStmt::new(to_prove, param, induc_from, tb.line_file.clone()).into())
}
}