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59 lines
2.1 KiB
59 lines
2.1 KiB
use sexp::Sexp;
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use crate::asm::data::Register;
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use crate::asm::error::CrsnError;
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use crate::asm::instr::{Flatten, Routine};
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use crate::asm::parse::{parse_instructions, ParserContext};
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use crate::asm::parse::arg_parser::TokenParser;
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use crate::asm::parse::parse_data::parse_reg_alias;
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use crate::asm::parse::sexp_expect::expect_string_atom;
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use crate::asm::patches::SexpIsA;
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use crate::builtin::parse::parse_routine_name;
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pub fn parse_routine(mut toki: impl Iterator<Item=Sexp> + Clone, pcx: &ParserContext) -> Result<Box<dyn Flatten>, CrsnError> {
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let name = expect_string_atom(toki.next())?;
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let mut name = parse_routine_name(name)?;
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let arg_tokens = TokenParser::new(toki.clone().take_while(|e| e.is_atom()).collect(), pcx);
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// If arity is explicitly given, then either no named argument must be provided,
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// or their count must match the arity. If no arity is given, then arity is determined
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// by the number of named arguments.
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if name.arity == 0 && arg_tokens.len() != 0 {
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name.arity = arg_tokens.len() as u8;
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} else if arg_tokens.len() != 0 && name.arity as usize != arg_tokens.len() {
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return Err(CrsnError::Parse(format!("arity mismatch in routine {}", name.name).into()));
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}
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let toki = toki.skip_while(|e| e.is_atom());
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{
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let mut pstate = pcx.state.borrow_mut();
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let old = std::mem::replace(&mut pstate.reg_aliases, Default::default());
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pstate.reg_alias_stack.push(old);
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for (n, tok) in arg_tokens.into_iter().enumerate() {
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let alias = parse_reg_alias(Some(tok))?;
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if pstate.constants.contains_key(&alias) {
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return Err(CrsnError::Parse(format!("Symbol \"{}\" already used for a constant.", alias).into()));
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}
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pstate.reg_aliases.insert(alias, Register::Arg(n as u8));
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}
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}
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let body = parse_instructions(toki, pcx)?;
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{
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let mut pstate = pcx.state.borrow_mut();
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let old = pstate.reg_alias_stack.pop().unwrap();
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pstate.reg_aliases = old;
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}
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return Ok(Box::new(Routine {
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name,
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body,
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}));
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}
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