Remove old reduced_ast, eval
This commit is contained in:
Greg Shuflin
parent
47ff6b3cb5
commit
0808bcbc87
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@ -1,444 +0,0 @@
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use std::rc::Rc;
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use std::fmt::Write;
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use std::io;
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use crate::util::ScopeStack;
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use crate::reduced_ast::{BoundVars, ReducedAST, Stmt, Expr, Lit, Func, Alternative, Pattern};
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use crate::builtin::Builtin;
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mod test;
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pub struct State<'a> {
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values: ScopeStack<'a, Rc<String>, ValueEntry>,
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}
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impl<'a> State<'a> {
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pub fn new() -> State<'a> {
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let values = ScopeStack::new(Some("global".to_string()));
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State { values }
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}
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#[allow(clippy::ptr_arg)]
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fn new_frame(&'a self, items: &'a [Node], bound_vars: &BoundVars) -> State<'a> {
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let mut inner_state = State {
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values: self.values.new_scope(None),
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};
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for (bound_var, val) in bound_vars.iter().zip(items.iter()) {
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if let Some(bv) = bound_var.as_ref() {
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inner_state.values.insert(bv.clone(), ValueEntry::Binding { constant: true, val: val.clone() });
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}
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}
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inner_state
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}
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}
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#[derive(Debug, Clone)]
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enum Node {
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Expr(Expr),
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PrimObject {
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name: Rc<String>,
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tag: usize,
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items: Vec<Node>,
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},
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PrimTuple {
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items: Vec<Node>
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}
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}
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fn paren_wrapped_vec(terms: impl Iterator<Item=String>) -> String {
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let mut buf = String::new();
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write!(buf, "(").unwrap();
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for term in terms.map(Some).intersperse(None) {
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match term {
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Some(e) => write!(buf, "{}", e).unwrap(),
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None => write!(buf, ", ").unwrap(),
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};
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}
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write!(buf, ")").unwrap();
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buf
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}
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impl Node {
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fn to_repl(&self) -> String {
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match self {
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Node::Expr(e) => e.to_repl(),
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Node::PrimObject { name, items, .. } if items.is_empty() => format!("{}", name),
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Node::PrimObject { name, items, .. } => format!("{}{}", name, paren_wrapped_vec(items.iter().map(|x| x.to_repl()))),
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Node::PrimTuple { items } => paren_wrapped_vec(items.iter().map(|x| x.to_repl())),
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}
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}
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fn is_true(&self) -> bool {
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matches!(self, Node::Expr(Expr::Lit(crate::reduced_ast::Lit::Bool(true))))
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}
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}
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#[derive(Debug)]
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enum ValueEntry {
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Binding {
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constant: bool,
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val: /*FullyEvaluatedExpr*/ Node, //TODO make this use a subtype to represent fully evaluatedness
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}
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}
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type EvalResult<T> = Result<T, String>;
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impl Expr {
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#[allow(clippy::wrong_self_convention)]
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fn to_node(self) -> Node {
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Node::Expr(self)
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}
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fn to_repl(&self) -> String {
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use self::Lit::*;
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use self::Func::*;
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match self {
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Expr::Lit(ref l) => match l {
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Nat(n) => format!("{}", n),
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Int(i) => format!("{}", i),
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Float(f) => format!("{}", f),
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Bool(b) => format!("{}", b),
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StringLit(s) => format!("\"{}\"", s),
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},
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Expr::Func(f) => match f {
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BuiltIn(builtin) => format!("<built-in function '{:?}'>", builtin),
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UserDefined { name: None, .. } => "<function>".to_string(),
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UserDefined { name: Some(name), .. } => format!("<function '{}'>", name),
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},
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Expr::Constructor { type_name, arity, .. } => {
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format!("<constructor for `{}` arity {}>", type_name, arity)
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},
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Expr::Tuple(exprs) => paren_wrapped_vec(exprs.iter().map(|x| x.to_repl())),
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_ => format!("{:?}", self),
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}
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}
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fn replace_conditional_target_sigil(self, replacement: &Expr) -> Expr {
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use self::Expr::*;
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match self {
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ConditionalTargetSigilValue => replacement.clone(),
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Lit(_) | Func(_) | Sym(_) | Constructor { .. } |
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CaseMatch { .. } | UnimplementedSigilValue | ReductionError(_) => self,
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Tuple(exprs) => Tuple(exprs.into_iter().map(|e| e.replace_conditional_target_sigil(replacement)).collect()),
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Call { f, args } => {
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let new_args = args.into_iter().map(|e| e.replace_conditional_target_sigil(replacement)).collect();
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Call { f, args: new_args }
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},
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Conditional { .. } => panic!("Dunno if I need this, but if so implement"),
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Assign { .. } => panic!("I'm pretty sure I don't need this"),
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}
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}
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}
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impl<'a> State<'a> {
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pub fn evaluate(&mut self, ast: ReducedAST, repl: bool) -> Vec<Result<String, String>> {
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let mut acc = vec![];
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// handle prebindings
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for statement in ast.0.iter() {
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self.prebinding(statement);
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}
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for statement in ast.0 {
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match self.statement(statement) {
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Ok(Some(ref output)) if repl => {
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acc.push(Ok(output.to_repl()))
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},
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Ok(_) => (),
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Err(error) => {
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acc.push(Err(format!("Runtime error: {}", error)));
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return acc;
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},
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}
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}
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acc
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}
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fn prebinding(&mut self, stmt: &Stmt) {
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match stmt {
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Stmt::PreBinding { name, func } => {
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let v_entry = ValueEntry::Binding { constant: true, val: Node::Expr(Expr::Func(func.clone())) };
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self.values.insert(name.clone(), v_entry);
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},
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Stmt::Expr(_expr) => {
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//TODO have this support things like nested function defs
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},
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_ => ()
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}
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}
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fn statement(&mut self, stmt: Stmt) -> EvalResult<Option<Node>> {
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match stmt {
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Stmt::Binding { name, constant, expr } => {
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let val = self.expression(Node::Expr(expr))?;
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self.values.insert(name, ValueEntry::Binding { constant, val });
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Ok(None)
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},
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Stmt::Expr(expr) => Ok(Some(self.expression(expr.to_node())?)),
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Stmt::PreBinding {..} | Stmt::Noop => Ok(None),
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}
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}
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fn block(&mut self, stmts: Vec<Stmt>) -> EvalResult<Node> {
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let mut ret = None;
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for stmt in stmts {
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ret = self.statement(stmt)?;
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}
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Ok(ret.unwrap_or_else(|| Node::Expr(Expr::unit())))
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}
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fn expression(&mut self, node: Node) -> EvalResult<Node> {
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use self::Expr::*;
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match node {
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t @ Node::PrimTuple { .. } => Ok(t),
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obj @ Node::PrimObject { .. } => Ok(obj),
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Node::Expr(expr) => match expr {
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literal @ Lit(_) => Ok(Node::Expr(literal)),
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Call { box f, args } => self.call_expression(f, args),
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Sym(name) => Ok(match self.values.lookup(&name) {
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Some(ValueEntry::Binding { val, .. }) => val.clone(),
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None => return Err(format!("Could not look up symbol {}", name))
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}),
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Constructor { arity, ref name, tag, .. } if arity == 0 => Ok(Node::PrimObject { name: name.clone(), tag, items: vec![] }),
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constructor @ Constructor { .. } => Ok(Node::Expr(constructor)),
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func @ Func(_) => Ok(Node::Expr(func)),
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Tuple(exprs) => {
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let nodes = exprs.into_iter().map(|expr| self.expression(Node::Expr(expr))).collect::<Result<Vec<Node>,_>>()?;
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Ok(Node::PrimTuple { items: nodes })
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},
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Conditional { box cond, then_clause, else_clause } => self.conditional(cond, then_clause, else_clause),
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Assign { box val, box expr } => self.assign_expression(val, expr),
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CaseMatch { box cond, alternatives } => self.case_match_expression(cond, alternatives),
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ConditionalTargetSigilValue => Ok(Node::Expr(ConditionalTargetSigilValue)),
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UnimplementedSigilValue => Err("Sigil value eval not implemented".to_string()),
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ReductionError(err) => Err(format!("Reduction error: {}", err)),
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}
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}
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}
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fn call_expression(&mut self, f: Expr, args: Vec<Expr>) -> EvalResult<Node> {
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use self::Expr::*;
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match self.expression(Node::Expr(f))? {
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Node::Expr(Constructor { type_name, name, tag, arity }) => self.apply_data_constructor(type_name, name, tag, arity, args),
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Node::Expr(Func(f)) => self.apply_function(f, args),
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other => return Err(format!("Tried to call {:?} which is not a function or data constructor", other)),
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}
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}
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fn apply_data_constructor(&mut self, _type_name: Rc<String>, name: Rc<String>, tag: usize, arity: usize, args: Vec<Expr>) -> EvalResult<Node> {
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if arity != args.len() {
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return Err(format!("Data constructor {} requires {} arg(s)", name, arity));
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}
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let evaled_args = args.into_iter().map(|expr| self.expression(Node::Expr(expr))).collect::<Result<Vec<Node>,_>>()?;
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//let evaled_args = vec![];
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Ok(Node::PrimObject {
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name,
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items: evaled_args,
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tag
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})
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}
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fn apply_function(&mut self, f: Func, args: Vec<Expr>) -> EvalResult<Node> {
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match f {
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Func::BuiltIn(builtin) => Ok(self.apply_builtin(builtin, args)?),
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Func::UserDefined { params, body, name } => {
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if params.len() != args.len() {
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return Err(format!("calling a {}-argument function with {} args", params.len(), args.len()))
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}
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let mut func_state = State {
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values: self.values.new_scope(name.map(|n| format!("{}", n))),
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};
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for (param, val) in params.into_iter().zip(args.into_iter()) {
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let val = func_state.expression(Node::Expr(val))?;
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func_state.values.insert(param, ValueEntry::Binding { constant: true, val });
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}
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// TODO figure out function return semantics
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func_state.block(body)
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}
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}
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}
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fn apply_builtin(&mut self, builtin: Builtin, args: Vec<Expr>) -> EvalResult<Node> {
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use self::Expr::*;
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use self::Lit::*;
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use Builtin::*;
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let evaled_args: Result<Vec<Node>, String> = args.into_iter().map(|arg| self.expression(arg.to_node()))
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.collect();
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let evaled_args = evaled_args?;
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Ok(match (builtin, evaled_args.as_slice()) {
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(FieldAccess, &[Node::PrimObject { .. }]) => {
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//TODO implement field access
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unimplemented!()
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},
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(binop, &[Node::Expr(ref lhs), Node::Expr(ref rhs)]) => match (binop, lhs, rhs) {
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/* binops */
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(Add, Lit(Nat(l)), Lit(Nat(r))) => Lit(Nat(l + r)),
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(Concatenate, Lit(StringLit(ref s1)), Lit(StringLit(ref s2))) => Lit(StringLit(Rc::new(format!("{}{}", s1, s2)))),
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(Subtract, Lit(Nat(l)), Lit(Nat(r))) => Lit(Nat(l - r)),
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(Multiply, Lit(Nat(l)), Lit(Nat(r))) => Lit(Nat(l * r)),
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(Divide, Lit(Nat(l)), Lit(Nat(r))) => Lit(Float((*l as f64)/ (*r as f64))),
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(Quotient, Lit(Nat(l)), Lit(Nat(r))) => if *r == 0 {
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return Err("Divide-by-zero error".to_string());
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} else {
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Lit(Nat(l / r))
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},
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(Modulo, Lit(Nat(l)), Lit(Nat(r))) => Lit(Nat(l % r)),
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(Exponentiation, Lit(Nat(l)), Lit(Nat(r))) => Lit(Nat(l ^ r)),
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(BitwiseAnd, Lit(Nat(l)), Lit(Nat(r))) => Lit(Nat(l & r)),
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(BitwiseOr, Lit(Nat(l)), Lit(Nat(r))) => Lit(Nat(l | r)),
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/* comparisons */
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(Equality, Lit(Nat(l)), Lit(Nat(r))) => Lit(Bool(l == r)),
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(Equality, Lit(Int(l)), Lit(Int(r))) => Lit(Bool(l == r)),
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(Equality, Lit(Float(l)), Lit(Float(r))) => Lit(Bool(l == r)),
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(Equality, Lit(Bool(l)), Lit(Bool(r))) => Lit(Bool(l == r)),
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(Equality, Lit(StringLit(ref l)), Lit(StringLit(ref r))) => Lit(Bool(l == r)),
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(LessThan, Lit(Nat(l)), Lit(Nat(r))) => Lit(Bool(l < r)),
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(LessThan, Lit(Int(l)), Lit(Int(r))) => Lit(Bool(l < r)),
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(LessThan, Lit(Float(l)), Lit(Float(r))) => Lit(Bool(l < r)),
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(LessThanOrEqual, Lit(Nat(l)), Lit(Nat(r))) => Lit(Bool(l <= r)),
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(LessThanOrEqual, Lit(Int(l)), Lit(Int(r))) => Lit(Bool(l <= r)),
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(LessThanOrEqual, Lit(Float(l)), Lit(Float(r))) => Lit(Bool(l <= r)),
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(GreaterThan, Lit(Nat(l)), Lit(Nat(r))) => Lit(Bool(l > r)),
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(GreaterThan, Lit(Int(l)), Lit(Int(r))) => Lit(Bool(l > r)),
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(GreaterThan, Lit(Float(l)), Lit(Float(r))) => Lit(Bool(l > r)),
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(GreaterThanOrEqual, Lit(Nat(l)), Lit(Nat(r))) => Lit(Bool(l >= r)),
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(GreaterThanOrEqual, Lit(Int(l)), Lit(Int(r))) => Lit(Bool(l >= r)),
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(GreaterThanOrEqual, Lit(Float(l)), Lit(Float(r))) => Lit(Bool(l >= r)),
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_ => return Err("No valid binop".to_string())
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}.to_node(),
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(prefix, &[Node::Expr(ref arg)]) => match (prefix, arg) {
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(BooleanNot, Lit(Bool(true))) => Lit(Bool(false)),
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(BooleanNot, Lit(Bool(false))) => Lit(Bool(true)),
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(Negate, Lit(Nat(n))) => Lit(Int(-(*n as i64))),
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(Negate, Lit(Int(n))) => Lit(Int(-(*n as i64))),
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(Increment, Lit(Int(n))) => Lit(Int(*n)),
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(Increment, Lit(Nat(n))) => Lit(Nat(*n)),
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_ => return Err("No valid prefix op".to_string())
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}.to_node(),
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/* builtin functions */
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(IOPrint, &[ref anything]) => {
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print!("{}", anything.to_repl());
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Expr::unit().to_node()
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},
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(IOPrintLn, &[ref anything]) => {
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println!("{}", anything.to_repl());
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Expr::unit().to_node()
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},
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(IOGetLine, &[]) => {
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let mut buf = String::new();
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io::stdin().read_line(&mut buf).expect("Error readling line in 'getline'");
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Lit(StringLit(Rc::new(buf.trim().to_string()))).to_node()
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},
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(x, args) => return Err(format!("bad or unimplemented builtin {:?} | {:?}", x, args)),
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})
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}
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fn conditional(&mut self, cond: Expr, then_clause: Vec<Stmt>, else_clause: Vec<Stmt>) -> EvalResult<Node> {
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let cond = self.expression(Node::Expr(cond))?;
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Ok(match cond {
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Node::Expr(Expr::Lit(Lit::Bool(true))) => self.block(then_clause)?,
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Node::Expr(Expr::Lit(Lit::Bool(false))) => self.block(else_clause)?,
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_ => return Err("Conditional with non-boolean condition".to_string())
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})
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}
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fn assign_expression(&mut self, val: Expr, expr: Expr) -> EvalResult<Node> {
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let name = match val {
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Expr::Sym(name) => name,
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_ => return Err("Trying to assign to a non-value".to_string()),
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};
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let constant = match self.values.lookup(&name) {
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None => return Err(format!("Constant {} is undefined", name)),
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Some(ValueEntry::Binding { constant, .. }) => *constant,
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};
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if constant {
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return Err(format!("trying to update {}, a non-mutable binding", name));
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}
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let val = self.expression(Node::Expr(expr))?;
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self.values.insert(name, ValueEntry::Binding { constant: false, val });
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Ok(Node::Expr(Expr::unit()))
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}
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fn guard_passes(&mut self, guard: &Option<Expr>, cond: &Node) -> EvalResult<bool> {
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if let Some(ref guard_expr) = guard {
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let guard_expr = match cond {
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Node::Expr(ref e) => guard_expr.clone().replace_conditional_target_sigil(e),
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_ => guard_expr.clone()
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};
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Ok(self.expression(guard_expr.to_node())?.is_true())
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} else {
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Ok(true)
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}
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}
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fn case_match_expression(&mut self, cond: Expr, alternatives: Vec<Alternative>) -> EvalResult<Node> {
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//TODO need to handle recursive subpatterns
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let all_subpatterns_pass = |state: &mut State, subpatterns: &Vec<Option<Subpattern>>, items: &Vec<Node>| -> EvalResult<bool> {
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if subpatterns.is_empty() {
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return Ok(true)
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}
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if items.len() != subpatterns.len() {
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return Err(format!("Subpattern length isn't correct items {} subpatterns {}", items.len(), subpatterns.len()));
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}
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for (maybe_subp, cond) in subpatterns.iter().zip(items.iter()) {
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if let Some(subp) = maybe_subp {
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if !state.guard_passes(&subp.guard, cond)? {
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return Ok(false)
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}
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}
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}
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Ok(true)
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};
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let cond = self.expression(Node::Expr(cond))?;
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for alt in alternatives {
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// no matter what type of condition we have, ignore alternative if the guard evaluates false
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if !self.guard_passes(&alt.matchable.guard, &cond)? {
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continue;
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}
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match cond {
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||||
Node::PrimObject { ref tag, ref items, .. } => {
|
||||
if alt.matchable.tag.map(|t| t == *tag).unwrap_or(true) {
|
||||
let mut inner_state = self.new_frame(items, &alt.matchable.bound_vars);
|
||||
if all_subpatterns_pass(&mut inner_state, &alt.matchable.subpatterns, items)? {
|
||||
return inner_state.block(alt.item);
|
||||
} else {
|
||||
continue;
|
||||
}
|
||||
}
|
||||
},
|
||||
Node::PrimTuple { ref items } => {
|
||||
let mut inner_state = self.new_frame(items, &alt.matchable.bound_vars);
|
||||
if all_subpatterns_pass(&mut inner_state, &alt.matchable.subpatterns, items)? {
|
||||
return inner_state.block(alt.item);
|
||||
} else {
|
||||
continue;
|
||||
}
|
||||
},
|
||||
Node::Expr(ref _e) => {
|
||||
if alt.matchable.tag.is_none() {
|
||||
return self.block(alt.item)
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
Err(format!("{:?} failed pattern match", cond))
|
||||
}
|
||||
}
|
||||
|
|
@ -1,32 +0,0 @@
|
|||
#![cfg(test)]
|
||||
|
||||
use crate::symbol_table::SymbolTable;
|
||||
use crate::reduced_ast::reduce;
|
||||
use crate::eval::State;
|
||||
|
||||
fn evaluate_all_outputs(input: &str) -> Vec<Result<String, String>> {
|
||||
let ast = crate::util::quick_ast(input);
|
||||
|
||||
let mut symbol_table = SymbolTable::new();
|
||||
symbol_table.process_ast(&ast).unwrap();
|
||||
|
||||
let reduced = reduce(&ast, &symbol_table);
|
||||
|
||||
let mut state = State::new();
|
||||
|
||||
state.evaluate(reduced, true)
|
||||
}
|
||||
|
||||
macro_rules! test_in_fresh_env {
|
||||
($string:expr, $correct:expr) => {
|
||||
{
|
||||
let all_output = evaluate_all_outputs($string);
|
||||
let output = &all_output.last().unwrap();
|
||||
assert_eq!(**output, Ok($correct.to_string()));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
|
|
@ -1,514 +0,0 @@
|
|||
//! # Reduced AST
|
||||
//! The reduced AST is a minimal AST designed to be built from the full AST after all possible
|
||||
//! static checks have been done. Consequently, the AST reduction phase does very little error
|
||||
//! checking itself - any errors should ideally be caught either by an earlier phase, or are
|
||||
//! runtime errors that the evaluator should handle. That said, becuase it does do table lookups
|
||||
//! that can in principle fail [especially at the moment with most static analysis not yet complete],
|
||||
//! there is an Expr variant `ReductionError` to handle these cases.
|
||||
//!
|
||||
//! A design decision to make - should the ReducedAST types contain all information about
|
||||
//! type/layout necessary for the evaluator to work? If so, then the evaluator should not
|
||||
//! have access to the symbol table at all and ReducedAST should carry that information. If not,
|
||||
//! then ReducedAST shouldn't be duplicating information that can be queried at runtime from the
|
||||
//! symbol table. But I think the former might make sense since ultimately the bytecode will be
|
||||
//! built from the ReducedAST.
|
||||
|
||||
use std::convert::TryFrom;
|
||||
use std::rc::Rc;
|
||||
use std::str::FromStr;
|
||||
|
||||
use crate::ast::*;
|
||||
use crate::builtin::Builtin;
|
||||
use crate::symbol_table::{Symbol, SymbolSpec, SymbolTable};
|
||||
use crate::util::deref_optional_box;
|
||||
|
||||
mod types;
|
||||
pub use types::*;
|
||||
|
||||
pub fn reduce(ast: &AST, symbol_table: &SymbolTable) -> ReducedAST {
|
||||
let mut reducer = Reducer { symbol_table };
|
||||
reducer.ast(ast)
|
||||
}
|
||||
|
||||
struct Reducer<'a> {
|
||||
symbol_table: &'a SymbolTable,
|
||||
}
|
||||
|
||||
impl<'a> Reducer<'a> {
|
||||
fn ast(&mut self, ast: &AST) -> ReducedAST {
|
||||
let mut output = vec![];
|
||||
for statement in ast.statements.iter() {
|
||||
output.push(self.statement(statement));
|
||||
}
|
||||
ReducedAST(output)
|
||||
}
|
||||
|
||||
fn statement(&mut self, stmt: &Statement) -> Stmt {
|
||||
match &stmt.kind {
|
||||
StatementKind::Expression(expr) => Stmt::Expr(self.expression(expr)),
|
||||
StatementKind::Declaration(decl) => self.declaration(decl),
|
||||
StatementKind::Import(_) => Stmt::Noop,
|
||||
StatementKind::Module(modspec) => {
|
||||
for statement in modspec.contents.iter() {
|
||||
self.statement(statement);
|
||||
}
|
||||
Stmt::Noop
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[allow(clippy::ptr_arg)]
|
||||
fn block(&mut self, block: &Block) -> Vec<Stmt> {
|
||||
block.iter().map(|stmt| self.statement(stmt)).collect()
|
||||
}
|
||||
|
||||
fn invocation_argument(&mut self, invoc: &InvocationArgument) -> Expr {
|
||||
use crate::ast::InvocationArgument::*;
|
||||
match invoc {
|
||||
Positional(ex) => self.expression(ex),
|
||||
Keyword { .. } => Expr::UnimplementedSigilValue,
|
||||
Ignored => Expr::UnimplementedSigilValue,
|
||||
}
|
||||
}
|
||||
|
||||
fn expression(&mut self, expr: &Expression) -> Expr {
|
||||
use crate::ast::ExpressionKind::*;
|
||||
let input = &expr.kind;
|
||||
match input {
|
||||
NatLiteral(n) => Expr::Lit(Lit::Nat(*n)),
|
||||
FloatLiteral(f) => Expr::Lit(Lit::Float(*f)),
|
||||
StringLiteral(s) => Expr::Lit(Lit::StringLit(s.clone())),
|
||||
BoolLiteral(b) => Expr::Lit(Lit::Bool(*b)),
|
||||
BinExp(binop, lhs, rhs) => self.binop(binop, lhs, rhs),
|
||||
PrefixExp(op, arg) => self.prefix(op, arg),
|
||||
Value(qualified_name) => self.value(qualified_name),
|
||||
Call { f, arguments } => self.reduce_call_expression(f, arguments),
|
||||
TupleLiteral(exprs) => Expr::Tuple(exprs.iter().map(|e| self.expression(e)).collect()),
|
||||
IfExpression {
|
||||
discriminator,
|
||||
body,
|
||||
} => self.reduce_if_expression(deref_optional_box(discriminator), body),
|
||||
Lambda { params, body, .. } => self.reduce_lambda(params, body),
|
||||
NamedStruct { name, fields } => self.reduce_named_struct(name, fields),
|
||||
Index { .. } => Expr::UnimplementedSigilValue,
|
||||
WhileExpression { .. } => Expr::UnimplementedSigilValue,
|
||||
ForExpression { .. } => Expr::UnimplementedSigilValue,
|
||||
ListLiteral { .. } => Expr::UnimplementedSigilValue,
|
||||
}
|
||||
}
|
||||
|
||||
fn value(&mut self, qualified_name: &QualifiedName) -> Expr {
|
||||
let Symbol {
|
||||
local_name, spec, ..
|
||||
} = match self.symbol_table.lookup_symbol(&qualified_name.id) {
|
||||
Some(s) => s,
|
||||
//TODO this causes several evaluation tests to fail, figure out what's going on here
|
||||
//None => return Expr::ReductionError(format!("Symbol {:?} not found", sym_name)),
|
||||
None => {
|
||||
let name = qualified_name.components.last().unwrap().clone();
|
||||
return Expr::Sym(name);
|
||||
}
|
||||
};
|
||||
|
||||
match spec {
|
||||
SymbolSpec::RecordConstructor { .. } => Expr::ReductionError(
|
||||
"AST reducer doesn't expect a RecordConstructor here".to_string(),
|
||||
),
|
||||
SymbolSpec::DataConstructor {
|
||||
index,
|
||||
arity,
|
||||
type_name,
|
||||
} => Expr::Constructor {
|
||||
type_name: type_name.clone(),
|
||||
name: local_name.clone(),
|
||||
tag: *index,
|
||||
arity: *arity,
|
||||
},
|
||||
SymbolSpec::Func(_) => Expr::Sym(local_name.clone()),
|
||||
SymbolSpec::GlobalBinding => Expr::Sym(local_name.clone()), //TODO not sure if this is right, probably needs to eventually be fqsn
|
||||
_ => Expr::UnimplementedSigilValue,
|
||||
}
|
||||
}
|
||||
|
||||
#[allow(clippy::ptr_arg)]
|
||||
fn reduce_lambda(&mut self, params: &[FormalParam], body: &Block) -> Expr {
|
||||
Expr::Func(Func::UserDefined {
|
||||
name: None,
|
||||
params: params.iter().map(|param| param.name.clone()).collect(),
|
||||
body: self.block(body),
|
||||
})
|
||||
}
|
||||
|
||||
fn reduce_named_struct(
|
||||
&mut self,
|
||||
name: &QualifiedName,
|
||||
fields: &[(Rc<String>, Expression)],
|
||||
) -> Expr {
|
||||
let symbol = match self.symbol_table.lookup_symbol(&name.id) {
|
||||
Some(fqsn) => fqsn,
|
||||
None => return Expr::ReductionError(format!("FQSN lookup for name {:?} failed", name)),
|
||||
};
|
||||
|
||||
let (type_name, index, members_from_table) = match &symbol.spec {
|
||||
SymbolSpec::RecordConstructor {
|
||||
members,
|
||||
type_name,
|
||||
index,
|
||||
} => (type_name.clone(), index, members),
|
||||
_ => return Expr::ReductionError("Not a record constructor".to_string()),
|
||||
};
|
||||
|
||||
let arity = members_from_table.len();
|
||||
|
||||
let mut args: Vec<(Rc<String>, Expr)> = fields
|
||||
.iter()
|
||||
.map(|(name, expr)| (name.clone(), self.expression(expr)))
|
||||
.collect();
|
||||
|
||||
args.as_mut_slice()
|
||||
.sort_unstable_by(|(name1, _), (name2, _)| name1.cmp(name2)); //arbitrary - sorting by alphabetical order
|
||||
|
||||
let args = args.into_iter().map(|(_, expr)| expr).collect();
|
||||
|
||||
//TODO make sure this sorting actually works
|
||||
let f = box Expr::Constructor {
|
||||
type_name,
|
||||
name: symbol.local_name.clone(),
|
||||
tag: *index,
|
||||
arity,
|
||||
};
|
||||
Expr::Call { f, args }
|
||||
}
|
||||
|
||||
fn reduce_call_expression(
|
||||
&mut self,
|
||||
func: &Expression,
|
||||
arguments: &[InvocationArgument],
|
||||
) -> Expr {
|
||||
Expr::Call {
|
||||
f: Box::new(self.expression(func)),
|
||||
args: arguments
|
||||
.iter()
|
||||
.map(|arg| self.invocation_argument(arg))
|
||||
.collect(),
|
||||
}
|
||||
}
|
||||
|
||||
fn reduce_if_expression(
|
||||
&mut self,
|
||||
discriminator: Option<&Expression>,
|
||||
body: &IfExpressionBody,
|
||||
) -> Expr {
|
||||
let cond = Box::new(match discriminator {
|
||||
Some(expr) => self.expression(expr),
|
||||
None => return Expr::ReductionError("blank cond if-expr not supported".to_string()),
|
||||
});
|
||||
|
||||
match body {
|
||||
IfExpressionBody::SimpleConditional {
|
||||
then_case,
|
||||
else_case,
|
||||
} => {
|
||||
let then_clause = self.block(then_case);
|
||||
let else_clause = match else_case.as_ref() {
|
||||
None => vec![],
|
||||
Some(stmts) => self.block(stmts),
|
||||
};
|
||||
Expr::Conditional {
|
||||
cond,
|
||||
then_clause,
|
||||
else_clause,
|
||||
}
|
||||
}
|
||||
IfExpressionBody::SimplePatternMatch {
|
||||
pattern,
|
||||
then_case,
|
||||
else_case,
|
||||
} => {
|
||||
let then_clause = self.block(then_case);
|
||||
let else_clause = match else_case.as_ref() {
|
||||
None => vec![],
|
||||
Some(stmts) => self.block(stmts),
|
||||
};
|
||||
|
||||
let alternatives = vec![
|
||||
pattern.to_alternative(then_clause, self.symbol_table),
|
||||
Alternative {
|
||||
matchable: Subpattern {
|
||||
tag: None,
|
||||
subpatterns: vec![],
|
||||
bound_vars: vec![],
|
||||
guard: None,
|
||||
},
|
||||
item: else_clause,
|
||||
},
|
||||
];
|
||||
Expression::CaseMatch { cond, alternatives }
|
||||
},
|
||||
IfExpressionBody::CondList(ref condition_arms) => {
|
||||
let mut alternatives = vec![];
|
||||
for arm in condition_arms {
|
||||
match arm.condition {
|
||||
Condition::Expression(ref _expr) => return Expr::UnimplementedSigilValue,
|
||||
Condition::Pattern(ref p) => {
|
||||
let item = self.block(&arm.body);
|
||||
let alt = p.to_alternative(item, self.symbol_table);
|
||||
alternatives.push(alt);
|
||||
}
|
||||
Condition::TruncatedOp(_, _) => return Expr::UnimplementedSigilValue,
|
||||
Condition::Else => return Expr::UnimplementedSigilValue,
|
||||
}
|
||||
}
|
||||
Expr::CaseMatch { cond, alternatives }
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn binop(&mut self, binop: &BinOp, lhs: &Expression, rhs: &Expression) -> Expr {
|
||||
let operation = Builtin::from_str(binop.sigil()).ok();
|
||||
match operation {
|
||||
Some(Builtin::Assignment) => Expr::Assign {
|
||||
val: Box::new(self.expression(&*lhs)),
|
||||
expr: Box::new(self.expression(&*rhs)),
|
||||
},
|
||||
Some(op) => {
|
||||
let f = Box::new(Expr::Func(Func::BuiltIn(op)));
|
||||
Expr::Call {
|
||||
f,
|
||||
args: vec![self.expression(&*lhs), self.expression(&*rhs)],
|
||||
}
|
||||
}
|
||||
None => {
|
||||
//TODO handle a user-defined operation
|
||||
Expr::UnimplementedSigilValue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn prefix(&mut self, prefix: &PrefixOp, arg: &Expression) -> Expr {
|
||||
let builtin: Option<Builtin> = TryFrom::try_from(prefix).ok();
|
||||
match builtin {
|
||||
Some(op) => {
|
||||
let f = Box::new(Expr::Func(Func::BuiltIn(op)));
|
||||
Expr::Call {
|
||||
f,
|
||||
args: vec![self.expression(arg)],
|
||||
}
|
||||
}
|
||||
None => {
|
||||
//TODO need this for custom prefix ops
|
||||
Expr::UnimplementedSigilValue
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn declaration(&mut self, declaration: &Declaration) -> Stmt {
|
||||
use self::Declaration::*;
|
||||
match declaration {
|
||||
Binding {
|
||||
name,
|
||||
constant,
|
||||
expr,
|
||||
..
|
||||
} => Stmt::Binding {
|
||||
name: name.clone(),
|
||||
constant: *constant,
|
||||
expr: self.expression(expr),
|
||||
},
|
||||
FuncDecl(Signature { name, params, .. }, statements) => Stmt::PreBinding {
|
||||
name: name.clone(),
|
||||
func: Func::UserDefined {
|
||||
name: Some(name.clone()),
|
||||
params: params.iter().map(|param| param.name.clone()).collect(),
|
||||
body: self.block(statements),
|
||||
},
|
||||
},
|
||||
TypeDecl { .. } => Stmt::Noop,
|
||||
TypeAlias { .. } => Stmt::Noop,
|
||||
Interface { .. } => Stmt::Noop,
|
||||
Impl { .. } => Stmt::Expr(Expr::UnimplementedSigilValue),
|
||||
Annotation { .. } => Stmt::Noop,
|
||||
_ => Stmt::Expr(Expr::UnimplementedSigilValue),
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn handle_symbol(
|
||||
symbol: Option<&Symbol>,
|
||||
inner_patterns: &[Pattern],
|
||||
symbol_table: &SymbolTable,
|
||||
) -> Subpattern {
|
||||
use self::Pattern::*;
|
||||
let tag = symbol.map(|symbol| match symbol.spec {
|
||||
SymbolSpec::DataConstructor { index, .. } => index,
|
||||
_ => {
|
||||
panic!("Symbol is not a data constructor - this should've been caught in type-checking")
|
||||
}
|
||||
});
|
||||
let bound_vars = inner_patterns
|
||||
.iter()
|
||||
.map(|p| match p {
|
||||
VarOrName(qualified_name) => {
|
||||
let symbol_exists = symbol_table.lookup_symbol(&qualified_name.id).is_some();
|
||||
if symbol_exists {
|
||||
None
|
||||
} else {
|
||||
let QualifiedName { components, .. } = qualified_name;
|
||||
if components.len() == 1 {
|
||||
Some(components[0].clone())
|
||||
} else {
|
||||
panic!("Bad variable name in pattern");
|
||||
}
|
||||
}
|
||||
}
|
||||
_ => None,
|
||||
})
|
||||
.collect();
|
||||
|
||||
let subpatterns = inner_patterns
|
||||
.iter()
|
||||
.map(|p| match p {
|
||||
Ignored => None,
|
||||
VarOrName(_) => None,
|
||||
Literal(other) => Some(other.to_subpattern(symbol_table)),
|
||||
tp @ TuplePattern(_) => Some(tp.to_subpattern(symbol_table)),
|
||||
ts @ TupleStruct(_, _) => Some(ts.to_subpattern(symbol_table)),
|
||||
Record(..) => unimplemented!(),
|
||||
})
|
||||
.collect();
|
||||
|
||||
let guard = None;
|
||||
/*
|
||||
let guard_equality_exprs: Vec<Expr> = subpatterns.iter().map(|p| match p {
|
||||
Literal(lit) => match lit {
|
||||
_ => unimplemented!()
|
||||
},
|
||||
_ => unimplemented!()
|
||||
}).collect();
|
||||
*/
|
||||
|
||||
Subpattern {
|
||||
tag,
|
||||
subpatterns,
|
||||
guard,
|
||||
bound_vars,
|
||||
}
|
||||
}
|
||||
|
||||
impl Pattern {
|
||||
fn to_alternative(&self, item: Vec<Stmt>, symbol_table: &SymbolTable) -> Alternative {
|
||||
let s = self.to_subpattern(symbol_table);
|
||||
Alternative {
|
||||
matchable: Subpattern {
|
||||
tag: s.tag,
|
||||
subpatterns: s.subpatterns,
|
||||
bound_vars: s.bound_vars,
|
||||
guard: s.guard,
|
||||
},
|
||||
item,
|
||||
}
|
||||
}
|
||||
|
||||
fn to_subpattern(&self, symbol_table: &SymbolTable) -> Subpattern {
|
||||
use self::Pattern::*;
|
||||
match self {
|
||||
TupleStruct(QualifiedName { components, id }, inner_patterns) => {
|
||||
match symbol_table.lookup_symbol(id) {
|
||||
Some(symbol) => handle_symbol(Some(symbol), inner_patterns, symbol_table),
|
||||
None => panic!("Symbol {:?} not found", components),
|
||||
}
|
||||
}
|
||||
TuplePattern(inner_patterns) => handle_symbol(None, inner_patterns, symbol_table),
|
||||
Record(_name, _pairs) => {
|
||||
unimplemented!()
|
||||
}
|
||||
Ignored => Subpattern {
|
||||
tag: None,
|
||||
subpatterns: vec![],
|
||||
guard: None,
|
||||
bound_vars: vec![],
|
||||
},
|
||||
Literal(lit) => lit.to_subpattern(symbol_table),
|
||||
VarOrName(QualifiedName { components, id }) => {
|
||||
// if symbol is Some, treat this as a symbol pattern. If it's None, treat it
|
||||
// as a variable.
|
||||
match symbol_table.lookup_symbol(id) {
|
||||
Some(symbol) => handle_symbol(Some(symbol), &[], symbol_table),
|
||||
None => {
|
||||
println!("Components: {:?}", components);
|
||||
let name = if components.len() == 1 {
|
||||
components[0].clone()
|
||||
} else {
|
||||
panic!("check this line of code yo");
|
||||
};
|
||||
Subpattern {
|
||||
tag: None,
|
||||
subpatterns: vec![],
|
||||
guard: None,
|
||||
bound_vars: vec![Some(name)],
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl PatternLiteral {
|
||||
fn to_subpattern(&self, _symbol_table: &SymbolTable) -> Subpattern {
|
||||
use self::PatternLiteral::*;
|
||||
match self {
|
||||
NumPattern { neg, num } => {
|
||||
let comparison = Expr::Lit(match (neg, num) {
|
||||
(false, ExpressionKind::NatLiteral(n)) => Lit::Nat(*n),
|
||||
(false, ExpressionKind::FloatLiteral(f)) => Lit::Float(*f),
|
||||
(true, ExpressionKind::NatLiteral(n)) => Lit::Int(-(*n as i64)),
|
||||
(true, ExpressionKind::FloatLiteral(f)) => Lit::Float(-f),
|
||||
_ => panic!("This should never happen"),
|
||||
});
|
||||
let guard = Some(Expr::Call {
|
||||
f: Box::new(Expr::Func(Func::BuiltIn(Builtin::Equality))),
|
||||
args: vec![comparison, Expr::ConditionalTargetSigilValue],
|
||||
});
|
||||
Subpattern {
|
||||
tag: None,
|
||||
subpatterns: vec![],
|
||||
guard,
|
||||
bound_vars: vec![],
|
||||
}
|
||||
}
|
||||
StringPattern(s) => {
|
||||
let guard = Some(Expr::Call {
|
||||
f: Box::new(Expr::Func(Func::BuiltIn(Builtin::Equality))),
|
||||
args: vec![
|
||||
Expr::Lit(Lit::StringLit(s.clone())),
|
||||
Expr::ConditionalTargetSigilValue,
|
||||
],
|
||||
});
|
||||
|
||||
Subpattern {
|
||||
tag: None,
|
||||
subpatterns: vec![],
|
||||
guard,
|
||||
bound_vars: vec![],
|
||||
}
|
||||
}
|
||||
BoolPattern(b) => {
|
||||
let guard = Some(if *b {
|
||||
Expr::ConditionalTargetSigilValue
|
||||
} else {
|
||||
Expr::Call {
|
||||
f: Box::new(Expr::Func(Func::BuiltIn(Builtin::BooleanNot))),
|
||||
args: vec![Expr::ConditionalTargetSigilValue],
|
||||
}
|
||||
});
|
||||
Subpattern {
|
||||
tag: None,
|
||||
subpatterns: vec![],
|
||||
guard,
|
||||
bound_vars: vec![],
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -1,98 +0,0 @@
|
|||
#![allow(clippy::enum_variant_names)]
|
||||
|
||||
use crate::builtin::Builtin;
|
||||
use std::rc::Rc;
|
||||
|
||||
#[derive(Debug)]
|
||||
pub struct ReducedAST(pub Vec<Stmt>);
|
||||
|
||||
#[derive(Debug, Clone)]
|
||||
pub enum Stmt {
|
||||
PreBinding {
|
||||
name: Rc<String>,
|
||||
func: Func,
|
||||
},
|
||||
Binding {
|
||||
name: Rc<String>,
|
||||
constant: bool,
|
||||
expr: Expr,
|
||||
},
|
||||
Expr(Expr),
|
||||
Noop,
|
||||
}
|
||||
|
||||
#[derive(Debug, Clone)]
|
||||
pub enum Expr {
|
||||
Lit(Lit),
|
||||
Sym(Rc<String>), //a Sym is anything that can be looked up by name at runtime - i.e. a function or variable address
|
||||
Tuple(Vec<Expr>),
|
||||
Func(Func),
|
||||
Constructor {
|
||||
type_name: Rc<String>,
|
||||
name: Rc<String>,
|
||||
tag: usize,
|
||||
arity: usize, // n.b. arity here is always the value from the symbol table - if it doesn't match what it's being called with, that's an eval error, eval will handle it
|
||||
},
|
||||
Call {
|
||||
f: Box<Expr>,
|
||||
args: Vec<Expr>,
|
||||
},
|
||||
Assign {
|
||||
val: Box<Expr>, //TODO this probably can't be a val
|
||||
expr: Box<Expr>,
|
||||
},
|
||||
Conditional {
|
||||
cond: Box<Expr>,
|
||||
then_clause: Vec<Stmt>,
|
||||
else_clause: Vec<Stmt>,
|
||||
},
|
||||
ConditionalTargetSigilValue,
|
||||
CaseMatch {
|
||||
cond: Box<Expr>,
|
||||
alternatives: Vec<Alternative>,
|
||||
},
|
||||
UnimplementedSigilValue,
|
||||
ReductionError(String),
|
||||
}
|
||||
|
||||
impl Expr {
|
||||
// The unit value is an empty tuple
|
||||
pub fn unit() -> Expr {
|
||||
Expr::Tuple(vec![])
|
||||
}
|
||||
}
|
||||
|
||||
pub type BoundVars = Vec<Option<Rc<String>>>; //remember that order matters here
|
||||
|
||||
#[derive(Debug, Clone)]
|
||||
pub struct Alternative {
|
||||
pub matchable: Subpattern,
|
||||
pub item: Vec<Stmt>,
|
||||
}
|
||||
|
||||
#[derive(Debug, Clone)]
|
||||
pub struct Subpattern {
|
||||
pub tag: Option<usize>,
|
||||
pub subpatterns: Vec<Option<Subpattern>>,
|
||||
pub bound_vars: BoundVars,
|
||||
pub guard: Option<Expr>,
|
||||
}
|
||||
|
||||
#[derive(Debug, Clone)]
|
||||
pub enum Lit {
|
||||
Nat(u64),
|
||||
Int(i64),
|
||||
Float(f64),
|
||||
Bool(bool),
|
||||
StringLit(Rc<String>),
|
||||
}
|
||||
|
||||
#[derive(Debug, Clone)]
|
||||
pub enum Func {
|
||||
BuiltIn(Builtin),
|
||||
UserDefined {
|
||||
name: Option<Rc<String>>,
|
||||
params: Vec<Rc<String>>,
|
||||
body: Vec<Stmt>,
|
||||
},
|
||||
}
|
||||
Loading…
Reference in New Issue