Resolver - Errors on duplicate declarations

This commit is contained in:
Emmanuel BENOîT 2023-01-05 06:58:29 +01:00
parent c1a61b992d
commit 79a0667f34

View file

@ -30,12 +30,21 @@ impl ResolverState {
self.scopes.pop();
}
fn declare(&mut self, name: &Token) {
fn declare(&mut self, name: &Token) -> ResolverResult {
if !self.scopes.is_empty() {
let idx = self.scopes.len() - 1;
let top = &mut self.scopes[idx];
top.insert(name.lexeme.clone(), false);
let scope = &mut self.scopes[idx];
if scope.contains_key(&name.lexeme as &str) {
return Err(SloxError::with_token(
ErrorKind::Parse,
name,
"already a variable with this name in this scope".to_owned(),
));
} else {
scope.insert(name.lexeme.clone(), false);
}
}
return Ok(());
}
fn define(&mut self, name: &Token) {
@ -70,7 +79,7 @@ impl ResolverState {
fn resolve_function(&mut self, params: &[Token], body: &Vec<ast::StmtNode>) -> ResolverResult {
self.begin_scope();
for param in params {
self.declare(param);
self.declare(param)?;
self.define(param);
}
// Unlike the original Lox, function arguments and function bodies do
@ -93,7 +102,10 @@ trait VarResolver {
impl VarResolver for ast::ProgramNode {
fn resolve(&self, rs: &mut ResolverState) -> ResolverResult {
self.0.resolve(rs)
rs.begin_scope();
let result = self.0.resolve(rs);
rs.end_scope();
result
}
}
@ -117,19 +129,19 @@ impl VarResolver for ast::StmtNode {
}
ast::StmtNode::VarDecl(name, None) => {
rs.declare(name);
rs.declare(name)?;
rs.define(name);
Ok(())
}
ast::StmtNode::VarDecl(name, Some(init)) => {
rs.declare(name);
rs.declare(name)?;
init.resolve(rs)?;
rs.define(name);
Ok(())
}
ast::StmtNode::FunDecl { name, params, body } => {
rs.declare(name);
rs.declare(name)?;
rs.define(name);
rs.resolve_function(params, body)
}