Give State a pointer to its parent

For function call lookups
This commit is contained in:
greg 2018-02-24 13:56:04 -08:00
parent d229a57837
commit 5da7c809b2
2 changed files with 35 additions and 30 deletions

View File

@ -3,7 +3,8 @@ use schala_lang::builtin::{BinOp, PrefixOp};
use std::collections::HashMap;
use std::rc::Rc;
pub struct State {
pub struct State<'a> {
parent_frame: Option<&'a State<'a>>,
values: HashMap<Rc<String>, ValueEntry>,
}
@ -32,9 +33,29 @@ enum FullyEvaluatedExpr {
Tuple(Vec<FullyEvaluatedExpr>),
}
impl State {
pub fn new() -> State {
State { values: HashMap::new() }
impl FullyEvaluatedExpr {
fn to_string(&self) -> String {
use self::FullyEvaluatedExpr::*;
match self {
&UnsignedInt(ref n) => format!("{}", n),
&SignedInt(ref n) => format!("{}", n),
&Float(ref f) => format!("{}", f),
&Str(ref s) => format!("\"{}\"", s),
&Bool(ref b) => format!("{}", b),
&Custom { ref string_rep } => format!("{}", string_rep),
&Tuple(ref _items) => format!("(tuple to be defined later)"),
&FuncLit(ref name) => format!("<function {}>", name),
}
}
}
impl<'a> State<'a> {
pub fn new() -> State<'a> {
State { parent_frame: None, values: HashMap::new() }
}
pub fn new_with_parent(parent: &'a State<'a>) -> State<'a> {
State { parent_frame: Some(parent), values: HashMap::new() }
}
pub fn evaluate(&mut self, ast: AST) -> Vec<String> {
@ -42,8 +63,8 @@ impl State {
for statement in ast.0 {
match self.eval_statement(statement) {
Ok(output) => {
if let Some(s) = output {
acc.push(s);
if let Some(fully_evaluated) = output {
acc.push(fully_evaluated.to_string());
}
},
Err(error) => {
@ -56,28 +77,12 @@ impl State {
}
}
impl State {
fn eval_statement(&mut self, statement: Statement) -> EvalResult<Option<String>> {
use self::FullyEvaluatedExpr::*;
match statement {
Statement::ExpressionStatement(expr) => {
self.eval_expr(expr).map( |eval| {
match eval {
UnsignedInt(n) => Some(format!("{}", n)),
SignedInt(n) => Some(format!("{}", n)),
Float(f) => Some(format!("{}", f)),
Str(s) => Some(format!("\"{}\"", s)),
Bool(b) => Some(format!("{}", b)),
Custom { string_rep } => Some(format!("{}", string_rep)),
Tuple(_items) => Some(format!("(tuple to be defined later)")),
FuncLit(name) => Some(format!("<function {}>", name)),
}
})
},
Statement::Declaration(decl) => {
self.eval_decl(decl).map(|_| None)
}
}
impl<'a> State<'a> {
fn eval_statement(&mut self, statement: Statement) -> EvalResult<Option<FullyEvaluatedExpr>> {
Ok(match statement {
Statement::ExpressionStatement(expr) => Some(self.eval_expr(expr)?),
Statement::Declaration(decl) => { self.eval_decl(decl)?; None }
})
}
fn eval_decl(&mut self, decl: Declaration) -> EvalResult<()> {
@ -138,7 +143,7 @@ impl State {
Expression(Value(identifier, _), _) => {
match self.values.get(&identifier) {
Some(&ValueEntry::Function { ref body }) => {
let new_state = State::new();
let new_state = State::new_with_parent(self);
let sub_ast = AST(body.clone());
println!("LOL ALL FUNCTIONS EVALUATE TO 2!");
Ok(FullyEvaluatedExpr::UnsignedInt(2))

View File

@ -16,7 +16,7 @@ mod eval;
use self::typechecking::{TypeContext};
pub struct Schala {
state: eval::State,
state: eval::State<'static>,
type_context: TypeContext
}