Wire up resolver to interpreter

This commit is contained in:
Brandon Dyck 2023-10-04 17:13:48 -06:00
parent 5168890ea0
commit 6e88a41b72
4 changed files with 283 additions and 241 deletions

View File

@ -64,6 +64,20 @@ public class Env
}
}
}
public Env Ancestor(int distance)
{
Env? curr = this;
for (int i = 0; i < distance; i++)
{
curr = curr.enclosing;
if (curr is null)
{
throw new IndexOutOfRangeException();
}
}
return curr;
}
}
public interface Callable
@ -302,14 +316,16 @@ public class Interpreter : AST.IExprVisitor<Env, object>
binding.Params[i].accept((arguments[i], env), new PatternBinder());
}
return interpreter.evaluate(env, binding.Value);
// throw new NotImplementedException();
}
}
protected internal readonly Env Globals = new Env();
private readonly Resolver Resolver;
public Interpreter()
public Interpreter(Resolver resolver)
{
Resolver = resolver;
Globals["clock"] = new NativeFunction((args) =>
{
return (double)DateTimeOffset.Now.ToUnixTimeSeconds();
@ -413,14 +429,14 @@ public class Interpreter : AST.IExprVisitor<Env, object>
case TokenType.BangEqual:
return Variant.FromBool((left, right) switch
{
(String l, String r) => l != r,
(string l, string r) => l != r,
(double l, double r) => l != r,
_ => throw new ArgumentException(),
});
case TokenType.DoubleEqual:
return Variant.FromBool((left, right) switch
{
(String l, String r) => l == r,
(string l, string r) => l == r,
(double l, double r) => l == r,
_ => throw new ArgumentException(),
});
@ -453,7 +469,15 @@ public class Interpreter : AST.IExprVisitor<Env, object>
public object visitVariableExpr(Env env, AST.Variable expr)
{
return env[expr.Value];
var name = (string)expr.Value.Literal!;
if (Resolver.TryResolve(expr, out var distance))
{
return env.Ancestor(distance)[expr.Value];
}
else
{
return Globals[expr.Value];
}
}
public object visitIfExpr(Env env, AST.If expr)
@ -499,9 +523,11 @@ public class Interpreter : AST.IExprVisitor<Env, object>
}
catch (Exception e)
{
var start = e is PatternMismatchException ?
((PatternMismatchException)e).Start :
binding.Start;
var start = e switch
{
PatternMismatchException pme => pme.Start,
_ => binding.Start,
};
throw new RuntimeError(start, e.Message);
}
break;

View File

@ -7,7 +7,8 @@ namespace Finn;
class Program
{
private static readonly Interpreter interpreter = new Interpreter();
private static readonly Resolver resolver = new Resolver();
private static readonly Interpreter interpreter = new Interpreter(resolver);
static bool hadError = false;
static bool hadRuntimeError = true;
@ -41,16 +42,8 @@ class Program
{
var scanner = new Scanner(src);
List<Token> tokens = scanner.scanTokens();
// Console.WriteLine("TOKENS\n=======");
// foreach (var token in tokens)
// {
// Console.WriteLine(token);
// }
Parser parser = new Parser(tokens);
Expr? expression = parser.parse();
// Console.WriteLine("\nAST\n=======");
// Console.WriteLine(expression);
// Console.WriteLine();
if (hadError)
{
@ -58,6 +51,13 @@ class Program
return;
}
resolver.Add(expression!);
if (hadError)
{
hadError = false;
return;
}
interpreter.Interpret(expression!);
}

View File

@ -8,8 +8,24 @@ using ScopeStack = System.Collections.Immutable.ImmutableStack<System.Collection
using Resolutions = System.Collections.Immutable.ImmutableDictionary<Finn.AST.Expr, int>;
using System.Collections.Generic;
class Resolver : IExprVisitor<ScopeStack, Resolutions>
public class Resolver
{
private static readonly Resolutions EmptyResolutions = Resolutions.Empty.WithComparers(ReferenceEqualityComparer.Instance);
private Resolutions Resolutions = EmptyResolutions;
public bool TryResolve(Expr expr, out int distance)
{
return Resolutions.TryGetValue(expr, out distance);
}
public void Add(Expr expr)
{
var newResolutions = ResolverBuilder.Instance.Resolve(ScopeStack.Empty, expr);
Resolutions = Resolutions.AddRange(newResolutions);
}
private class ResolverBuilder : IExprVisitor<ScopeStack, Resolutions>
{
private class NameCollection
{
public ImmutableHashSet<string> Names { get; private set; } = ImmutableHashSet<string>.Empty;
@ -74,14 +90,13 @@ class Resolver : IExprVisitor<ScopeStack, Resolutions>
}
}
private static readonly Resolutions EmptyResolutions = Resolutions.Empty.WithComparers(ReferenceEqualityComparer.Instance);
public static readonly Resolver Instance = new Resolver();
public static readonly ResolverBuilder Instance = new ResolverBuilder();
private Resolver() { }
private ResolverBuilder() { }
private static Resolutions AddRange(Resolutions r1, Resolutions r2) => r1.AddRange(r2);
private Resolutions Resolve(ScopeStack scopes, Expr expr)
public Resolutions Resolve(ScopeStack scopes, Expr expr)
{
return expr.accept(scopes, this);
}
@ -254,4 +269,6 @@ class Resolver : IExprVisitor<ScopeStack, Resolutions>
return Resolve(scopes, names.Names, _case.Value);
}
}
}
}

View File

@ -1,4 +1,3 @@
Wire up resolver to interpreter
Move let-expr resolvability check to Resolver
Remove dynamic type checks (checkXXX methods) from interpreter
Use numerical indices in resolutions