diff options
Diffstat (limited to 'src/com/craftinginterpreters/lox/Interpreter.java')
-rw-r--r-- | src/com/craftinginterpreters/lox/Interpreter.java | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/src/com/craftinginterpreters/lox/Interpreter.java b/src/com/craftinginterpreters/lox/Interpreter.java index f752e77..407c537 100644 --- a/src/com/craftinginterpreters/lox/Interpreter.java +++ b/src/com/craftinginterpreters/lox/Interpreter.java @@ -4,7 +4,23 @@ import java.util.ArrayList; import java.util.List; class Interpreter implements Expr.Visitor<Object>, Stmt.Visitor<Void> { - private Environment environment = new Environment(); + final Environment globals = new Environment(); + private Environment environment = globals; + + Interpreter() { + globals.define("clock", new LoxCallable() { + @Override + public int arity() { return 0; } + + @Override + public Object call(Interpreter interpreter, List<Object> arguments) { + return (double)System.currentTimeMillis() / 1000.0; + } + + @Override + public String toString() { return "<native fn>"; } + }); + } @Override public Object visitLiteralExpr(Expr.Literal expr) { @@ -105,7 +121,7 @@ class Interpreter implements Expr.Visitor<Object>, Stmt.Visitor<Void> { stmt.accept(this); } - private void executeBlock(List<Stmt> statements, Environment environment) { + public void executeBlock(List<Stmt> statements, Environment environment) { Environment previous = this.environment; try { @@ -132,6 +148,13 @@ class Interpreter implements Expr.Visitor<Object>, Stmt.Visitor<Void> { } @Override + public Void visitFunctionStmt(Stmt.Function stmt) { + LoxFunction function = new LoxFunction(stmt); + environment.define(stmt.name.lexeme, function); + return null; + } + + @Override public Void visitIfStmt(Stmt.If stmt) { if (isTruthy(evaluate(stmt.condition))) { execute(stmt.thenBranch); @@ -238,7 +261,8 @@ class Interpreter implements Expr.Visitor<Object>, Stmt.Visitor<Void> { LoxCallable function = (LoxCallable) callee; if (arguments.size() != function.arity()) { - throw new RuntimeError(expr.paren, "Expected " + function.arity() + " arguments but got " + arguments.size() + "."); + throw new RuntimeError(expr.paren, + "Expected " + function.arity() + " arguments but got " + arguments.size() + "."); } return function.call(this, arguments); |