From 47ffa8071152bcafb4b6ff87a3142bf12dbce12b Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sun, 28 Feb 2021 15:15:46 +0200 Subject: feat(tazjin/rlox): Support trivial literals in bytecode compiler Adds support for true, false & nil. These each come with a new separate opcode and are pushed directly on the stack. Change-Id: I405b5b09496dcf99d514d3411c083e0834377167 Reviewed-on: https://cl.tvl.fyi/c/depot/+/2571 Reviewed-by: tazjin Tested-by: BuildkiteCI --- users/tazjin/rlox/src/bytecode/compiler.rs | 30 ++++++++++++++++++++++++++++-- users/tazjin/rlox/src/bytecode/mod.rs | 1 - users/tazjin/rlox/src/bytecode/opcode.rs | 7 ++++++- users/tazjin/rlox/src/bytecode/tests.rs | 16 ++++++++++++++-- users/tazjin/rlox/src/bytecode/vm.rs | 4 ++++ 5 files changed, 52 insertions(+), 6 deletions(-) (limited to 'users/tazjin/rlox') diff --git a/users/tazjin/rlox/src/bytecode/compiler.rs b/users/tazjin/rlox/src/bytecode/compiler.rs index 63f34fad3ea7..95b111dba824 100644 --- a/users/tazjin/rlox/src/bytecode/compiler.rs +++ b/users/tazjin/rlox/src/bytecode/compiler.rs @@ -1,9 +1,12 @@ -use super::chunk::{self, Chunk}; +use super::chunk::Chunk; use super::errors::{Error, ErrorKind, LoxResult}; use super::opcode::OpCode; use super::value::Value; use crate::scanner::{self, Token, TokenKind}; +#[cfg(feature = "disassemble")] +use super::chunk; + struct Compiler> { tokens: T, chunk: Chunk, @@ -101,6 +104,18 @@ fn rule_for>(token: &TokenKind) -> ParseRule { ParseRule::new(Some(Compiler::number), None, Precedence::None) } + TokenKind::True => { + ParseRule::new(Some(Compiler::literal), None, Precedence::None) + } + + TokenKind::False => { + ParseRule::new(Some(Compiler::literal), None, Precedence::None) + } + + TokenKind::Nil => { + ParseRule::new(Some(Compiler::literal), None, Precedence::None) + } + _ => ParseRule::new(None, None, Precedence::None), } } @@ -180,6 +195,17 @@ impl> Compiler { Ok(()) } + fn literal(&mut self) -> LoxResult<()> { + match self.previous().kind { + TokenKind::Nil => self.emit_op(OpCode::OpNil), + TokenKind::True => self.emit_op(OpCode::OpTrue), + TokenKind::False => self.emit_op(OpCode::OpFalse), + _ => unreachable!("only called for literal value tokens"), + } + + Ok(()) + } + fn parse_precedence(&mut self, precedence: Precedence) -> LoxResult<()> { self.advance(); let rule: ParseRule = rule_for(&self.previous().kind); @@ -206,7 +232,7 @@ impl> Compiler { } fn consume(&mut self, expected: &TokenKind, err: ErrorKind) { - if (self.current().kind == *expected) { + if self.current().kind == *expected { self.advance(); return; } diff --git a/users/tazjin/rlox/src/bytecode/mod.rs b/users/tazjin/rlox/src/bytecode/mod.rs index 3c7dad97be3e..27fa7c0f677e 100644 --- a/users/tazjin/rlox/src/bytecode/mod.rs +++ b/users/tazjin/rlox/src/bytecode/mod.rs @@ -12,7 +12,6 @@ mod vm; #[cfg(test)] mod tests; -use chunk::Chunk; pub struct Interpreter {} impl crate::Lox for Interpreter { diff --git a/users/tazjin/rlox/src/bytecode/opcode.rs b/users/tazjin/rlox/src/bytecode/opcode.rs index 0f070ce9fffc..057fa7697719 100644 --- a/users/tazjin/rlox/src/bytecode/opcode.rs +++ b/users/tazjin/rlox/src/bytecode/opcode.rs @@ -1,8 +1,13 @@ #[derive(Debug)] pub enum OpCode { - /// Access a constant for use. + /// Push a constant onto the stack. OpConstant(usize), + // Literal pushes + OpNil, + OpTrue, + OpFalse, + /// Return from the current function. OpReturn, diff --git a/users/tazjin/rlox/src/bytecode/tests.rs b/users/tazjin/rlox/src/bytecode/tests.rs index 5a0901be6d79..d9a752b38788 100644 --- a/users/tazjin/rlox/src/bytecode/tests.rs +++ b/users/tazjin/rlox/src/bytecode/tests.rs @@ -1,12 +1,17 @@ +use super::value::Value; use super::*; use crate::Lox; -fn expect_num(code: &str, value: f64) { +fn expect(code: &str, value: Value) { let result = Interpreter::create() .interpret(code.into()) .expect("evaluation failed"); - assert_eq!(result, value::Value::Number(value)); + assert_eq!(result, value); +} + +fn expect_num(code: &str, value: f64) { + expect(code, Value::Number(value)) } #[test] @@ -46,3 +51,10 @@ fn arithmetic() { expect_num("-4 * -4 + (14 - 5)", 25.0); expect_num("(702 + 408) - ((239 - 734) / -5) + -4", 1007.0); } + +#[test] +fn trivial_literals() { + expect("true", Value::Bool(true)); + expect("false", Value::Bool(false)); + expect("nil", Value::Nil); +} diff --git a/users/tazjin/rlox/src/bytecode/vm.rs b/users/tazjin/rlox/src/bytecode/vm.rs index ee3abbd6cc18..74c3e338fce4 100644 --- a/users/tazjin/rlox/src/bytecode/vm.rs +++ b/users/tazjin/rlox/src/bytecode/vm.rs @@ -72,6 +72,10 @@ impl VM { self.push(c); } + OpCode::OpNil => self.push(Value::Nil), + OpCode::OpTrue => self.push(Value::Bool(true)), + OpCode::OpFalse => self.push(Value::Bool(false)), + OpCode::OpNegate => { let v = self.pop(); with_type!( -- cgit 1.4.1