oden/fine/src/compiler.rs

322 lines
10 KiB
Rust

use crate::{
parser::{Tree, TreeKind, TreeRef},
semantics::{Location, Semantics, Type},
tokens::TokenKind,
};
// TODO: If I were cool this would by actual bytecode.
// But I'm not cool.
pub enum Instruction {
Panic,
BoolNot,
Discard,
FloatAdd,
FloatDivide,
FloatMultiply,
FloatSubtract,
Jump(usize),
JumpFalse(usize),
JumpTrue(usize),
LoadArgument(usize),
LoadLocal(usize),
LoadModule(usize),
PushFalse,
PushFloat(f64),
PushNothing,
PushString(usize),
PushTrue,
StoreLocal(usize),
}
pub struct Function {
instructions: Vec<Instruction>,
strings: Vec<String>,
}
type CR = Option<()>;
const OK: CR = CR::Some(());
pub fn compile_expression(code: &mut Function, semantics: &Semantics, t: TreeRef) {
let tree = &semantics.tree()[t];
let cr = match tree.kind {
TreeKind::Error => None,
TreeKind::LiteralExpression => compile_literal(code, semantics, t, tree),
TreeKind::GroupingExpression => compile_grouping(code, semantics, tree),
TreeKind::UnaryExpression => compile_unary_operator(code, semantics, tree),
TreeKind::ConditionalExpression => compile_condition_expression(code, semantics, tree),
TreeKind::BinaryExpression => compile_binary_expression(code, semantics, tree),
TreeKind::Identifier => compile_identifier_expression(code, semantics, t, tree),
TreeKind::CallExpression => todo!(),
TreeKind::Block => compile_block_expression(code, semantics, tree),
_ => {
semantics.internal_compiler_error(Some(t), "tree is not an expression, cannot compile")
}
};
if matches!(cr, None) {
code.instructions.push(Instruction::Panic);
}
}
fn compile_literal(code: &mut Function, semantics: &Semantics, t: TreeRef, tr: &Tree) -> CR {
let tok = tr.nth_token(0)?;
match semantics.type_of(t) {
Type::F64 => code
.instructions
.push(Instruction::PushFloat(tok.as_str().parse().unwrap())),
Type::Bool => code.instructions.push(if tok.kind == TokenKind::True {
Instruction::PushTrue
} else {
Instruction::PushFalse
}),
Type::String => {
let index = code.strings.len();
// TODO: Interpret string here make good!
let mut result = String::new();
let mut input = tok.as_str().chars();
while let Some(ch) = input.next() {
if ch == '\\' {
if let Some(ch) = input.next() {
match ch {
'n' => result.push('\n'),
'r' => result.push('\r'),
't' => result.push('\t'),
_ => result.push(ch),
}
} else {
result.push(ch)
}
} else {
result.push(ch)
}
}
code.strings.push(result);
code.instructions.push(Instruction::PushString(index))
}
Type::Error => code.instructions.push(Instruction::Panic),
_ => panic!("unsupported literal type: {t:?}"),
};
OK
}
fn compile_grouping(code: &mut Function, semantics: &Semantics, t: &Tree) -> CR {
compile_expression(code, semantics, t.nth_tree(1)?);
OK
}
fn compile_unary_operator(code: &mut Function, semantics: &Semantics, t: &Tree) -> CR {
compile_expression(code, semantics, t.nth_tree(1)?);
let tok = t.nth_token(0)?;
match tok.kind {
TokenKind::Minus => {
code.instructions.push(Instruction::PushFloat(-1.0));
code.instructions.push(Instruction::FloatMultiply);
}
TokenKind::Bang => {
code.instructions.push(Instruction::BoolNot);
}
_ => panic!("unsupported unary operator"),
}
OK
}
fn compile_condition_expression(code: &mut Function, semantics: &Semantics, t: &Tree) -> CR {
let condition = t.nth_tree(1)?;
compile_expression(code, semantics, condition);
let jump_else_index = code.instructions.len();
code.instructions.push(Instruction::JumpFalse(0));
let then_branch = t.nth_tree(2)?;
compile_expression(code, semantics, then_branch);
if let Some(else_branch) = t.nth_tree(4) {
let jump_end_index = code.instructions.len();
code.instructions.push(Instruction::Jump(0));
let else_index = code.instructions.len();
code.instructions[jump_else_index] = Instruction::JumpFalse(else_index);
compile_expression(code, semantics, else_branch);
let end_index = code.instructions.len();
code.instructions[jump_end_index] = Instruction::Jump(end_index);
} else {
let else_index = code.instructions.len();
code.instructions[jump_else_index] = Instruction::JumpFalse(else_index);
}
OK
}
fn compile_binary_expression(code: &mut Function, semantics: &Semantics, t: &Tree) -> CR {
compile_expression(code, semantics, t.nth_tree(0)?);
match t.nth_token(1)?.kind {
TokenKind::Plus => {
compile_expression(code, semantics, t.nth_tree(2)?);
code.instructions.push(Instruction::FloatAdd);
}
TokenKind::Minus => {
compile_expression(code, semantics, t.nth_tree(2)?);
code.instructions.push(Instruction::FloatSubtract);
}
TokenKind::Star => {
compile_expression(code, semantics, t.nth_tree(2)?);
code.instructions.push(Instruction::FloatMultiply);
}
TokenKind::Slash => {
compile_expression(code, semantics, t.nth_tree(2)?);
code.instructions.push(Instruction::FloatDivide);
}
TokenKind::And => {
let jump_false_index = code.instructions.len();
code.instructions.push(Instruction::JumpFalse(0));
code.instructions.push(Instruction::PushTrue);
let jump_end_index = code.instructions.len();
code.instructions.push(Instruction::Jump(0));
let false_index = code.instructions.len();
code.instructions[jump_false_index] = Instruction::JumpFalse(false_index);
compile_expression(code, semantics, t.nth_tree(2)?);
let end_index = code.instructions.len();
code.instructions[jump_end_index] = Instruction::Jump(end_index);
}
TokenKind::Or => {
let jump_true_index = code.instructions.len();
code.instructions.push(Instruction::JumpTrue(0));
code.instructions.push(Instruction::PushTrue);
let jump_end_index = code.instructions.len();
code.instructions.push(Instruction::Jump(0));
let true_index = code.instructions.len();
code.instructions[jump_true_index] = Instruction::JumpTrue(true_index);
compile_expression(code, semantics, t.nth_tree(2)?);
let end_index = code.instructions.len();
code.instructions[jump_end_index] = Instruction::Jump(end_index);
}
_ => panic!("Unsupported binary expression"),
}
OK
}
fn compile_identifier_expression(
code: &mut Function,
semantics: &Semantics,
t: TreeRef,
tree: &Tree,
) -> Option<()> {
let ident = tree.nth_token(0)?;
let environment = semantics.environment_of(t);
let declaration = environment.bind(ident)?;
let instruction = match declaration.location {
Location::Local => Instruction::LoadLocal(declaration.index),
Location::Argument => Instruction::LoadArgument(declaration.index),
Location::Module => Instruction::LoadModule(declaration.index),
};
code.instructions.push(instruction);
OK
}
fn compile_block_expression(code: &mut Function, semantics: &Semantics, tree: &Tree) -> Option<()> {
let last_is_brace = tree.nth_token(tree.children.len() - 1).is_some();
let last_index = tree.children.len() - if last_is_brace { 2 } else { 1 };
for i in 1..last_index {
compile_statement(code, semantics, tree.nth_tree(i)?, false);
}
compile_statement(code, semantics, tree.nth_tree(last_index)?, true);
OK
}
pub fn compile_statement(code: &mut Function, semantics: &Semantics, t: TreeRef, gen_value: bool) {
let tree = &semantics.tree()[t];
let cr = match tree.kind {
TreeKind::FunctionDecl => compile_function_declaration(code, semantics, tree, gen_value),
TreeKind::LetStatement => compile_let_statement(code, semantics, t, tree, gen_value),
TreeKind::ExpressionStatement => {
compile_expression_statement(code, semantics, tree, gen_value)
}
TreeKind::IfStatement => compile_if_statement(code, semantics, tree, gen_value),
_ => panic!("unsupported tree kind {:?}", tree.kind),
};
if matches!(cr, None) {
code.instructions.push(Instruction::Panic);
}
}
fn compile_if_statement(
code: &mut Function,
semantics: &Semantics,
tree: &Tree,
gen_value: bool,
) -> CR {
compile_expression(code, semantics, tree.nth_tree(0)?);
if !gen_value {
code.instructions.push(Instruction::Discard);
}
OK
}
fn compile_expression_statement(
code: &mut Function,
semantics: &Semantics,
tree: &Tree,
gen_value: bool,
) -> CR {
compile_expression(code, semantics, tree.nth_tree(0)?);
if tree
.nth_token(1)
.is_some_and(|t| t.kind == TokenKind::Semicolon)
{
code.instructions.push(Instruction::Discard);
if gen_value {
code.instructions.push(Instruction::PushNothing);
}
} else if !gen_value {
code.instructions.push(Instruction::Discard);
}
OK
}
fn compile_let_statement(
code: &mut Function,
semantics: &Semantics,
t: TreeRef,
tree: &Tree,
gen_value: bool,
) -> CR {
compile_expression(code, semantics, tree.nth_tree(3)?);
let environment = semantics.environment_of(t);
let declaration = environment.bind(tree.nth_token(1)?)?;
// NOTE: Because this is a let statement I assume it's local!
assert!(matches!(declaration.location, Location::Local));
code.instructions
.push(Instruction::StoreLocal(declaration.index));
if gen_value {
code.instructions.push(Instruction::PushNothing);
}
OK
}
fn compile_function_declaration(
_code: &mut Function,
_semantics: &Semantics,
_tree: &Tree,
_gen_value: bool,
) -> CR {
todo!()
}