Refactoring codegen

This commit is contained in:
2026-05-04 07:12:05 +02:00
parent a4c1f787ff
commit 257877319e
+193 -160
View File
@@ -3,6 +3,26 @@ use parser::ast::{
VarDeclStmt, WhileStmt,
};
// ---------------------------------------------------------------------------
// Traits
// ---------------------------------------------------------------------------
/// Implemented by nodes that *write* into the codegen output buffer.
/// Requires `&mut RustCodegen` because it calls `add` / `addln` / indentation helpers.
pub trait ToRust {
fn to_rust(&self, cg: &mut RustCodegen);
}
/// Implemented by nodes that *produce* a `String` without mutating the codegen.
/// Only needs `&RustCodegen` (e.g. for indent level or helper access).
pub trait GetRust {
fn get_rust(&self, cg: &RustCodegen) -> String;
}
// ---------------------------------------------------------------------------
// Codegen struct
// ---------------------------------------------------------------------------
pub struct RustCodegen {
output: String,
indent: usize,
@@ -30,21 +50,136 @@ impl RustCodegen {
}
fn add_indentedln(&mut self, s: &str) {
self.add(&format!("{}{}\n", self.indent_str(), s));
let line = format!("{}{}\n", self.indent_str(), s);
self.add(&line);
}
pub fn generate(&mut self, toplevels: &[TopLevel]) -> String {
for tl in toplevels {
self.generate_toplevel(tl);
tl.to_rust(self);
}
self.output.clone()
}
}
fn generate_toplevel(&mut self, tl: &TopLevel) {
match tl {
impl Default for RustCodegen {
fn default() -> Self {
Self::new()
}
}
// ---------------------------------------------------------------------------
// GetRust — pure string production (expressions, types)
// ---------------------------------------------------------------------------
impl GetRust for TypeExpr {
fn get_rust(&self, _cg: &RustCodegen) -> String {
match self {
TypeExpr::Identifier(name) => match name.as_str() {
"int" => "i32".into(),
"float" | "float64" => "f64".into(),
"float32" => "f32".into(),
"bool" => "bool".into(),
"string" => "String".into(),
_ => name.clone(),
},
}
}
}
impl GetRust for Expression {
fn get_rust(&self, cg: &RustCodegen) -> String {
match self {
Expression::Identifier(name) => name.clone(),
Expression::IntLiteral(n) => n.to_string(),
Expression::FloatLiteral(n) => n.to_string(),
Expression::BoolLiteral(b) => b.to_string(),
Expression::StringLiteral(s) => format!("\"{}\".to_string()", s),
Expression::Postfix { initial, postfixes } => {
let base = initial.get_rust(cg);
postfixes.get_rust_with_base(cg, &base)
}
}
}
}
/// Helper — applies a slice of postfixes onto an already-rendered base string.
trait PostfixChain {
fn get_rust_with_base(&self, cg: &RustCodegen, base: &str) -> String;
}
impl PostfixChain for [Postfix] {
fn get_rust_with_base(&self, cg: &RustCodegen, base: &str) -> String {
let mut result = base.to_string();
for postfix in self {
result = match postfix {
Postfix::FieldAccess(field) => format!("{}.{}", result, field),
Postfix::Call(args) => {
let args = args
.iter()
.map(|a| a.get_rust(cg))
.collect::<Vec<_>>()
.join(", ");
format!("{}({})", result, args)
}
Postfix::StructCall(fields) => {
let fields = fields
.iter()
.map(|(k, v)| format!("{}: {}", k, v.get_rust(cg)))
.collect::<Vec<_>>()
.join(", ");
format!("{} {{ {} }}", result, fields)
}
Postfix::Index(idx) => {
format!("{}[{}]", result, idx.get_rust(cg))
}
Postfix::Binary(op, rhs) => {
let op_str = match op {
BinaryOp::Plus => "+",
BinaryOp::Minus => "-",
BinaryOp::Multiply => "*",
BinaryOp::Divide => "/",
BinaryOp::Modulo => "%",
BinaryOp::Equal => "==",
BinaryOp::NotEqual => "!=",
BinaryOp::LessThan => "<",
BinaryOp::GreaterThan => ">",
BinaryOp::LessThanOrEqual => "<=",
BinaryOp::GreaterThanOrEqual => ">=",
};
format!("{} {} {}", result, op_str, rhs.get_rust(cg))
}
};
}
result
}
}
// ---------------------------------------------------------------------------
// ToRust — output-writing (top-level, statements, blocks)
// ---------------------------------------------------------------------------
impl ToRust for Block {
fn to_rust(&self, cg: &mut RustCodegen) {
for stmt in &self.0 {
stmt.to_rust(cg);
}
}
}
impl ToRust for TopLevel {
fn to_rust(&self, cg: &mut RustCodegen) {
match self {
TopLevel::Import(path) => {
let path = path.replace("\"", "");
self.addln(&format!("use {};", path));
let path = path.replace('"', "");
cg.addln(&format!("use {};", path));
}
TopLevel::StructDecl {
@@ -53,17 +188,16 @@ impl RustCodegen {
fields,
} => {
let vis = if *export { "pub " } else { "" };
self.addln(&format!("{}struct {} {{", vis, name));
self.indent += 1;
cg.addln(&format!("{}struct {} {{", vis, name));
cg.indent += 1;
for (field_name, (_, ty)) in &fields.0 {
let ty = self.translate_type(ty);
self.add_indentedln(&format!("pub {}: {},", field_name, ty));
let ty = ty.get_rust(cg);
cg.add_indentedln(&format!("pub {}: {},", field_name, ty));
}
self.indent -= 1;
self.addln("}\n");
cg.indent -= 1;
cg.addln("}\n");
}
TopLevel::FunctionDecl {
@@ -83,7 +217,7 @@ impl RustCodegen {
"{name}{}",
v.type_
.as_ref()
.map(|t| format!(": {}", self.translate_type(t)))
.map(|t| format!(": {}", t.get_rust(cg)))
.unwrap_or_default()
)
})
@@ -92,51 +226,32 @@ impl RustCodegen {
let ret = return_type
.as_ref()
.map(|t| format!(" -> {}", self.translate_type(t)))
.map(|t| format!(" -> {}", t.get_rust(cg)))
.unwrap_or_default();
self.addln(&format!("{}fn {}({}){} {{", vis, name, params_str, ret));
cg.addln(&format!("{}fn {}({}){} {{", vis, name, params_str, ret));
cg.indent += 1;
body.to_rust(cg);
cg.indent -= 1;
cg.addln("}\n");
}
}
}
}
self.indent += 1;
self.generate_block(body);
self.indent -= 1;
self.addln("}\n");
}
}
}
fn translate_type(&self, ty: &TypeExpr) -> String {
match ty {
TypeExpr::Identifier(name) => match name.as_str() {
"int" => "i32".into(),
"float" | "float64" => "f64".into(),
"float32" => "f32".into(),
"bool" => "bool".into(),
"string" => "String".into(),
_ => name.clone(),
},
}
}
fn generate_block(&mut self, block: &Block) {
for stmt in &block.0 {
self.generate_statement(stmt);
}
}
fn generate_statement(&mut self, stmt: &Statement) {
match stmt {
impl ToRust for Statement {
fn to_rust(&self, cg: &mut RustCodegen) {
match self {
Statement::Expression(expr) => {
self.add_indentedln(&format!("{};", self.generate_expression(expr)));
cg.add_indentedln(&format!("{};", expr.get_rust(cg)));
}
Statement::Block(block) => {
self.add_indentedln("{");
self.indent += 1;
self.generate_block(block);
self.indent -= 1;
self.add_indentedln("}");
cg.add_indentedln("{");
cg.indent += 1;
block.to_rust(cg);
cg.indent -= 1;
cg.add_indentedln("}");
}
Statement::VarDecl(VarDeclStmt { decl, init }) => {
@@ -145,22 +260,22 @@ impl RustCodegen {
let ty = decl
.type_
.as_ref()
.map(|t| format!(": {}", self.translate_type(t)))
.map(|t| format!(": {}", t.get_rust(cg)))
.unwrap_or_default();
let init = init
.as_ref()
.map(|e| format!(" = {}", self.generate_expression(e)))
.map(|e| format!(" = {}", e.get_rust(cg)))
.unwrap_or_default();
self.add_indentedln(&format!("let {}{}{}{};", mutability, decl.name, ty, init));
cg.add_indentedln(&format!("let {}{}{}{};", mutability, decl.name, ty, init));
}
Statement::VarAssign(VarAssignStmt { target, value }) => {
self.add_indentedln(&format!(
cg.add_indentedln(&format!(
"{} = {};",
self.generate_expression(target),
self.generate_expression(value)
target.get_rust(cg),
value.get_rust(cg),
));
}
@@ -169,122 +284,40 @@ impl RustCodegen {
then_branch,
else_branch,
}) => {
self.add_indentedln(&format!("if {} {{", self.generate_expression(condition)));
self.indent += 1;
self.generate_statement(then_branch);
self.indent -= 1;
self.add_indentedln("}");
cg.add_indentedln(&format!("if {} {{", condition.get_rust(cg)));
cg.indent += 1;
then_branch.to_rust(cg);
cg.indent -= 1;
cg.add_indentedln("}");
if let Some(else_br) = else_branch {
self.add_indentedln("else {");
self.indent += 1;
self.generate_statement(else_br);
self.indent -= 1;
self.add_indentedln("}");
cg.add_indentedln("else {");
cg.indent += 1;
else_br.to_rust(cg);
cg.indent -= 1;
cg.add_indentedln("}");
}
}
Statement::While(WhileStmt { condition, body }) => {
self.add_indentedln(&format!("while {} {{", self.generate_expression(condition)));
self.indent += 1;
self.generate_statement(body);
self.indent -= 1;
self.add_indentedln("}");
cg.add_indentedln(&format!("while {} {{", condition.get_rust(cg)));
cg.indent += 1;
body.to_rust(cg);
cg.indent -= 1;
cg.add_indentedln("}");
}
Statement::For { .. } => {
// Rust doesn't support C-style for loops
self.add_indentedln("// TODO: transform into iterator-based loop");
cg.add_indentedln("// TODO: transform into iterator-based loop");
}
Statement::Return(expr) => {
let val = expr
.as_ref()
.map(|e| self.generate_expression(e))
.unwrap_or_default();
self.add_indentedln(&format!("return {};", val));
let val = expr.as_ref().map(|e| e.get_rust(cg)).unwrap_or_default();
cg.add_indentedln(&format!("return {};", val));
}
Statement::Break => self.add_indentedln("break;"),
Statement::Continue => self.add_indentedln("continue;"),
Statement::Break => cg.add_indentedln("break;"),
Statement::Continue => cg.add_indentedln("continue;"),
}
}
fn generate_expression(&self, expr: &Expression) -> String {
match expr {
Expression::Identifier(name) => name.clone(),
Expression::IntLiteral(n) => n.to_string(),
Expression::FloatLiteral(n) => n.to_string(),
Expression::BoolLiteral(b) => b.to_string(),
Expression::StringLiteral(s) => format!("\"{}\".to_string()", s),
Expression::Postfix { initial, postfixes } => {
let base = self.generate_expression(initial);
self.apply_postfixes(&base, postfixes)
}
}
}
fn apply_postfixes(&self, base: &str, postfixes: &[Postfix]) -> String {
let mut result = base.to_string();
for postfix in postfixes {
result = match postfix {
Postfix::FieldAccess(field) => format!("{}.{}", result, field),
Postfix::Call(args) => {
let args = args
.iter()
.map(|a| self.generate_expression(a))
.collect::<Vec<_>>()
.join(", ");
format!("{}({})", result, args)
}
Postfix::StructCall(fields) => {
let fields = fields
.iter()
.map(|(k, v)| format!("{}: {}", k, self.generate_expression(v)))
.collect::<Vec<_>>()
.join(", ");
format!("{} {{ {} }}", result, fields)
}
Postfix::Index(idx) => {
format!("{}[{}]", result, self.generate_expression(idx))
}
Postfix::Binary(op, rhs) => {
let op = match op {
BinaryOp::Plus => "+",
BinaryOp::Minus => "-",
BinaryOp::Multiply => "*",
BinaryOp::Divide => "/",
BinaryOp::Modulo => "%",
BinaryOp::Equal => "==",
BinaryOp::NotEqual => "!=",
BinaryOp::LessThan => "<",
BinaryOp::GreaterThan => ">",
BinaryOp::LessThanOrEqual => "<=",
BinaryOp::GreaterThanOrEqual => ">=",
};
format!("{} {} {}", result, op, self.generate_expression(rhs))
}
};
}
result
}
}
impl Default for RustCodegen {
fn default() -> Self {
Self::new()
}
}