Mist Script

This commit is contained in:
2026-04-22 15:03:34 +02:00
parent bd262f98f8
commit 27a772dad8
6 changed files with 400 additions and 465 deletions
+1 -388
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@@ -1,389 +1,2 @@
use std::collections::HashMap;
use pest::Parser;
use pest_derive::Parser;
pub mod ast;
use ast::*;
#[derive(Parser)]
#[grammar = "./src/grammar.pest"]
pub struct MistParser;
// convenience alias for pest errors
pub type ParseError = pest::error::Error<Rule>;
pub fn parse(source: &str) -> Result<Vec<TopLevel>, ParseError> {
let mut pairs = MistParser::parse(Rule::program, source)?;
let mut statements = vec![];
for pair in pairs.next().unwrap().into_inner() {
if let Some(stmt) = TopLevel::from_pair(pair) {
statements.push(stmt);
}
}
Ok(statements)
}
impl TypeExpr {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::type_expr => {
let inner = pair.into_inner().next().unwrap();
TypeExpr::from_pair(inner)
}
Rule::identifier => TypeExpr::Identifier(pair.as_str().to_string()),
_ => unimplemented!("TypeExpr parsing not implemented yet"),
}
}
}
impl ParamList {
pub fn from_pair(export_allowed: bool, pair: pest::iterators::Pair<Rule>) -> Self {
let params = pair
.into_inner()
.map(|p| {
let mut param_inner = p.into_inner();
let export =
if export_allowed && param_inner.peek().unwrap().as_rule() == Rule::export {
param_inner.next().unwrap();
true
} else {
false
};
let param_name = param_inner.next().unwrap().as_str().to_string();
let param_type = TypeExpr::from_pair(param_inner.next().unwrap());
(param_name, (export, param_type))
})
.collect();
ParamList(params)
}
}
impl TopLevel {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Option<Self> {
match pair.as_rule() {
Rule::import => {
let path = pair.into_inner().next().unwrap().as_str().to_string();
Some(TopLevel::Import(path))
}
Rule::package => {
let name = pair.into_inner().next().unwrap().as_str().to_string();
Some(TopLevel::Package(name))
}
Rule::function_decl => {
let mut inner = pair.into_inner();
let export = if let Some(first) = inner.peek() {
if first.as_rule() == Rule::export {
inner.next();
true
} else {
false
}
} else {
false
};
let name = inner.next().unwrap().as_str().to_string();
let params = if inner.peek().unwrap().as_rule() == Rule::param_list {
ParamList::from_pair(false, inner.next().unwrap())
} else {
ParamList(HashMap::new())
};
let return_type = if let Some(next) = inner.peek() {
if next.as_rule() == Rule::type_expr {
Some(TypeExpr::from_pair(inner.next().unwrap()))
} else {
None
}
} else {
None
};
let body = Block::from_pair(inner.next().unwrap());
Some(TopLevel::FunctionDecl {
export,
name,
params,
return_type,
body,
})
}
Rule::struct_decl => {
let mut inner = pair.into_inner();
let export = if let Some(first) = inner.peek() {
if first.as_rule() == Rule::export {
inner.next();
true
} else {
false
}
} else {
false
};
let name = inner.next().unwrap().as_str().to_string();
let fields_pair = inner.next().unwrap();
let fields = ParamList::from_pair(true, fields_pair);
Some(TopLevel::StructDecl {
export,
name,
fields,
})
}
Rule::EOI => None,
_ => unimplemented!("TopLevel parsing not implemented yet {:?}", pair.as_rule()),
}
}
}
impl Block {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
let statements = pair
.into_inner()
.flat_map(|pair| {
if pair.as_rule() == Rule::statement_list {
pair.into_inner().map(Statement::from_pair).collect()
} else {
vec![Statement::from_pair(pair)]
}
})
.collect();
Block(statements)
}
}
impl Statement {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::statement => {
let inner = pair.into_inner().next().unwrap();
Statement::from_pair(inner)
}
Rule::expr_stmt => {
let expr_pair = pair.into_inner().next().unwrap();
Statement::Expression(Expression::from_pair(expr_pair))
}
Rule::block => Statement::Block(Block::from_pair(pair.into_inner().next().unwrap())),
Rule::var_decl => {
let mut inner = pair.into_inner();
let kind_pair = inner.next().unwrap(); // let/const/var
let name_pair = inner.next().unwrap(); // identifier
let init = inner.next().map(Expression::from_pair);
let kind = match kind_pair.as_str() {
"let" => VarKind::Let,
"const" => VarKind::Const,
"var" => VarKind::Var,
_ => unreachable!(),
};
Statement::VarDecl {
kind,
name: name_pair.as_str().to_string(),
init,
}
}
Rule::return_stmt => {
let mut inner = pair.into_inner();
let expr = inner.next().map(Expression::from_pair);
Statement::Return(expr)
}
Rule::break_stmt => Statement::Break,
Rule::continue_stmt => Statement::Continue,
Rule::if_stmt => {
let mut inner = pair.into_inner();
let condition = Expression::from_pair(inner.next().unwrap());
let then_branch = Statement::from_pair(inner.next().unwrap());
let else_branch = inner.next().map(Statement::from_pair);
Statement::If {
condition,
then_branch: Box::new(then_branch),
else_branch: else_branch.map(Box::new),
}
}
Rule::while_stmt => {
let mut inner = pair.into_inner();
let condition = Expression::from_pair(inner.next().unwrap());
let body = Statement::from_pair(inner.next().unwrap());
Statement::While {
condition,
body: Box::new(body),
}
}
Rule::for_stmt => {
let mut inner = pair.into_inner();
let init = inner
.next()
.map(|p| match p.as_rule() {
Rule::var_decl => {
let mut it = p.into_inner();
let kind = match it.next().unwrap().as_str() {
"let" => VarKind::Let,
"const" => VarKind::Const,
"var" => VarKind::Var,
_ => unreachable!(),
};
let name = it.next().unwrap().as_str().to_string();
let init_expr = it
.next()
.map(|e| Expression::from_pair(e.into_inner().next().unwrap()));
(kind, name, init_expr)
}
_ => unimplemented!(
"For loop init parsing not implemented yet: {:?}",
p.as_rule()
),
})
.unwrap();
let condition = inner.next().map(Expression::from_pair);
let update = inner.next().map(parse_var_assign_no_semicolon);
let body = Statement::from_pair(inner.next().unwrap());
Statement::For {
init,
condition,
update: update.map(Box::new),
body: Box::new(body),
}
}
Rule::var_assign => {
let mut inner = pair.into_inner();
let target = Expression::from_pair(inner.next().unwrap());
let value = Expression::from_pair(inner.next().unwrap());
Statement::VarAssign { target, value }
}
_ => unimplemented!(
"Statement parsing not implemented yet: {:?}",
pair.as_rule()
),
}
}
}
impl Expression {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::expr => {
let mut inner = pair.into_inner();
let exp = Expression::from_pair(inner.next().unwrap());
if inner.len() > 0 {
Expression::Postfix {
initial: Box::new(exp),
postfixes: inner.map(|p| Postfix::from_pair(p)).collect(),
}
} else {
exp
}
}
Rule::primary => Expression::from_pair(pair.into_inner().next().unwrap()),
Rule::identifier => Expression::Identifier(pair.as_str().to_string()),
Rule::integer => {
let value = pair.as_str().parse::<i64>().unwrap();
Expression::IntLiteral(value)
}
Rule::float => {
let value = pair.as_str().parse::<f64>().unwrap();
Expression::FloatLiteral(value)
}
Rule::boolean => {
let value = pair.as_str().parse::<bool>().unwrap();
Expression::BoolLiteral(value)
}
Rule::string_lit => {
let inner_str = pair.into_inner().next().unwrap().as_str();
Expression::StringLiteral(inner_str.to_string())
}
_ => unimplemented!(
"Expression parsing not implemented yet {:?}",
pair.as_rule()
),
}
}
}
impl Postfix {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::postfix => Postfix::from_pair(pair.into_inner().next().unwrap()),
Rule::field_px => {
let field_name = pair.into_inner().next().unwrap().as_str().to_string();
Postfix::FieldAccess(field_name)
}
Rule::call_px => Postfix::Call(pair.into_inner().map(Expression::from_pair).collect()),
Rule::index_px => {
Postfix::Index(Expression::from_pair(pair.into_inner().next().unwrap()))
}
Rule::binary_px => {
let mut inner = pair.into_inner();
let op_pair = inner.next().unwrap();
let op = match op_pair.as_str() {
"+" => BinaryOp::Plus,
"-" => BinaryOp::Minus,
"*" => BinaryOp::Multiply,
"/" => BinaryOp::Divide,
"%" => BinaryOp::Modulo,
"==" => BinaryOp::Equal,
"!=" => BinaryOp::NotEqual,
"<" => BinaryOp::LessThan,
">" => BinaryOp::GreaterThan,
"<=" => BinaryOp::LessThanOrEqual,
">=" => BinaryOp::GreaterThanOrEqual,
_ => {
unimplemented!("Binary operator not implemented yet: {}", op_pair.as_str())
}
};
Postfix::Binary(op, Expression::from_pair(inner.next().unwrap()))
}
_ => unimplemented!("Postfix parsing not implemented yet {:?}", pair.as_rule()),
}
}
}
fn parse_var_assign_no_semicolon(pair: pest::iterators::Pair<Rule>) -> Statement {
let mut inner = pair.into_inner();
let target = Expression::from_pair(inner.next().unwrap());
let value = Expression::from_pair(inner.next().unwrap());
Statement::VarAssign { target, value }
}
pub mod script_parser;
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use std::collections::HashMap;
use pest::Parser;
use pest_derive::Parser;
use crate::ast::*;
#[derive(Parser)]
#[grammar = "./src/script_grammar.pest"]
pub struct MistParser;
// convenience alias for pest errors
pub type ParseError = pest::error::Error<Rule>;
pub fn parse(source: &str) -> Result<Vec<TopLevel>, ParseError> {
let mut pairs = MistParser::parse(Rule::program, source)?;
let mut statements = vec![];
for pair in pairs.next().unwrap().into_inner() {
if let Some(stmt) = TopLevel::from_pair(pair) {
statements.push(stmt);
}
}
Ok(statements)
}
impl TypeExpr {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::type_expr => {
let inner = pair.into_inner().next().unwrap();
TypeExpr::from_pair(inner)
}
Rule::identifier => TypeExpr::Identifier(pair.as_str().to_string()),
_ => unimplemented!("TypeExpr parsing not implemented yet"),
}
}
}
impl ParamList {
pub fn from_pair(export_allowed: bool, pair: pest::iterators::Pair<Rule>) -> Self {
let params = pair
.into_inner()
.map(|p| {
let mut param_inner = p.into_inner();
let export =
if export_allowed && param_inner.peek().unwrap().as_rule() == Rule::export {
param_inner.next().unwrap();
true
} else {
false
};
let param_name = param_inner.next().unwrap().as_str().to_string();
let param_type = TypeExpr::from_pair(param_inner.next().unwrap());
(param_name, (export, param_type))
})
.collect();
ParamList(params)
}
}
impl TopLevel {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Option<Self> {
match pair.as_rule() {
Rule::import => {
let path = pair.into_inner().next().unwrap().as_str().to_string();
Some(TopLevel::Import(path))
}
Rule::package => {
let name = pair.into_inner().next().unwrap().as_str().to_string();
Some(TopLevel::Package(name))
}
Rule::function_decl => {
let mut inner = pair.into_inner();
let export = if let Some(first) = inner.peek() {
if first.as_rule() == Rule::export {
inner.next();
true
} else {
false
}
} else {
false
};
let name = inner.next().unwrap().as_str().to_string();
let params = if inner.peek().unwrap().as_rule() == Rule::param_list {
ParamList::from_pair(false, inner.next().unwrap())
} else {
ParamList(HashMap::new())
};
let return_type = if let Some(next) = inner.peek() {
if next.as_rule() == Rule::type_expr {
Some(TypeExpr::from_pair(inner.next().unwrap()))
} else {
None
}
} else {
None
};
let body = Block::from_pair(inner.next().unwrap());
Some(TopLevel::FunctionDecl {
export,
name,
params,
return_type,
body,
})
}
Rule::struct_decl => {
let mut inner = pair.into_inner();
let export = if let Some(first) = inner.peek() {
if first.as_rule() == Rule::export {
inner.next();
true
} else {
false
}
} else {
false
};
let name = inner.next().unwrap().as_str().to_string();
let fields_pair = inner.next().unwrap();
let fields = ParamList::from_pair(true, fields_pair);
Some(TopLevel::StructDecl {
export,
name,
fields,
})
}
Rule::EOI => None,
_ => unimplemented!("TopLevel parsing not implemented yet {:?}", pair.as_rule()),
}
}
}
impl Block {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
let statements = pair
.into_inner()
.flat_map(|pair| {
if pair.as_rule() == Rule::statement_list {
pair.into_inner().map(Statement::from_pair).collect()
} else {
vec![Statement::from_pair(pair)]
}
})
.collect();
Block(statements)
}
}
impl Statement {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::statement => {
let inner = pair.into_inner().next().unwrap();
Statement::from_pair(inner)
}
Rule::expr_stmt => {
let expr_pair = pair.into_inner().next().unwrap();
Statement::Expression(Expression::from_pair(expr_pair))
}
Rule::block => Statement::Block(Block::from_pair(pair.into_inner().next().unwrap())),
Rule::var_decl => {
let mut inner = pair.into_inner();
let kind_pair = inner.next().unwrap(); // let/const/var
let name_pair = inner.next().unwrap(); // identifier
let init = inner.next().map(Expression::from_pair);
let kind = match kind_pair.as_str() {
"let" => VarKind::Let,
"const" => VarKind::Const,
"var" => VarKind::Var,
_ => unreachable!(),
};
Statement::VarDecl {
kind,
name: name_pair.as_str().to_string(),
init,
}
}
Rule::return_stmt => {
let mut inner = pair.into_inner();
let expr = inner.next().map(Expression::from_pair);
Statement::Return(expr)
}
Rule::break_stmt => Statement::Break,
Rule::continue_stmt => Statement::Continue,
Rule::if_stmt => {
let mut inner = pair.into_inner();
let condition = Expression::from_pair(inner.next().unwrap());
let then_branch = Statement::from_pair(inner.next().unwrap());
let else_branch = inner.next().map(Statement::from_pair);
Statement::If {
condition,
then_branch: Box::new(then_branch),
else_branch: else_branch.map(Box::new),
}
}
Rule::while_stmt => {
let mut inner = pair.into_inner();
let condition = Expression::from_pair(inner.next().unwrap());
let body = Statement::from_pair(inner.next().unwrap());
Statement::While {
condition,
body: Box::new(body),
}
}
Rule::for_stmt => {
let mut inner = pair.into_inner();
let init = inner
.next()
.map(|p| match p.as_rule() {
Rule::var_decl => {
let mut it = p.into_inner();
let kind = match it.next().unwrap().as_str() {
"let" => VarKind::Let,
"const" => VarKind::Const,
"var" => VarKind::Var,
_ => unreachable!(),
};
let name = it.next().unwrap().as_str().to_string();
let init_expr = it
.next()
.map(|e| Expression::from_pair(e.into_inner().next().unwrap()));
(kind, name, init_expr)
}
_ => unimplemented!(
"For loop init parsing not implemented yet: {:?}",
p.as_rule()
),
})
.unwrap();
let condition = inner.next().map(Expression::from_pair);
let update = inner.next().map(parse_var_assign_no_semicolon);
let body = Statement::from_pair(inner.next().unwrap());
Statement::For {
init,
condition,
update: update.map(Box::new),
body: Box::new(body),
}
}
Rule::var_assign => {
let mut inner = pair.into_inner();
let target = Expression::from_pair(inner.next().unwrap());
let value = Expression::from_pair(inner.next().unwrap());
Statement::VarAssign { target, value }
}
_ => unimplemented!(
"Statement parsing not implemented yet: {:?}",
pair.as_rule()
),
}
}
}
impl Expression {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::expr => {
let mut inner = pair.into_inner();
let exp = Expression::from_pair(inner.next().unwrap());
if inner.len() > 0 {
Expression::Postfix {
initial: Box::new(exp),
postfixes: inner.map(|p| Postfix::from_pair(p)).collect(),
}
} else {
exp
}
}
Rule::primary => Expression::from_pair(pair.into_inner().next().unwrap()),
Rule::identifier => Expression::Identifier(pair.as_str().to_string()),
Rule::integer => {
let value = pair.as_str().parse::<i64>().unwrap();
Expression::IntLiteral(value)
}
Rule::float => {
let value = pair.as_str().parse::<f64>().unwrap();
Expression::FloatLiteral(value)
}
Rule::boolean => {
let value = pair.as_str().parse::<bool>().unwrap();
Expression::BoolLiteral(value)
}
Rule::string_lit => {
let inner_str = pair.into_inner().next().unwrap().as_str();
Expression::StringLiteral(inner_str.to_string())
}
_ => unimplemented!(
"Expression parsing not implemented yet {:?}",
pair.as_rule()
),
}
}
}
impl Postfix {
pub fn from_pair(pair: pest::iterators::Pair<Rule>) -> Self {
match pair.as_rule() {
Rule::postfix => Postfix::from_pair(pair.into_inner().next().unwrap()),
Rule::field_px => {
let field_name = pair.into_inner().next().unwrap().as_str().to_string();
Postfix::FieldAccess(field_name)
}
Rule::call_px => Postfix::Call(pair.into_inner().map(Expression::from_pair).collect()),
Rule::index_px => {
Postfix::Index(Expression::from_pair(pair.into_inner().next().unwrap()))
}
Rule::binary_px => {
let mut inner = pair.into_inner();
let op_pair = inner.next().unwrap();
let op = match op_pair.as_str() {
"+" => BinaryOp::Plus,
"-" => BinaryOp::Minus,
"*" => BinaryOp::Multiply,
"/" => BinaryOp::Divide,
"%" => BinaryOp::Modulo,
"==" => BinaryOp::Equal,
"!=" => BinaryOp::NotEqual,
"<" => BinaryOp::LessThan,
">" => BinaryOp::GreaterThan,
"<=" => BinaryOp::LessThanOrEqual,
">=" => BinaryOp::GreaterThanOrEqual,
_ => {
unimplemented!("Binary operator not implemented yet: {}", op_pair.as_str())
}
};
Postfix::Binary(op, Expression::from_pair(inner.next().unwrap()))
}
_ => unimplemented!("Postfix parsing not implemented yet {:?}", pair.as_rule()),
}
}
}
fn parse_var_assign_no_semicolon(pair: pest::iterators::Pair<Rule>) -> Statement {
let mut inner = pair.into_inner();
let target = Expression::from_pair(inner.next().unwrap());
let value = Expression::from_pair(inner.next().unwrap());
Statement::VarAssign { target, value }
}