schala/schala-lang/language/src/ast.rs
2019-10-15 19:03:27 -07:00

300 lines
6.1 KiB
Rust

use std::rc::Rc;
use crate::derivative::Derivative;
mod walker;
mod visitor;
mod visitor_test;
mod operators;
pub use operators::*;
pub use visitor::ASTVisitor;
pub use walker::walk_ast;
/// An abstract identifier for an AST node
#[derive(Debug, PartialEq, Eq, Hash, Clone)]
pub struct ItemId {
idx: u32,
}
impl ItemId {
fn new(n: u32) -> ItemId {
ItemId { idx: n }
}
}
pub struct ItemIdStore {
last_idx: u32
}
impl ItemIdStore {
pub fn new() -> ItemIdStore {
ItemIdStore { last_idx: 0 }
}
/// Always returns an ItemId with internal value zero
#[cfg(test)]
pub fn new_id() -> ItemId {
ItemId { idx: 0 }
}
/// This limits the size of the AST to 2^32 tree elements
pub fn fresh(&mut self) -> ItemId {
let idx = self.last_idx;
self.last_idx += 1;
ItemId::new(idx)
}
}
#[derive(Derivative, Debug)]
#[derivative(PartialEq)]
pub struct AST {
#[derivative(PartialEq="ignore")]
pub id: ItemId,
pub statements: Vec<Statement>
}
#[derive(Derivative, Debug, Clone)]
#[derivative(PartialEq)]
pub struct Statement {
#[derivative(PartialEq="ignore")]
pub id: ItemId,
pub kind: StatementKind,
}
#[derive(Debug, PartialEq, Clone)]
pub enum StatementKind {
Expression(Expression),
Declaration(Declaration),
Import(ImportSpecifier),
}
pub type Block = Vec<Statement>;
pub type ParamName = Rc<String>;
#[derive(Debug, Derivative, Clone)]
#[derivative(PartialEq)]
pub struct QualifiedName {
#[derivative(PartialEq="ignore")]
pub id: ItemId,
pub components: Vec<Rc<String>>,
}
#[derive(Debug, PartialEq, Clone)]
pub struct FormalParam {
pub name: ParamName,
pub default: Option<Expression>,
pub anno: Option<TypeIdentifier>
}
#[derive(Debug, PartialEq, Clone)]
pub enum Declaration {
FuncSig(Signature),
FuncDecl(Signature, Block),
TypeDecl {
name: TypeSingletonName,
body: TypeBody,
mutable: bool
},
//TODO this needs to be more sophisticated
TypeAlias {
alias: Rc<String>,
original: Rc<String>,
},
Binding {
name: Rc<String>,
constant: bool,
type_anno: Option<TypeIdentifier>,
expr: Expression,
},
Impl {
type_name: TypeIdentifier,
interface_name: Option<TypeSingletonName>,
block: Vec<Declaration>,
},
Interface {
name: Rc<String>,
signatures: Vec<Signature>
}
}
#[derive(Debug, PartialEq, Clone)]
pub struct Signature {
pub name: Rc<String>,
pub operator: bool,
pub params: Vec<FormalParam>,
pub type_anno: Option<TypeIdentifier>,
}
#[derive(Debug, PartialEq, Clone)]
pub struct TypeBody(pub Vec<Variant>);
#[derive(Debug, PartialEq, Clone)]
pub enum Variant {
UnitStruct(Rc<String>),
TupleStruct(Rc<String>, Vec<TypeIdentifier>),
Record {
name: Rc<String>,
members: Vec<(Rc<String>, TypeIdentifier)>,
}
}
#[derive(Debug, Derivative, Clone)]
#[derivative(PartialEq)]
pub struct Expression {
#[derivative(PartialEq="ignore")]
pub id: ItemId,
pub kind: ExpressionKind,
pub type_anno: Option<TypeIdentifier>
}
impl Expression {
pub fn new(id: ItemId, kind: ExpressionKind) -> Expression {
Expression { id, kind, type_anno: None }
}
pub fn with_anno(id: ItemId, kind: ExpressionKind, type_anno: TypeIdentifier) -> Expression {
Expression { id, kind, type_anno: Some(type_anno) }
}
}
#[derive(Debug, PartialEq, Clone)]
pub enum TypeIdentifier {
Tuple(Vec<TypeIdentifier>),
Singleton(TypeSingletonName)
}
#[derive(Debug, PartialEq, Clone)]
pub struct TypeSingletonName {
pub name: Rc<String>,
pub params: Vec<TypeIdentifier>,
}
#[derive(Debug, PartialEq, Clone)]
pub enum ExpressionKind {
NatLiteral(u64),
FloatLiteral(f64),
StringLiteral(Rc<String>),
BoolLiteral(bool),
BinExp(BinOp, Box<Expression>, Box<Expression>),
PrefixExp(PrefixOp, Box<Expression>),
TupleLiteral(Vec<Expression>),
Value(QualifiedName),
NamedStruct {
name: QualifiedName,
fields: Vec<(Rc<String>, Expression)>,
},
Call {
f: Box<Expression>,
arguments: Vec<InvocationArgument>,
},
Index {
indexee: Box<Expression>,
indexers: Vec<Expression>,
},
IfExpression {
discriminator: Option<Box<Expression>>,
body: Box<IfExpressionBody>,
},
WhileExpression {
condition: Option<Box<Expression>>,
body: Block,
},
ForExpression {
enumerators: Vec<Enumerator>,
body: Box<ForBody>,
},
Lambda {
params: Vec<FormalParam>,
type_anno: Option<TypeIdentifier>,
body: Block,
},
ListLiteral(Vec<Expression>),
}
#[derive(Debug, PartialEq, Clone)]
pub enum InvocationArgument {
Positional(Expression),
Keyword {
name: Rc<String>,
expr: Expression,
},
Ignored
}
#[derive(Debug, PartialEq, Clone)]
pub enum IfExpressionBody {
SimpleConditional {
then_case: Block,
else_case: Option<Block>
},
SimplePatternMatch {
pattern: Pattern,
then_case: Block,
else_case: Option<Block>
},
CondList(Vec<ConditionArm>)
}
#[derive(Debug, PartialEq, Clone)]
pub struct ConditionArm {
pub condition: Condition,
pub guard: Option<Expression>,
pub body: Block,
}
#[derive(Debug, PartialEq, Clone)]
pub enum Condition {
Pattern(Pattern),
TruncatedOp(BinOp, Expression),
Expression(Expression),
Else,
}
#[derive(Debug, PartialEq, Clone)]
pub enum Pattern {
Ignored,
TuplePattern(Vec<Pattern>),
Literal(PatternLiteral),
TupleStruct(QualifiedName, Vec<Pattern>),
Record(QualifiedName, Vec<(Rc<String>, Pattern)>),
VarOrName(QualifiedName),
}
#[derive(Debug, PartialEq, Clone)]
pub enum PatternLiteral {
NumPattern {
neg: bool,
num: ExpressionKind,
},
StringPattern(Rc<String>),
BoolPattern(bool),
}
#[derive(Debug, PartialEq, Clone)]
pub struct Enumerator {
pub id: Rc<String>,
pub generator: Expression,
}
#[derive(Debug, PartialEq, Clone)]
pub enum ForBody {
MonadicReturn(Expression),
StatementBlock(Block),
}
#[derive(Debug, Derivative, Clone)]
#[derivative(PartialEq)]
pub struct ImportSpecifier {
#[derivative(PartialEq="ignore")]
pub id: ItemId,
pub path_components: Vec<Rc<String>>,
pub imported_names: ImportedNames
}
#[derive(Debug, PartialEq, Clone)]
pub enum ImportedNames {
All,
LastOfPath,
List(Vec<Rc<String>>)
}