79 lines
1.8 KiB
Rust
79 lines
1.8 KiB
Rust
use std::rc::Rc;
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use parsing::{AST, Expression, Declaration};
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use builtin::{BinOp, PrefixOp};
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#[derive(Debug)]
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pub struct ReducedAST(pub Vec<Stmt>);
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#[derive(Debug)]
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pub enum Stmt {
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Binding {
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name: Rc<String>,
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expr: Expr,
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},
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Expr(Expr),
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}
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#[derive(Debug)]
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pub enum Expr {
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Lit(Lit),
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Func(Func),
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Call {
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f: Func,
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args: Vec<Expr>,
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},
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}
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#[derive(Debug)]
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pub enum Lit {
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Int(u64),
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Float(f64),
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Bool(bool),
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StringLit(Rc<String>),
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}
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#[derive(Debug)]
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pub struct Func {
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params: Vec<Rc<String>>,
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body: Vec<Stmt>,
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}
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pub fn perform_ast_reduction(ast: &AST) -> Result<ReducedAST, String> {
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use parsing::Statement::*;
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let mut output = vec![];
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for statement in ast.0.iter() {
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match statement {
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&ExpressionStatement(ref expr) => output.push(reduce_expr(expr)?),
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&Declaration(ref decl) => output.push(reduce_decl(decl)?),
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}
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}
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Ok(ReducedAST(output))
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}
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fn reduce_expr(expr: &Expression) -> Result<Stmt, String> {
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use parsing::ExpressionType::*;
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let ref input = expr.0;
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let output_expr = match input {
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&IntLiteral(ref n) => Expr::Lit(Lit::Int(*n)),
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&FloatLiteral(ref f) => Expr::Lit(Lit::Float(*f)),
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&StringLiteral(ref s) => Expr::Lit(Lit::StringLit(s.clone())),
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&BoolLiteral(ref b) => Expr::Lit(Lit::Bool(*b)),
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&BinExp(ref binop, ref lhs, ref rhs) => reduce_binop(binop, lhs, rhs)?,
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&PrefixExp(ref op, ref arg) => reduce_prefix(op, arg)?,
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e => return Err(format!("{:?} not implemented in reduction", e))
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};
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Ok(Stmt::Expr(output_expr))
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}
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fn reduce_decl(expr: &Declaration) -> Result<Stmt, String> {
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Ok(Stmt::Expr(Expr::Lit(Lit::Int(0))))
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}
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fn reduce_binop(binop: &BinOp, lhs: &Box<Expression>, rhs: &Box<Expression>) -> Result<Expr, String> {
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Err(format!("NOTDONE"))
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}
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fn reduce_prefix(op: &PrefixOp, arg: &Box<Expression>) -> Result<Expr, String> {
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Err(format!("NOTDONE"))
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}
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