diff options
| -rw-r--r-- | src/grammar.pest | 2 | ||||
| -rw-r--r-- | src/main.rs | 251 |
2 files changed, 100 insertions, 153 deletions
diff --git a/src/grammar.pest b/src/grammar.pest index 822e256..000ddd5 100644 --- a/src/grammar.pest +++ b/src/grammar.pest @@ -1,7 +1,7 @@ COMMENT = _{ "#" ~ (!("#" | NEWLINE) ~ ANY)* ~ NEWLINE* } WHITESPACE = _{ " " | "\t" | NEWLINE } program = { SOI ~ statement+ ~ EOI } -statement = { (definition | expression)} +statement = { (definition | expression) } definition = { symbol ~ "=" ~ expression ~ ";"+ } expression = { (symbol | integer_literal | string_literal | ("(" ~ expression ~ ")"))+ } integer_literal = @{ "-"? ~ ASCII_DIGIT+ } diff --git a/src/main.rs b/src/main.rs index 41b4422..add9f5e 100644 --- a/src/main.rs +++ b/src/main.rs @@ -1,8 +1,6 @@ #[macro_use] extern crate pest_derive; -extern crate from_pest; #[macro_use] -extern crate pest_ast; extern crate pest; mod parser { @@ -11,173 +9,122 @@ mod parser { pub struct Parser; } -// mod ast { -// use super::parser::Rule; -// use pest::Span; +mod ast { + use super::parser::Rule; + use pest::Span; -// fn span_into_str(span: Span) -> &str { -// span.as_str() -// } + fn span_into_str(span: Span) -> &str { + span.as_str() + } -// #[derive(Debug, FromPest)] -// #[pest_ast(rule(Rule::program))] -// pub struct Program { -// pub statements: Vec<Statement>, -// pub eoi: EOI, -// } + pub fn from_parse_tree(parse_tree: &mut pest::iterators::Pairs<Rule>) -> Program { + let root = parse_tree.next().unwrap(); -// #[derive(Debug, FromPest)] -// #[pest_ast(rule(Rule::statement))] -// pub enum Statement { -// Definition(Definition), -// Expression(Expression), -// } + match root.as_rule() { + Rule::program => { + let statements_with_eoi: Vec<pest::iterators::Pair<Rule>> = + root.into_inner().collect(); + let statements_split = statements_with_eoi.split_last().unwrap(); + let statements = statements_split.1.to_vec(); -// #[derive(Debug, FromPest)] -// #[pest_ast(rule(Rule::definition))] -// pub struct Definition { -// pub symbols: Vec<Symbol>, -// pub expression: Expression, -// } + statements + .iter() + .map(|s| Statement::from_pair(s.clone())) + .collect() + } + _ => panic!("[ast] first Pair is not a program"), + } + } -// #[derive(Debug, FromPest, Clone)] -// #[pest_ast(rule(Rule::expression))] -// pub enum Expression { -// IntegerLiteral(IntegerLiteral), -// Symbol(Symbol), -// SubExpressions(Vec<Expression>), -// } + pub type Program = Vec<Statement>; -// #[derive(Debug, FromPest, Copy, Clone)] -// #[pest_ast(rule(Rule::integer_literal))] -// pub struct IntegerLiteral { -// #[pest_ast(outer(with(span_into_str), with(str::parse::<i64>), with(Result::unwrap)))] -// pub value: i64, -// } + #[derive(Debug)] + pub enum Statement { + Definition { + symbol: Symbol, + expression: Expression, + }, + Expression(Expression), + } -// #[derive(Debug, FromPest, Clone)] -// #[pest_ast(rule(Rule::symbol))] -// pub struct Symbol { -// #[pest_ast(outer(with(span_into_str), with(String::from)))] -// pub value: String, -// } + impl Statement { + fn from_pair(pair: pest::iterators::Pair<Rule>) -> Statement { + // println!("Statement::from_pair pair: {:#?}", pair); + let def_or_expr = pair.into_inner().next().unwrap(); -// #[derive(Debug, FromPest, Copy, Clone)] -// #[pest_ast(rule(Rule::EOI))] -// pub struct EOI; -// } + fn definition_from_pair(pair: pest::iterators::Pair<Rule>) -> Statement { + let mut inner = pair.into_inner(); + let symbol = inner.next().unwrap().as_span().as_str(); + let expression = inner.next().unwrap(); + let expression_inners: Vec<ExpressionInner> = expression + .into_inner() + .map(ExpressionInner::from_pair) + .collect(); -// mod ir { -// use super::ast; + Statement::Definition { + symbol: String::from(symbol), + expression: expression_inners, + } + } -// pub fn left_associate_exprs(program: &ast::Program) -> ast::Program { -// fn associate(expr: &ast::Expression) -> ast::Expression { -// match expr.nodes.len() { -// 1 | 2 => expr.clone(), -// 3.. => { -// let inner_node = ast::ExpressionNode::SubNodes(expr.nodes[0..2].to_vec()); -// let rest = expr.nodes[2..].to_vec(); -// let mut new_nodes = vec![inner_node]; -// new_nodes.extend(rest); -// let outer_node = ast::Expression { nodes: new_nodes }; -// associate(&outer_node) -// } -// _ => unreachable!(), -// } -// } + match def_or_expr.as_rule() { + Rule::definition => definition_from_pair(def_or_expr), + Rule::expression => { + let expression_inners: Vec<ExpressionInner> = def_or_expr + .into_inner() + .map(ExpressionInner::from_pair) + .collect(); + Statement::Expression(expression_inners) + } + rule => panic!("[ast] can't make a statement from {:#?}", rule), + } + } + } -// let statements = program -// .statements -// .iter() -// .map(|s| match s { -// ast::Statement::Expression(expr) => ast::Statement::Expression(associate(expr)), -// ast::Statement::Definition(def) => ast::Statement::Definition(ast::Definition { -// symbols: def.symbols.clone(), -// expression: associate(&def.expression), -// }), -// }) -// .collect(); + #[derive(Debug)] + pub enum ExpressionInner { + Symbol(Symbol), + IntegerLiteral(IntegerLiteral), + StringLiteral(StringLiteral), + Expression(Expression), + } -// ast::Program { -// statements, -// eoi: program.eoi.clone(), -// } -// } -// } + impl ExpressionInner { + fn from_pair(pair: pest::iterators::Pair<Rule>) -> ExpressionInner { + // println!("ExpressionInner::from_pair pair: {:#?}", pair); -// mod runtime { -// use super::ast; -// use std::collections::HashMap; -// use std::rc::Rc; + match pair.as_rule() { + Rule::symbol => ExpressionInner::Symbol(string_from_pair(pair)), + Rule::integer_literal => ExpressionInner::IntegerLiteral(integer_from_pair(pair)), + Rule::string_literal => ExpressionInner::StringLiteral(string_from_pair(pair)), + Rule::expression => { + let expression_inners: Vec<ExpressionInner> = + pair.into_inner().map(ExpressionInner::from_pair).collect(); + ExpressionInner::Expression(expression_inners) + } + rule => panic!("[ast] can't make an expression element from {:#?}", rule), + } + } + } -// #[derive(Debug)] -// pub enum BuiltinFn { -// Const(i64), -// } + pub type Expression = Vec<ExpressionInner>; -// #[derive(Debug)] -// pub enum Function { -// Builtin(BuiltinFn), -// } + pub type IntegerLiteral = i64; + fn integer_from_pair(pair: pest::iterators::Pair<Rule>) -> i64 { + let s = pair.as_span().as_str(); + s.parse().unwrap() + } -// pub fn evaluate(ast: &ast::Program) { -// let mut symbol_table: HashMap<String, Rc<Function>> = HashMap::new(); + pub type StringLiteral = String; + fn string_from_pair(pair: pest::iterators::Pair<Rule>) -> String { + String::from(pair.as_span().as_str()) + } -// // symbol_table.insert(String::from("const")); - -// // fn apply_function(function: &Function, arg: &Function) -> Function { -// // match function { -// // Function::Builtin(builtin_fn) => match builtin_fn { -// // BuiltinFn::Const(value) => Function::Builtin(BuiltinFn::Const(*value)), -// // }, -// // } -// // } - -// fn evaluate_nonary( -// table: &HashMap<String, Rc<Function>>, -// lhs: &ast::ExpressionNode, -// ) -> Rc<Function> { -// match lhs { -// ast::ExpressionNode::IntegerLiteral(literal) => { -// Rc::new(Function::Builtin(BuiltinFn::Const(literal.value))) -// } -// ast::ExpressionNode::Symbol(symbol) => match symbol.value.as_str() { -// "math-zero" => Rc::new(Function::Builtin(BuiltinFn::Const(0))), -// sym => (*table.get(sym).expect("symbol not found")).clone(), -// }, -// _ => todo!("_ case in evaluate_nonary"), -// } -// } - -// fn evaluate_unary( -// table: &HashMap<String, Rc<Function>>, -// lhs: &ast::ExpressionNode, -// rhs: &ast::ExpressionNode, -// ) -> Rc<Function> { -// let rhs_evaled = evaluate_nonary(&table, rhs); -// todo!("evaluate_unary") -// } - -// for statement in &ast.statements { -// let res: Rc<Function> = match statement { -// ast::Statement::Expression(expression) => match expression.nodes.len() { -// 1 => evaluate_nonary(&symbol_table, &expression.nodes[0]), -// 2 => evaluate_unary(&symbol_table, &expression.nodes[0], &expression.nodes[1]), -// _ => unreachable!("expr arity > 2"), -// }, -// ast::Statement::Definition(_) => { -// panic!("unsupported statement type: definition") -// } -// }; - -// println!("Result: {:#?}", res) -// } -// } -// } + pub type Symbol = String; +} fn main() { - // use ast::Program; - use from_pest::FromPest; + use ast::Program; use pest::Parser; use std::fs; @@ -186,8 +133,8 @@ fn main() { parser::Parser::parse(parser::Rule::program, &unparsed_file).expect("unsuccessful parse"); println!("parse tree = {:#?}", parse_tree); - // let syntax_tree: Program = Program::from_pest(&mut parse_tree).expect("infallible"); - // println!("syntax tree = {:#?}", syntax_tree); + let syntax_tree: Program = ast::from_parse_tree(&mut parse_tree); + println!("syntax tree = {:#?}", syntax_tree); // let ir_tree = ir::left_associate_exprs(&syntax_tree); // println!("ir tree = {:#?}", ir_tree); |