use itertools::Itertools; use std::collections::HashMap; use std::rc::Rc; use std::iter::{Enumerate, Peekable}; use std::vec::IntoIter; use std::str::Chars; #[derive(Debug, PartialEq, Clone)] pub enum TokenType { Newline, Semicolon, LParen, RParen, LSquareBracket, RSquareBracket, LAngleBracket, RAngleBracket, LCurlyBrace, RCurlyBrace, Pipe, Comma, Period, Colon, Underscore, Operator(Rc), DigitGroup(Rc), HexNumberSigil, BinNumberSigil, StrLiteral(Rc), Identifier(Rc), Keyword(Kw), EOF, Error(String), } use self::TokenType::*; #[derive(Debug, Clone, Copy, PartialEq)] pub enum Kw { If, Else, Func, For, Match, Var, Const, Let, In, Return, Alias, Type, SelfType, SelfIdent, Trait, Impl, True, False } use self::Kw::*; lazy_static! { static ref KEYWORDS: HashMap<&'static str, Kw> = hashmap! { "if" => Kw::If, "else" => Kw::Else, "fn" => Kw::Func, "for" => Kw::For, "match" => Kw::Match, "var" => Kw::Var, "const" => Kw::Const, "let" => Kw::Let, "in" => Kw::In, "return" => Kw::Return, "alias" => Kw::Alias, "type" => Kw::Type, "Self" => Kw::SelfType, "self" => Kw::SelfIdent, "trait" => Kw::Trait, "impl" => Kw::Impl, "true" => Kw::True, "false" => Kw::False, }; } #[derive(Debug)] pub struct Token { pub token_type: TokenType, pub offset: usize, } impl Token { pub fn get_error(&self) -> Option<&String> { match self.token_type { TokenType::Error(ref s) => Some(s), _ => None, } } } fn is_digit(c: &char) -> bool { c.is_digit(10) } const OPERATOR_CHARS: [char; 19] = ['!', '$', '%', '&', '*', '+', '-', '.', '/', ':', '<', '>', '=', '?', '@', '^', '|', '~', '`']; fn is_operator(c: &char) -> bool { OPERATOR_CHARS.iter().any(|x| x == c) } type CharIter<'a> = Peekable>>; pub fn tokenize(input: &str) -> Vec { let mut tokens: Vec = Vec::new(); let mut input: CharIter = input.chars().enumerate().peekable(); while let Some((idx, c)) = input.next() { let cur_tok_type = match c { '#' => { if let Some(&(_, '{')) = input.peek() { } else { while let Some((_, c)) = input.next() { if c == '\n' { break; } } } continue; }, c if c.is_whitespace() && c != '\n' => continue, '\n' => Newline, ';' => Semicolon, ':' => Colon, ',' => Comma, '(' => LParen, ')' => RParen, '{' => LCurlyBrace, '}' => RCurlyBrace, '[' => LSquareBracket, ']' => RSquareBracket, '"' => handle_quote(&mut input), c if is_digit(&c) => handle_digit(c, &mut input), c if c.is_alphabetic() || c == '_' => handle_alphabetic(c, &mut input), //TODO I'll probably have to rewrite this if I care about types being uppercase, also type parameterization c if is_operator(&c) => handle_operator(c, &mut input), unknown => Error(format!("Unexpected character: {}", unknown)), }; tokens.push(Token { token_type: cur_tok_type, offset: idx }); } tokens } fn handle_digit(c: char, input: &mut CharIter) -> TokenType { if c == '0' && input.peek().map_or(false, |&(_, c)| { c == 'x' }) { input.next(); HexNumberSigil } else if c == '0' && input.peek().map_or(false, |&(_, c)| { c == 'b' }) { input.next(); BinNumberSigil } else { let mut buf = c.to_string(); buf.extend(input.peeking_take_while(|&(_, ref c)| is_digit(c)).map(|(_, c)| { c })); DigitGroup(Rc::new(buf)) } } fn handle_quote(input: &mut CharIter) -> TokenType { let mut buf = String::new(); loop { match input.next().map(|(_, c)| { c }) { Some('"') => break, Some('\\') => { let next = input.peek().map(|&(_, c)| { c }); if next == Some('n') { input.next(); buf.push('\n') } else if next == Some('"') { input.next(); buf.push('"'); } else if next == Some('t') { input.next(); buf.push('\t'); } }, Some(c) => buf.push(c), None => return TokenType::Error(format!("Unclosed string")), } } TokenType::StrLiteral(Rc::new(buf)) } fn handle_alphabetic(c: char, input: &mut CharIter) -> TokenType { let mut buf = String::new(); buf.push(c); if c == '_' && input.peek().map(|&(_, c)| { !c.is_alphabetic() }).unwrap_or(true) { return TokenType::Underscore } loop { match input.peek().map(|&(_, c)| { c }) { Some(c) if c.is_alphanumeric() => { input.next(); buf.push(c); }, _ => break, } } match KEYWORDS.get(buf.as_str()) { Some(kw) => TokenType::Keyword(kw.clone()), None => TokenType::Identifier(Rc::new(buf)), } } fn handle_operator(c: char, input: &mut CharIter) -> TokenType { match c { '<' | '>' | '|' | '.' => { let ref next = input.peek().map(|&(_, c)| { c }); if !next.map(|n| { is_operator(&n) }).unwrap_or(false) { return match c { '<' => LAngleBracket, '>' => RAngleBracket, '|' => Pipe, '.' => Period, _ => unreachable!(), } } }, _ => (), }; let mut buf = String::new(); buf.push(c); loop { match input.peek().map(|&(_, c)| { c }) { Some(c) if is_operator(&c) => { input.next(); buf.push(c); }, _ => break } } TokenType::Operator(Rc::new(buf)) } #[cfg(test)] mod schala_tokenizer_tests { use super::*; macro_rules! digit { ($ident:expr) => { DigitGroup(Rc::new($ident.to_string())) } } macro_rules! ident { ($ident:expr) => { Identifier(Rc::new($ident.to_string())) } } macro_rules! op { ($ident:expr) => { Operator(Rc::new($ident.to_string())) } } #[test] fn tokens() { let a = tokenize("let a: A = c ++ d"); let token_types: Vec = a.into_iter().map(move |t| t.token_type).collect(); assert_eq!(token_types, vec![Keyword(Let), ident!("a"), Colon, ident!("A"), LAngleBracket, ident!("B"), RAngleBracket, op!("="), ident!("c"), op!("++"), ident!("d")]); } #[test] fn underscores() { let token_types: Vec = tokenize("4_8").into_iter().map(move |t| t.token_type).collect(); assert_eq!(token_types, vec![digit!("4"), Underscore, digit!("8")]); } } /* Schala EBNF Grammar */ /* Terminal productions are in 'single quotes' or UPPERCASE if they are a class * or not representable in ASCII program := (statement delimiter)* EOF delimiter := NEWLINE | ';' statement := expression | declaration declaration := type_declaration | func_declaration | binding_declaration | impl_declaration type_declaration := 'type' type_declaration_body type_declaration_body := 'alias' type_alias | IDENTIFIER '=' type_body type_alias := IDENTIFIER '=' type_name type_body := variant_specifier ('|' variant_specifier)* variant_specifier := IDENTIFIER | IDENTIFIER '{' typed_identifier_list '}' | IDENTIFIER '(' type_name* ')' typed_identifier_list := typed_identifier* typed_identifier := IDENTIFIER type_anno func_declaration := func_signature func_body func_body := ε | '{' (statement delimiter)* '}' func_signature := 'fn' IDENTIFIER formal_param_list func_body formal_param_list := '(' (formal_param ',')* ')' formal_param := IDENTIFIER type_anno+ binding_declaration: 'var' IDENTIFIER '=' expression | 'const' IDENTIFIER '=' expression trait_declaration := 'trait' trait_name decl_block impl_declaration := 'impl' IDENTIFIER decl_block | 'impl' trait_name 'for' IDENTIFIER decl_block decl_block := '{' (func_declaration)* '}' trait_name := IDENTIFIER type_anno := (':' type_name)+ type_name := IDENTIFIER (type_params)* | '(' type_names ')' type_names := ε | type_name (, type_name)* type_params := '<' type_name (, type_name)* '>' expression := precedence_expr type_anno+ precedence_expr := prefix_expr prefix_expr := prefix_op primary prefix_op := '+' | '-' | '!' | '~' primary := literal | paren_expr | if_expr | match_expr | for_expr | identifier_expr paren_expr := LParen paren_inner RParen paren_inner := (expression ',')* identifier_expr := call_expr | index_expr | IDENTIFIER literal := 'true' | 'false' | number_literal | STR_LITERAL if_expr := 'if' expression block else_clause else_clause := ε | 'else' block match_expr := 'match' expression match_body match_body := '{' (match_arm)* '}' match_arm := pattern '=>' expression pattern := identifier //TODO NOT DONE block := '{' (statement)* '}' call_expr := IDENTIFIER '(' expr_list ')' //TODO maybe make this optional? or no, have a bare identifier meant to be used as method taken care of in eval index_expr := '[' (expression (',' (expression)* | ε) ']' expr_list := expression (',' expression)* | ε for_expr := 'for' ... ???? // a float_literal can still be assigned to an int in type-checking number_literal := int_literal | float_literal int_literal = ('0x' | '0b') digits float_literal := digits ('.' digits) digits := (DIGIT_GROUP underscore)+ */ type TokenIter = Peekable>; #[derive(Debug, PartialEq)] pub struct ParseError { pub msg: String, } impl ParseError { fn new(msg: &str) -> ParseResult { Err(ParseError { msg: msg.to_string() }) } } pub type ParseResult = Result; #[derive(Debug)] pub struct ParseRecord { production_name: String, next_token: String, } struct Parser { tokens: TokenIter, parse_record: Vec, } impl Parser { fn new(input: Vec) -> Parser { Parser { tokens: input.into_iter().peekable(), parse_record: vec![] } } fn peek(&mut self) -> TokenType { self.tokens.peek().map(|ref t| { t.token_type.clone() }).unwrap_or(TokenType::EOF) } fn next(&mut self) -> TokenType { self.tokens.next().map(|ref t| { t.token_type.clone() }).unwrap_or(TokenType::EOF) } } macro_rules! expect { ($self:expr, $token_type:pat, $expected_item:expr) => { expect!($self, $token_type if true, $expected_item) }; ($self:expr, $token_type:pat if $cond:expr, $expected_item:expr) => { match $self.peek() { $token_type if $cond => $self.next(), tok => { let msg = format!("Expected {}, got {:?}", $expected_item, tok); return Err(ParseError { msg }) } } } } #[derive(Debug, PartialEq)] pub struct AST(pub Vec); #[derive(Debug, PartialEq, Clone)] pub enum Statement { ExpressionStatement(Expression), Declaration(Declaration), } type ParamName = Rc; type TraitName = Rc; type FormalParam = (ParamName, Option); #[derive(Debug, PartialEq, Clone)] pub enum Declaration { FuncSig(Signature), FuncDecl(Signature, Vec), TypeDecl(Rc, TypeBody), TypeAlias(Rc, Rc), Binding { name: Rc, constant: bool, expr: Expression, }, Impl { type_name: TypeName, trait_name: Option, block: Vec, }, } #[derive(Debug, PartialEq, Clone)] pub struct Signature { name: Rc, params: Vec, type_anno: Option, } #[derive(Debug, PartialEq, Clone)] pub struct TypeBody(pub Vec); #[derive(Debug, PartialEq, Clone)] pub enum Variant { UnitStruct(Rc), TupleStruct(Rc, Vec), Record(Rc, Vec<(Rc, TypeName)>), } #[derive(Debug, PartialEq, Clone)] pub struct Expression(pub ExpressionType, pub Option); #[derive(Debug, PartialEq, Clone)] pub enum TypeName { Tuple(Vec), Singleton { name: Rc, params: Vec, } } #[derive(Debug, PartialEq, Clone)] pub enum ExpressionType { IntLiteral(u64), FloatLiteral(f64), StringLiteral(Rc), BoolLiteral(bool), BinExp(Operation, Box, Box), PrefixExp(Operation, Box), TupleLiteral(Vec), Variable(Rc), Call { name: Rc, params: Vec, }, Index { indexee: Box, indexers: Vec, }, IfExpression(Box, Vec, Option>), MatchExpression(Box, Vec), ForExpression } #[derive(Debug, PartialEq, Clone)] pub struct MatchArm { pat: Pattern, expr: Expression, } #[derive(Debug, PartialEq, Clone)] pub struct Pattern(Rc); #[derive(Debug, PartialEq, Clone)] pub struct Operation(pub Rc); impl Operation { fn min_precedence() -> i32 { i32::min_value() } fn get_precedence(op: &str) -> i32 { match op { "+" | "-" => 10, "*" | "/" | "%" => 20, _ => 30, } } fn is_prefix(op: &str) -> bool { match op { "+" | "-" | "!" | "~" => true, _ => false, } } } macro_rules! parse_method { ($name:ident(&mut $self:ident) -> $type:ty $body:block) => { fn $name(&mut $self) -> $type { let next_token = $self.peek(); let record = ParseRecord { production_name: stringify!($name).to_string(), next_token: format!("{:?}", next_token), }; $self.parse_record.push(record); $body } }; } macro_rules! delimited { ($self:expr, $start:pat, $start_str:expr, $parse_fn:ident, $( $delim:pat )|+, $end:pat, $end_str:expr, nonstrict) => { delimited!($self, $start, $start_str, $parse_fn, $( $delim )|*, $end, $end_str, false) }; ($self:expr, $start:pat, $start_str:expr, $parse_fn:ident, $( $delim:pat )|+, $end:pat, $end_str:expr) => { delimited!($self, $start, $start_str, $parse_fn, $( $delim )|*, $end, $end_str, true) }; ($self:expr, $start:pat, $start_str:expr, $parse_fn:ident, $( $delim:pat )|+, $end:pat, $end_str:expr, $strictness:expr) => { { expect!($self, $start, $start_str); let mut acc = vec![]; loop { let peek = $self.peek(); match peek { $end | EOF => break, _ => (), } if !$strictness { match peek { $( $delim )|* => { $self.next(); continue }, _ => () } } acc.push($self.$parse_fn()?); match $self.peek() { $( $delim )|* => { $self.next(); continue }, _ => break }; } expect!($self, $end, $end_str); acc } }; } impl Parser { parse_method!(program(&mut self) -> ParseResult { let mut statements = Vec::new(); loop { match self.peek() { EOF => break, Newline | Semicolon => { self.next(); continue; }, _ => statements.push(self.statement()?), } } Ok(AST(statements)) }); parse_method!(statement(&mut self) -> ParseResult { //TODO handle error recovery here match self.peek() { Keyword(Type) => self.type_declaration().map(|decl| { Statement::Declaration(decl) }), Keyword(Func)=> self.func_declaration().map(|func| { Statement::Declaration(func) }), Keyword(Var) | Keyword(Const) => self.binding_declaration().map(|decl| Statement::Declaration(decl)), Keyword(Trait) => self.trait_declaration().map(|decl| Statement::Declaration(decl)), Keyword(Impl) => self.impl_declaration().map(|decl| Statement::Declaration(decl)), _ => self.expression().map(|expr| { Statement::ExpressionStatement(expr) } ), } }); parse_method!(type_declaration(&mut self) -> ParseResult { expect!(self, Keyword(Type), "'type'"); self.type_declaration_body() }); parse_method!(type_declaration_body(&mut self) -> ParseResult { if let Keyword(Alias) = self.peek() { self.type_alias() } else { let name = self.identifier()?; expect!(self, Operator(ref c) if **c == "=", "'='"); let body = self.type_body()?; Ok(Declaration::TypeDecl(name, body)) } }); parse_method!(type_alias(&mut self) -> ParseResult { expect!(self, Keyword(Alias), "'alias'"); let alias = self.identifier()?; expect!(self, Operator(ref c) if **c == "=", "'='"); let original = self.identifier()?; Ok(Declaration::TypeAlias(alias, original)) }); parse_method!(type_body(&mut self) -> ParseResult { let mut variants = Vec::new(); variants.push(self.variant_specifier()?); loop { if let Pipe = self.peek() { self.next(); variants.push(self.variant_specifier()?); } else { break; } } Ok(TypeBody(variants)) }); parse_method!(variant_specifier(&mut self) -> ParseResult { use self::Variant::*; let name = self.identifier()?; match self.peek() { LParen => { let tuple_members = delimited!(self, LParen, '(', type_name, Comma, RParen, ')'); Ok(TupleStruct(name, tuple_members)) }, LCurlyBrace => { let typed_identifier_list = delimited!(self, LCurlyBrace, '{', typed_identifier, Comma, RCurlyBrace, '}'); Ok(Record(name, typed_identifier_list)) }, _ => Ok(UnitStruct(name)) } }); parse_method!(typed_identifier(&mut self) -> ParseResult<(Rc, TypeName)> { let identifier = self.identifier()?; expect!(self, Colon, "':'"); let type_name = self.type_name()?; Ok((identifier, type_name)) }); parse_method!(func_declaration(&mut self) -> ParseResult { let signature = self.signature()?; if let LCurlyBrace = self.peek() { let statements = delimited!(self, LCurlyBrace, '{', statement, Newline | Semicolon, RCurlyBrace, '}'); Ok(Declaration::FuncDecl(signature, statements)) } else { Ok(Declaration::FuncSig(signature)) } }); parse_method!(signature(&mut self) -> ParseResult { expect!(self, Keyword(Func), "'fn'"); let name = self.identifier()?; let params = delimited!(self, LParen, '(', formal_param, Comma, RParen, ')'); let type_anno = match self.peek() { Colon => Some(self.type_anno()?), _ => None, }; Ok(Signature { name, params, type_anno }) }); parse_method!(formal_param(&mut self) -> ParseResult { let name = self.identifier()?; let ty = match self.peek() { Colon => Some(self.type_anno()?), _ => None }; Ok((name, ty)) }); parse_method!(binding_declaration(&mut self) -> ParseResult { let constant = match self.next() { Keyword(Var) => false, Keyword(Const) => true, _ => return ParseError::new("Expected 'var' or 'const'"), }; let name = self.identifier()?; expect!(self, Operator(ref o) if **o == "=", "'='"); let expr = self.expression()?; Ok(Declaration::Binding { name, constant, expr }) }); parse_method!(trait_declaration(&mut self) -> ParseResult { unimplemented!() }); parse_method!(impl_declaration(&mut self) -> ParseResult { expect!(self, Keyword(Impl), "'impl'"); let first = self.type_name()?; let second = if let Keyword(For) = self.peek() { self.next(); Some(self.type_name()?) } else { None }; let block = self.decl_block()?; let result = match (first, second) { (first, Some(second)) => { match first { TypeName::Singleton { ref name, ref params } if params.len() == 0 => Declaration::Impl { type_name: second, trait_name: Some(name.clone()), block }, _ => return ParseError::new(&format!("Invalid name for a trait")), } }, (first, None) => Declaration::Impl { type_name: first, trait_name: None, block } }; Ok(result) }); parse_method!(decl_block(&mut self) -> ParseResult> { Ok(delimited!(self, LCurlyBrace, '{', func_declaration, Newline | Semicolon, RCurlyBrace, '}', nonstrict)) }); parse_method!(expression(&mut self) -> ParseResult { let mut expr_body = self.precedence_expr(Operation::min_precedence())?; let type_anno = match self.peek() { Colon => Some(self.type_anno()?), _ => None }; if let Some(_) = expr_body.1 { return ParseError::new("Bad parse state"); } expr_body.1 = type_anno; Ok(expr_body) }); parse_method!(type_anno(&mut self) -> ParseResult { expect!(self, Colon, "':'"); self.type_name() }); parse_method!(type_name(&mut self) -> ParseResult { use self::TypeName::*; Ok(match self.peek() { LParen => Tuple(delimited!(self, LParen, '(', type_name, Comma, RParen, ')')), _ => Singleton { name: self.identifier()?, params: match self.peek() { LAngleBracket => delimited!(self, LAngleBracket, '<', type_name, Comma, RAngleBracket, '>'), _ => vec![], } } }) }); // this implements Pratt parsing, see http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-expression-parsing-made-easy/ fn precedence_expr(&mut self, precedence: i32) -> ParseResult { let next_token = self.peek(); let record = ParseRecord { production_name: "precedence_expr".to_string(), next_token: format!("{:?}", next_token), }; self.parse_record.push(record); let mut lhs = self.prefix_expr()?; loop { let new_precedence = match self.peek() { Operator(op) => Operation::get_precedence(&*op), Period => Operation::get_precedence("."), _ => break, }; if precedence >= new_precedence { break; } let op_str = match self.next() { Operator(op) => op, Period => Rc::new(".".to_string()), _ => unreachable!(), }; let rhs = self.precedence_expr(new_precedence)?; let operation = Operation(op_str); lhs = Expression(ExpressionType::BinExp(operation, Box::new(lhs), Box::new(rhs)), None); } Ok(lhs) } parse_method!(prefix_expr(&mut self) -> ParseResult { match self.peek() { Operator(ref op) if Operation::is_prefix(&*op) => { let op_str = match self.next() { Operator(op) => op, _ => unreachable!(), }; let expr = self.primary()?; Ok(Expression( ExpressionType::PrefixExp(Operation(op_str), Box::new(expr)), None)) }, _ => self.primary() } }); parse_method!(primary(&mut self) -> ParseResult { match self.peek() { LParen => self.paren_expr(), Keyword(Kw::If) => self.if_expr(), Keyword(Kw::Match) => self.match_expr(), Keyword(Kw::For) => self.for_expr(), Identifier(_) => self.identifier_expr(), _ => self.literal(), } }); parse_method!(paren_expr(&mut self) -> ParseResult { use self::ExpressionType::*; let mut inner = delimited!(self, LParen, '(', expression, Comma, RParen, ')'); match inner.len() { 0 => Ok(Expression(TupleLiteral(vec![]), None)), 1 => Ok(inner.pop().unwrap()), _ => Ok(Expression(TupleLiteral(inner), None)), } }); parse_method!(identifier_expr(&mut self) -> ParseResult { use self::ExpressionType::*; let identifier = self.identifier()?; match self.peek() { LParen => { let call_params = self.call_expr()?; Ok(Expression(Call { name: identifier, params: call_params, }, None)) }, LSquareBracket => { let indexers = self.index_expr()?; Ok(Expression(Index { indexee: Box::new(Expression(Variable(identifier), None)), indexers: indexers, }, None)) } _ => Ok(Expression(Variable(identifier), None)) } }); parse_method!(call_expr(&mut self) -> ParseResult> { Ok(delimited!(self, LParen, ')', expression, Comma, RParen, '(')) }); parse_method!(index_expr(&mut self) -> ParseResult> { Ok(delimited!(self, LSquareBracket, '[', expression, Comma, RSquareBracket, ']')) }); parse_method!(if_expr(&mut self) -> ParseResult { expect!(self, Keyword(Kw::If), "'if'"); let condition = self.expression()?; let then_clause = self.block()?; let else_clause = self.else_clause()?; Ok(Expression(ExpressionType::IfExpression(Box::new(condition), then_clause, else_clause), None)) }); parse_method!(else_clause(&mut self) -> ParseResult>> { Ok(if let Keyword(Kw::Else) = self.peek() { self.next(); Some(self.block()?) } else { None }) }); parse_method!(block(&mut self) -> ParseResult> { Ok(delimited!(self, LCurlyBrace, '{', statement, Newline | Semicolon, RCurlyBrace, '}', nonstrict)) }); parse_method!(match_expr(&mut self) -> ParseResult { expect!(self, Keyword(Kw::Match), "'match'"); let expr = self.expression()?; //TODO abstract these errors into the delimited macro //expect!(self, LCurlyBrace, "Expected '{'"); let body = self.match_body()?; //expect!(self, RCurlyBrace, "Expected '}'"); Ok(Expression(ExpressionType::MatchExpression(Box::new(expr), body), None)) }); parse_method!(match_body(&mut self) -> ParseResult> { Ok(delimited!(self, LCurlyBrace, '{', match_arm, Comma, RCurlyBrace, '}')) }); parse_method!(match_arm(&mut self) -> ParseResult { let pat = self.pattern()?; expect!(self, Operator(ref c) if **c == "=>", "'=>'"); let expr = self.expression()?; Ok(MatchArm { pat, expr }) }); parse_method!(pattern(&mut self) -> ParseResult { let identifier = self.identifier()?; Ok(Pattern(identifier)) }); parse_method!(for_expr(&mut self) -> ParseResult { expect!(self, Keyword(Kw::For), "'for'"); Ok(Expression(ExpressionType::ForExpression, None)) }); parse_method!(identifier(&mut self) -> ParseResult> { match self.next() { Identifier(s) => Ok(s), p => ParseError::new(&format!("Expected an identifier, got {:?}", p)), } }); parse_method!(literal(&mut self) -> ParseResult { use self::ExpressionType::*; match self.peek() { DigitGroup(_) | HexNumberSigil | BinNumberSigil | Period => self.number_literal(), Keyword(Kw::True) => { self.next(); Ok(Expression(BoolLiteral(true), None)) }, Keyword(Kw::False) => { self.next(); Ok(Expression(BoolLiteral(false), None)) }, StrLiteral(s) => { self.next(); Ok(Expression(StringLiteral(s), None)) } e => ParseError::new(&format!("Expected a literal expression, got {:?}", e)), } }); parse_method!(number_literal(&mut self) -> ParseResult { match self.peek() { HexNumberSigil | BinNumberSigil => self.int_literal(), _ => self.float_literal(), } }); parse_method!(int_literal(&mut self) -> ParseResult { use self::ExpressionType::*; match self.next() { BinNumberSigil => { let digits = self.digits()?; let n = parse_binary(digits)?; Ok(Expression(IntLiteral(n), None)) }, HexNumberSigil => { ParseError::new("Not implemented") }, _ => return ParseError::new("Expected '0x' or '0b'"), } }); parse_method!(float_literal(&mut self) -> ParseResult { use self::ExpressionType::*; let mut digits = self.digits()?; if let TokenType::Period = self.peek() { self.next(); digits.push_str("."); digits.push_str(&self.digits()?); match digits.parse::() { Ok(f) => Ok(Expression(FloatLiteral(f), None)), Err(e) => ParseError::new(&format!("Float failed to parse with error: {}", e)), } } else { match digits.parse::() { Ok(d) => Ok(Expression(IntLiteral(d), None)), Err(e) => ParseError::new(&format!("Integer failed to parse with error: {}", e)), } } }); parse_method!(digits(&mut self) -> ParseResult { let mut ds = String::new(); loop { match self.peek() { Underscore => { self.next(); continue; }, DigitGroup(ref s) => { self.next(); ds.push_str(s)}, _ => break, } } Ok(ds) }); } fn parse_binary(digits: String) -> ParseResult { let mut result: u64 = 0; let mut multiplier = 1; for d in digits.chars().rev() { match d { '1' => result += multiplier, '0' => (), _ => return ParseError::new("Encountered a character not '1' or '0 while parsing a binary literal"), } multiplier *= 2; } Ok(result) } pub fn parse(input: Vec) -> (Result, Vec) { let mut parser = Parser::new(input); let ast = parser.program(); let trace = parser.parse_record.into_iter().map(|r| { format!("Production `{}`, token: {:?}", r.production_name, r.next_token) }).collect(); (ast, trace) } #[cfg(test)] mod parse_tests { use ::std::rc::Rc; use super::{AST, Expression, Statement, Operation, TypeBody, Variant, parse, tokenize}; use super::Statement::*; use super::Declaration::*; use super::Signature; use super::TypeName::*; use super::ExpressionType::*; use super::Variant::*; macro_rules! rc { ($string:tt) => { Rc::new(stringify!($string).to_string()) } } macro_rules! parse_test { ($string:expr, $correct:expr) => { assert_eq!(parse(tokenize($string)).0.unwrap(), $correct) } } macro_rules! parse_error { ($string:expr) => { assert!(parse(tokenize($string)).0.is_err()) } } macro_rules! binexp { ($op:expr, $lhs:expr, $rhs:expr) => { BinExp(op!($op), Box::new(Expression($lhs, None)), Box::new(Expression($rhs, None))) } } macro_rules! prefexp { ($op:expr, $lhs:expr) => { PrefixExp(op!($op), Box::new(Expression($lhs, None))) } } macro_rules! op { ($op:expr) => { Operation(Rc::new($op.to_string())) } } macro_rules! var { ($var:expr) => { Variable(Rc::new($var.to_string())) } } macro_rules! exprstatement { ($expr_type:expr) => { Statement::ExpressionStatement(Expression($expr_type, None)) }; ($expr_type:expr, $type_anno:expr) => { Statement::ExpressionStatement(Expression($expr_type, Some($type_anno))) }; } macro_rules! ex { ($expr_type:expr) => { Expression($expr_type, None) } } macro_rules! ty { ($name:expr) => { Singleton { name: Rc::new($name.to_string()), params: vec![] } }; } #[test] fn parsing_number_literals_and_binexps() { parse_test!(".2", AST(vec![exprstatement!(FloatLiteral(0.2))])); parse_test!("8.1", AST(vec![exprstatement!(FloatLiteral(8.1))])); parse_test!("0b010", AST(vec![exprstatement!(IntLiteral(2))])); parse_test!("3; 4; 4.3", AST( vec![exprstatement!(IntLiteral(3)), exprstatement!(IntLiteral(4)), exprstatement!(FloatLiteral(4.3))])); parse_test!("1 + 2 * 3", AST(vec! [ exprstatement!(binexp!("+", IntLiteral(1), binexp!("*", IntLiteral(2), IntLiteral(3)))) ])); parse_test!("1 * 2 + 3", AST(vec! [ exprstatement!(binexp!("+", binexp!("*", IntLiteral(1), IntLiteral(2)), IntLiteral(3))) ])); parse_test!("1 && 2", AST(vec![exprstatement!(binexp!("&&", IntLiteral(1), IntLiteral(2)))])); parse_test!("1 + 2 * 3 + 4", AST(vec![exprstatement!( binexp!("+", binexp!("+", IntLiteral(1), binexp!("*", IntLiteral(2), IntLiteral(3))), IntLiteral(4)))])); parse_test!("(1 + 2) * 3", AST(vec! [exprstatement!(binexp!("*", binexp!("+", IntLiteral(1), IntLiteral(2)), IntLiteral(3)))])); parse_test!(".1 + .2", AST(vec![exprstatement!(binexp!("+", FloatLiteral(0.1), FloatLiteral(0.2)))])); } #[test] fn parsing_tuples() { parse_test!("()", AST(vec![exprstatement!(TupleLiteral(vec![]))])); parse_test!("(\"hella\", 34)", AST(vec![exprstatement!( TupleLiteral( vec![ex!(StringLiteral(rc!(hella))), ex!(IntLiteral(34))] ) )])); parse_test!("((1+2), \"slough\")", AST(vec![exprstatement!(TupleLiteral(vec![ ex!(binexp!("+", IntLiteral(1), IntLiteral(2))), ex!(StringLiteral(rc!(slough))), ]))])) } #[test] fn parsing_identifiers() { parse_test!("a", AST(vec![exprstatement!(var!("a"))])); parse_test!("a + b", AST(vec![exprstatement!(binexp!("+", var!("a"), var!("b")))])); //parse_test!("a[b]", AST(vec![Expression( //parse_test!("a[]", <- TODO THIS NEEDS TO FAIL //parse_test!(damn()[a] ,<- TODO needs to succeed parse_test!("a[b,c]", AST(vec![exprstatement!(Index { indexee: Box::new(ex!(var!("a"))), indexers: vec![ex!(var!("b")), ex!(var!("c"))]} )])); } #[test] fn parsing_complicated_operators() { parse_test!("a <- b", AST(vec![exprstatement!(binexp!("<-", var!("a"), var!("b")))])); parse_test!("a || b", AST(vec![exprstatement!(binexp!("||", var!("a"), var!("b")))])); parse_test!("a<>b", AST(vec![exprstatement!(binexp!("<>", var!("a"), var!("b")))])); parse_test!("a.b.c.d", AST(vec![exprstatement!(binexp!(".", binexp!(".", binexp!(".", var!("a"), var!("b")), var!("c")), var!("d")))])); parse_test!("-3", AST(vec![exprstatement!(prefexp!("-", IntLiteral(3)))])); parse_test!("-0.2", AST(vec![exprstatement!(prefexp!("-", FloatLiteral(0.2)))])); parse_test!("!3", AST(vec![exprstatement!(prefexp!("!", IntLiteral(3)))])); parse_test!("a <- -b", AST(vec![exprstatement!(binexp!("<-", var!("a"), prefexp!("-", var!("b"))))])); parse_test!("a <--b", AST(vec![exprstatement!(binexp!("<--", var!("a"), var!("b")))])); } #[test] fn parsing_functions() { parse_test!("fn oi()", AST(vec![Declaration(FuncSig(Signature { name: rc!(oi), params: vec![], type_anno: None }))])); parse_test!("oi()", AST(vec![exprstatement!(Call { name: rc!(oi), params: vec![] })])); parse_test!("oi(a, 2 + 2)", AST(vec![exprstatement!(Call { name: rc!(oi), params: vec![ex!(var!("a")), ex!(binexp!("+", IntLiteral(2), IntLiteral(2)))] })])); parse_error!("a(b,,c)"); parse_test!("fn a(b, c: Int): Int", AST(vec![Declaration( FuncSig(Signature { name: rc!(a), params: vec![ (rc!(b), None), (rc!(c), Some(ty!("Int"))) ], type_anno: Some(ty!("Int")) }))])); parse_test!("fn a(x) { x() }", AST(vec![Declaration( FuncDecl(Signature { name: rc!(a), params: vec![(rc!(x),None)], type_anno: None }, vec![exprstatement!(Call { name: rc!(x), params: vec![] })]))])); } #[test] fn parsing_bools() { parse_test!("false", AST(vec![exprstatement!(BoolLiteral(false))])); parse_test!("true", AST(vec![exprstatement!(BoolLiteral(true))])); } #[test] fn parsing_strings() { parse_test!(r#""hello""#, AST(vec![exprstatement!(StringLiteral(rc!(hello)))])); } #[test] fn parsing_types() { parse_test!("type Yolo = Yolo", AST(vec![Declaration(TypeDecl(rc!(Yolo), TypeBody(vec![UnitStruct(rc!(Yolo))])))])); parse_test!("type alias Sex = Drugs", AST(vec![Declaration(TypeAlias(rc!(Sex), rc!(Drugs)))])); parse_test!("type Sanchez = Miguel | Alejandro(Int, Option) | Esparanza { a: Int, b: String }", AST(vec![Declaration(TypeDecl(rc!(Sanchez), TypeBody(vec![ UnitStruct(rc!(Miguel)), TupleStruct(rc!(Alejandro), vec![ Singleton { name: rc!(Int), params: vec![] }, Singleton { name: rc!(Option), params: vec![Singleton { name: rc!(a), params: vec![] }] }, ]), Record(rc!(Esparanza), vec![ (rc!(a), Singleton { name: rc!(Int), params: vec![] }), (rc!(b), Singleton { name: rc!(String), params: vec![] }), ])])))])); } #[test] fn parsing_bindings() { parse_test!("var a = 10", AST(vec![Declaration(Binding { name: rc!(a), constant: false, expr: ex!(IntLiteral(10)) } )])); parse_test!("const a = 2 + 2", AST(vec![Declaration(Binding { name: rc!(a), constant: true, expr: ex!(binexp!("+", IntLiteral(2), IntLiteral(2))) }) ])); } #[test] fn parsing_block_expressions() { parse_test!("if a() { b(); c() }", AST(vec![exprstatement!( IfExpression(Box::new(ex!(Call { name: rc!(a), params: vec![]})), vec![exprstatement!(Call { name: rc!(b), params: vec![]}), exprstatement!(Call { name: rc!(c), params: vec![] })], None) )])); parse_test!(r#" if true { const a = 10 b } else { c }"#, AST(vec![exprstatement!(IfExpression(Box::new(ex!(BoolLiteral(true))), vec![Declaration(Binding { name: rc!(a), constant: true, expr: ex!(IntLiteral(10)) }), exprstatement!(Variable(rc!(b)))], Some(vec![exprstatement!(Variable(rc!(c)))])))]) ); } #[test] fn parsing_impls() { parse_test!("impl Heh { fn yolo(); fn swagg(); }", AST(vec![ Declaration(Impl { type_name: ty!("Heh"), trait_name: None, block: vec![ FuncSig(Signature { name: rc!(yolo), params: vec![], type_anno: None }), FuncSig(Signature { name: rc!(swagg), params: vec![], type_anno: None }) ] })])); parse_test!("impl Mondai for Lollerino { fn yolo(); fn swagg(); }", AST(vec![ Declaration(Impl { type_name: ty!("Lollerino"), trait_name: Some(rc!(Mondai)), block: vec![ FuncSig(Signature { name: rc!(yolo), params: vec![], type_anno: None}), FuncSig(Signature { name: rc!(swagg), params: vec![], type_anno: None }) ] })])); parse_test!("impl Option { fn oi() }", AST(vec![ Declaration(Impl { type_name: Singleton { name: rc!(Option), params: vec![ty!("WTFMate")]}, trait_name: None, block: vec![ FuncSig(Signature { name: rc!(oi), params: vec![], type_anno: None }), ] })])); } #[test] fn parsing_type_annotations() { parse_test!("const a = b : Int", AST(vec![ Declaration(Binding { name: rc!(a), constant: true, expr: Expression(var!("b"), Some(ty!("Int"))) })])); parse_test!("a : Int", AST(vec![ exprstatement!(var!("a"), ty!("Int")) ])); parse_test!("a : Option", AST(vec![ exprstatement!(var!("a"), Singleton { name: rc!(Option), params: vec![ty!("Int")] }) ])); parse_test!("a : KoreanBBQSpecifier >", AST(vec![ exprstatement!(var!("a"), Singleton { name: rc!(KoreanBBQSpecifier), params: vec![ ty!("Kimchi"), Singleton { name: rc!(Option), params: vec![ty!("Bulgogi")] } ] }) ])); parse_test!("a : (Int, Yolo)", AST(vec![ exprstatement!(var!("a"), Tuple( vec![ty!("Int"), Singleton { name: rc!(Yolo), params: vec![ty!("a")] }]))])); } }