added missing files
This commit is contained in:
Productive2
parent
1daae9c30a
commit
ccc78148d8
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from .lexer import Lexer
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from .parser import Parser
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from .interpreter import Interpreter
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from .meta.exceptions import ParseError
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from .meta.tokentype import TokenType
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from .meta.tokenobject import Token
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from typing import List, Union
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from .meta.expression import Variable, Assignment, Logical, Call, Binary, Unary, Literal, Grouping, Expression, Get, Set, This, Super
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from .meta.statement import StatementExpr, Var, Del, Block, If, While, Break, Function, Return, Class
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class Parser(object):
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"""A simple recursive-descent top-down parser"""
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def __init__(self, tokens: List[Token]):
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"""Object constructor"""
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self.tokens = tokens
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self.current: int = 0
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def check(self, token_type):
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"""
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Helper method for self.match
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"""
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if self.done():
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return False
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elif self.peek().kind == token_type:
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return True
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return False
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def throw(self, token: Token, message: str) -> ParseError:
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"""Returns ParseError with the given message"""
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return ParseError(token, message)
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def synchronize(self):
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"""Synchronizes the parser's state to recover after
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an error occurred while parsing"""
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self.step()
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while not self.done():
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if self.previous().kind == TokenType.SEMICOLON:
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break
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else:
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token_type = self.peek().kind
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if token_type in (
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TokenType.IF, TokenType.CLASS, TokenType.VAR, TokenType.FOR, TokenType.WHILE,
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TokenType.RETURN, TokenType.FUN
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):
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return
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self.step()
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def peek(self):
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"""
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Returns a token without consuming it
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"""
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return self.tokens[self.current]
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def previous(self):
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"""
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Returns the most recently consumed token
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"""
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return self.tokens[self.current - 1]
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def done(self):
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"""
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Returns True if we reached EOF
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"""
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return self.peek().kind == TokenType.EOF
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def match(self, *types: Union[TokenType, List[TokenType]]):
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"""
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Checks if the current token matches
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any of the given token type(s)
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"""
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for token_type in types:
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if self.check(token_type):
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self.step()
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return True
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return False
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def consume(self, token_type, message: str):
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"""
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Consumes a token, raises an error
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with the given message if the current token
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differs from the expected one
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"""
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if self.check(token_type):
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return self.step()
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raise self.throw(self.peek(), message)
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def primary(self):
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"""Parses unary expressions (literals)"""
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if self.match(TokenType.FALSE):
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return Literal(False)
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elif self.match(TokenType.TRUE):
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return Literal(True)
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elif self.match(TokenType.NIL):
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return Literal(None)
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elif self.match(TokenType.NUM, TokenType.STR):
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return Literal(self.previous().literal)
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elif self.match(TokenType.LP):
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expr: Expression = self.expression()
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self.consume(TokenType.RP, "Unexpected error while parsing parenthesized expression")
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return Grouping(expr)
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elif self.match(TokenType.ID):
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return Variable(self.previous())
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elif self.match(TokenType.SUPER):
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keyword = self.previous()
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self.consume(TokenType.DOT, "Expecting '.' after 'super'")
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method = self.consume(TokenType.ID, "Expecting superclass method name")
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return Super(keyword, method)
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elif self.match(TokenType.THIS):
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return This(self.previous())
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raise self.throw(self.peek(), "Invalid syntax")
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def finish_call(self, callee):
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"""Parses a function call"""
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arguments = []
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if not self.check(TokenType.RP):
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while True:
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if len(arguments) >= 255:
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raise self.throw(self.peek(), "Cannot have more than 255 arguments")
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arguments.append(self.expression())
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if not self.match(TokenType.COMMA):
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break
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paren = self.consume(TokenType.RP, "Unexpected error while parsing call")
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return Call(callee, paren, arguments)
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def call(self):
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"""Parses call expressions"""
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expr = self.primary()
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while True:
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if self.match(TokenType.LP):
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expr = self.finish_call(expr)
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elif self.match(TokenType.DOT):
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name = self.consume(TokenType.ID, "Expecting property after '.'")
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expr = Get(expr, name)
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else:
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break
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return expr
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def unary(self):
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"""Parses unary expressions"""
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if self.match(TokenType.NEG, TokenType.MINUS):
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operator: Token = self.previous()
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right: Expression = self.unary()
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return Unary(operator, right)
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return self.call()
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def pow(self):
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"""Parses pow expressions"""
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expr: Expression = self.unary()
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while self.match(TokenType.POW):
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operator: Token = self.previous()
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right: Expression = self.unary()
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expr = Binary(expr, operator, right)
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return expr
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def multiplication(self):
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"""
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Parses multiplications and divisions
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"""
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expr: Expression = self.pow()
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while self.match(TokenType.STAR, TokenType.SLASH, TokenType.MOD):
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operator: Token = self.previous()
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right: Expression = self.pow()
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expr = Binary(expr, operator, right)
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return expr
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def addition(self):
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"""
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Parses additions and subtractions
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"""
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expr: Expression = self.multiplication()
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while self.match(TokenType.PLUS, TokenType.MINUS):
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operator: Token = self.previous()
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right: Expression = self.multiplication()
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expr = Binary(expr, operator, right)
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return expr
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def comparison(self):
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"""
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Parses comparison expressions
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"""
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expr: Expression = self.addition()
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while self.match(TokenType.GT, TokenType.GE, TokenType.LT, TokenType.LE, TokenType.NE):
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operator: Token = self.previous()
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right: Expression = self.addition()
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expr = Binary(expr, operator, right)
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return expr
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def equality(self):
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"""
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Parses equality expressions
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"""
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expr: Expression = self.comparison()
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while self.match(TokenType.NEG, TokenType.DEQ):
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operator: Token = self.previous()
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right: Expression = self.comparison()
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expr = Binary(expr, operator, right)
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return expr
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def logical_and(self):
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"""Parses a logical and expression"""
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expr = self.equality()
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while self.match(TokenType.AND):
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operator = self.previous()
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right = self.equality()
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expr = Logical(expr, operator, right)
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return expr
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def logical_or(self):
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"""Parses a logical or expression"""
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expr = self.logical_and()
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while self.match(TokenType.OR):
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operator = self.previous()
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right = self.logical_and()
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expr = Logical(expr, operator, right)
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return expr
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def assignment(self):
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"""
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Parses an assignment expression
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"""
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expr = self.logical_or()
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if self.match(TokenType.EQ):
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eq = self.previous()
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value = self.assignment()
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if isinstance(expr, Variable):
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name = expr.name
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return Assignment(name, value)
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elif isinstance(expr, Get):
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return Set(expr.object, expr.name, value)
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raise self.throw(eq, "Invalid syntax")
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return expr
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def expression(self):
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"""
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Parses an expression
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"""
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return self.assignment()
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def step(self):
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"""Steps 1 token forward"""
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if not self.done():
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self.current += 1
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return self.previous()
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def del_statement(self):
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"""Returns a del AST node"""
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value = self.expression()
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self.consume(TokenType.SEMICOLON, "Missing semicolon after statement")
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return Del(value)
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def expression_statement(self):
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"""Returns a StatemenrExpr AST node"""
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value = self.expression()
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self.consume(TokenType.SEMICOLON, "Missing semicolon after statement")
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return StatementExpr(value)
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def block(self):
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"""Returns a new environment to enable block scoping"""
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statements = []
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while not self.check(TokenType.RB) and not self.done():
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statements.append(self.declaration())
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self.consume(TokenType.RB, "Unexpected end of block")
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return statements
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def if_statement(self):
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"""Parses an IF statement"""
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self.consume(TokenType.LP, "The if condition must be parenthesized")
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cond = self.expression()
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self.consume(TokenType.RP, "The if condition must be parenthesized")
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then_branch = self.statement()
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else_branch = None
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if self.match(TokenType.ELSE):
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else_branch = self.statement()
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return If(cond, then_branch, else_branch)
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def while_statement(self):
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"""Parses a while statement"""
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self.consume(TokenType.LP, "The while condition must be parenthesized")
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cond = self.expression()
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self.consume(TokenType.RP, "The while condition must be parenthesized")
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body = self.statement()
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return While(cond, body)
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def for_statement(self):
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"""Parses a for statement"""
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self.consume(TokenType.LP, "The for condition must be parenthesized")
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if self.match(TokenType.SEMICOLON):
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init = None
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elif self.match(TokenType.VAR):
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init = self.var_declaration()
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else:
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init = self.expression_statement()
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condition = None
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if not self.check(TokenType.SEMICOLON):
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condition = self.expression()
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self.consume(TokenType.SEMICOLON, "Missing semicolon after loop condition")
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incr = None
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if not self.check(TokenType.RP):
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incr = self.expression()
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self.consume(TokenType.RP, "The for condition must be parenthesized")
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body = self.statement()
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if incr:
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body = Block([body, StatementExpr(incr)])
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if not condition:
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condition = Literal(True)
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body = While(condition, body)
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if init:
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body = Block([init, body])
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return body
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def break_statement(self):
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"""Parses a break statement"""
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if self.check(TokenType.SEMICOLON):
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return self.step()
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raise ParseError(self.peek(), "Invalid syntax")
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def return_statement(self):
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"""Parses a return statement"""
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keyword = self.previous()
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value = None
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if not self.check(TokenType.SEMICOLON):
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value = self.expression()
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self.consume(TokenType.SEMICOLON, "Missing semicolon after statement")
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return Return(keyword, value)
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def statement(self):
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"""Parses a statement"""
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if self.match(TokenType.IF):
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return self.if_statement()
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elif self.match(TokenType.RETURN):
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return self.return_statement()
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elif self.match(TokenType.FOR):
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return self.for_statement()
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elif self.match(TokenType.WHILE):
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return self.while_statement()
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elif self.match(TokenType.BREAK):
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return Break(self.break_statement())
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elif self.match(TokenType.LB):
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return Block(self.block())
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elif self.match(TokenType.DEL):
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return self.del_statement()
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return self.expression_statement()
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def var_declaration(self):
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"""Parses a var declaration"""
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name = self.consume(TokenType.ID, "Expecting a variable name")
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init = None
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if self.match(TokenType.EQ):
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init = self.expression()
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self.consume(TokenType.SEMICOLON, "Missing semicolon after declaration")
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return Var(name, init)
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def function(self, kind: str):
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"""Parses a function declaration"""
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name = self.consume(TokenType.ID, f"Expecting {kind} name")
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self.consume(TokenType.LP, f"Expecting parenthesis after {kind} name")
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parameters = []
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if not self.check(TokenType.RP):
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while True:
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if len(parameters) >= 255:
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raise self.throw(self.peek(), "Cannot have more than 255 arguments")
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parameter = self.consume(TokenType.ID, "Expecting parameter name")
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if parameter in parameters:
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raise self.throw(self.peek(), "Multiple parameters with the same name in function declaration are not allowed")
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parameters.append(parameter)
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if not self.match(TokenType.COMMA):
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break
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self.consume(TokenType.RP, "Unexpected error while parsing function declaration")
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self.consume(TokenType.LB, f"Expecting '{{' before {kind} body")
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body = self.block()
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return Function(name, parameters, body)
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def class_declaration(self):
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"""Parses a class declaration"""
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name = self.consume(TokenType.ID, "Expecting class name")
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superclass = None
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if self.match(TokenType.LT):
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self.consume(TokenType.ID, "Expecting superclass name")
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superclass = Variable(self.previous())
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self.consume(TokenType.LB, "Expecting '{' before class body")
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methods = []
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while not self.check(TokenType.RB) and not self.done():
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methods.append(self.function("method"))
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self.consume(TokenType.RB, "Expecting '}' after class body")
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return Class(name, methods, superclass)
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def declaration(self):
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"""Parses a declaration"""
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try:
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if self.match(TokenType.CLASS):
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return self.class_declaration()
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elif self.match(TokenType.FUN):
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return self.function("function")
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elif self.match(TokenType.VAR):
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return self.var_declaration()
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return self.statement()
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except ParseError:
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self.synchronize()
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raise
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def parse(self):
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"""
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Starts to parse
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"""
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statements = []
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while not self.done():
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statements.append(self.declaration())
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return statements
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@ -0,0 +1,281 @@
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from .meta.exceptions import JAPLError
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from .meta.expression import Expression
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from .meta.statement import Statement
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from .meta.functiontype import FunctionType
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from .meta.classtype import ClassType
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from .meta.looptype import LoopType
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try:
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from functools import singledispatchmethod
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except ImportError:
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from singledispatchmethod import singledispatchmethod # Backport
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from typing import List, Union
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from collections import deque
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class Resolver(Expression.Visitor, Statement.Visitor):
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"""
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This class serves the purpose of correctly resolving
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name bindings (even with closures) efficiently
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"""
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def __init__(self, interpreter):
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"""
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Object constructor
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"""
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self.interpreter = interpreter
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self.scopes = deque()
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self.current_function = FunctionType.NONE
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self.current_loop = LoopType.NONE
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self.current_class = ClassType.NONE
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@singledispatchmethod
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def resolve(self, stmt_or_expr: Union[Statement, Expression, List[Statement]]):
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"""Generic method to dispatch statements/expressions"""
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raise NotImplementedError
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def begin_scope(self):
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"""
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Opens a new scope
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"""
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self.scopes.append({})
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def end_scope(self):
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"""
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Ends a scope
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"""
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self.scopes.pop()
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@resolve.register
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def resolve_statement(self, stmt: Statement):
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"""
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Resolves names for the given group
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of statements
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"""
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stmt.accept(self)
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@resolve.register
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def resolve_expression(self, expression: Expression):
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"""
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Resolves an expression
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"""
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return expression.accept(self)
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@resolve.register
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def resolve_statements(self, stmt: list):
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"""Resolves multiple statements"""
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for statement in stmt:
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self.resolve(statement)
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def declare(self, name):
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"""
|
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Declares a new variable
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"""
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if not self.scopes:
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return
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scope = self.scopes[-1]
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if name.lexeme in scope:
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raise JAPLError(name, "Cannot re-declare the same variable in local scope, use assignment instead")
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||||
scope[name.lexeme] = False
|
||||
|
||||
def define(self, name):
|
||||
"""
|
||||
Defines a new variable
|
||||
"""
|
||||
|
||||
if not self.scopes:
|
||||
return
|
||||
scope = self.scopes[-1]
|
||||
scope[name.lexeme] = True
|
||||
|
||||
def visit_block(self, block):
|
||||
"""Starts name resolution on a given block"""
|
||||
|
||||
self.begin_scope()
|
||||
self.resolve(block.statements)
|
||||
self.end_scope()
|
||||
|
||||
def visit_var_stmt(self, stmt):
|
||||
"""Visits a var statement node"""
|
||||
|
||||
self.declare(stmt.name)
|
||||
if stmt.init:
|
||||
self.resolve(stmt.init)
|
||||
self.define(stmt.name)
|
||||
|
||||
def visit_var_expr(self, expr):
|
||||
"""Visits a var expression node"""
|
||||
|
||||
if self.scopes and self.scopes[-1].get(expr.name.lexeme) is False:
|
||||
raise JAPLError(expr.name, f"Cannot read local variable in its own initializer")
|
||||
self.resolve_local(expr, expr.name)
|
||||
|
||||
def resolve_local(self, expr, name):
|
||||
"""Resolves local variables"""
|
||||
|
||||
i = 0
|
||||
for scope in reversed(self.scopes):
|
||||
if name.lexeme in scope:
|
||||
self.interpreter.resolve(expr, i)
|
||||
i += 1
|
||||
|
||||
def resolve_function(self, function, function_type: FunctionType):
|
||||
"""Resolves function objects"""
|
||||
|
||||
enclosing = self.current_function
|
||||
self.current_function = function_type
|
||||
self.begin_scope()
|
||||
for param in function.params:
|
||||
self.declare(param)
|
||||
self.define(param)
|
||||
self.resolve(function.body)
|
||||
self.end_scope()
|
||||
self.current_function = enclosing
|
||||
|
||||
def visit_assign(self, expr):
|
||||
"""Visits an assignment expression"""
|
||||
|
||||
self.resolve(expr.value)
|
||||
self.resolve_local(expr, expr.name)
|
||||
|
||||
def visit_function(self, stmt):
|
||||
"""Visits a function statement"""
|
||||
|
||||
self.declare(stmt.name)
|
||||
self.define(stmt.name)
|
||||
self.resolve_function(stmt, FunctionType.FUNCTION)
|
||||
|
||||
def visit_class(self, stmt):
|
||||
"""Visits a class statement"""
|
||||
|
||||
enclosing = self.current_class
|
||||
self.current_class = ClassType.CLASS
|
||||
self.declare(stmt.name)
|
||||
self.define(stmt.name)
|
||||
if stmt.superclass:
|
||||
if stmt.superclass.name.lexeme == stmt.name.lexeme:
|
||||
raise JAPLError(stmt.name, "A class cannot inherit from itself")
|
||||
self.resolve(stmt.superclass)
|
||||
self.begin_scope()
|
||||
self.scopes[-1]["super"] = True
|
||||
self.begin_scope()
|
||||
self.scopes[-1]["this"] = True
|
||||
for method in stmt.methods:
|
||||
ftype = FunctionType.METHOD
|
||||
if method.name.lexeme == "init":
|
||||
ftype = FunctionType.INIT
|
||||
self.resolve_function(method, ftype)
|
||||
self.end_scope()
|
||||
if stmt.superclass:
|
||||
self.end_scope()
|
||||
self.current_class = enclosing
|
||||
|
||||
def visit_statement_expr(self, stmt):
|
||||
"""Visits a statement expression node"""
|
||||
|
||||
self.resolve(stmt.expression)
|
||||
|
||||
def visit_if(self, stmt):
|
||||
"""Visits an if statement node"""
|
||||
|
||||
self.resolve(stmt.condition)
|
||||
self.resolve(stmt.then_branch)
|
||||
if stmt.else_branch:
|
||||
self.resolve(stmt.else_branch)
|
||||
|
||||
def visit_return(self, stmt):
|
||||
"""Visits a return statement node"""
|
||||
|
||||
if self.current_function == FunctionType.NONE:
|
||||
raise JAPLError(stmt.keyword, "'return' outside function")
|
||||
elif self.current_function == FunctionType.INIT:
|
||||
raise JAPLError(stmt.keyword, "Cannot explicitly return from constructor")
|
||||
elif stmt.value is not None:
|
||||
self.resolve(stmt.value)
|
||||
|
||||
def visit_while(self, stmt):
|
||||
"""Visits a while statement node"""
|
||||
|
||||
loop = self.current_loop
|
||||
self.current_loop = LoopType.WHILE
|
||||
self.resolve(stmt.condition)
|
||||
self.resolve(stmt.body)
|
||||
self.current_loop = loop
|
||||
|
||||
def visit_binary(self, expr):
|
||||
"""Visits a binary expression node"""
|
||||
|
||||
self.resolve(expr.left)
|
||||
self.resolve(expr.right)
|
||||
|
||||
def visit_call_expr(self, expr):
|
||||
"""Visits a call expression node"""
|
||||
|
||||
self.resolve(expr.callee)
|
||||
for argument in expr.arguments:
|
||||
self.resolve(argument)
|
||||
|
||||
def visit_grouping(self, expr):
|
||||
"""Visits a grouping expression"""
|
||||
|
||||
self.resolve(expr.expr)
|
||||
|
||||
def visit_literal(self, expr):
|
||||
"""Visits a literal node"""
|
||||
|
||||
return # Literal has no subexpressions and does not reference variables
|
||||
|
||||
def visit_logical(self, expr):
|
||||
"""Visits a logical node"""
|
||||
|
||||
self.visit_binary(expr) # No need to short circuit, so it's the same!
|
||||
|
||||
def visit_unary(self, expr):
|
||||
"""Visits a unary node"""
|
||||
|
||||
self.resolve(expr.right)
|
||||
|
||||
def visit_del(self, stmt):
|
||||
"""Visits a del statement"""
|
||||
|
||||
self.resolve(stmt.name)
|
||||
|
||||
def visit_break(self, stmt):
|
||||
"""Visits a break statement"""
|
||||
|
||||
if self.current_loop == LoopType.NONE:
|
||||
raise JAPLError("'break' outside loop")
|
||||
|
||||
def visit_get(self, expr):
|
||||
"""Visits a property get expression"""
|
||||
|
||||
self.resolve(expr.object)
|
||||
|
||||
def visit_set(self, expr):
|
||||
"""Visits a property set expression"""
|
||||
|
||||
self.resolve(expr.value)
|
||||
self.resolve(expr.object)
|
||||
|
||||
def visit_this(self, expr):
|
||||
"""Visits a 'this' expression"""
|
||||
|
||||
if self.current_class == ClassType.NONE:
|
||||
raise JAPLError(expr.keyword, "'this' outside class")
|
||||
self.resolve_local(expr, expr.keyword)
|
||||
|
||||
def visit_super(self, expr):
|
||||
"""Visits a 'super' expression"""
|
||||
|
||||
if self.current_class == ClassType.NONE:
|
||||
raise JAPLError(expr.keyword, "'super' outside class")
|
||||
self.resolve_local(expr, expr.keyword)
|
||||
|
||||
|
||||
|
|
@ -0,0 +1,11 @@
|
|||
class Callable(object):
|
||||
"""A generic callable"""
|
||||
|
||||
def call(self, interpreter, arguments):
|
||||
raise NotImplementedError
|
||||
|
||||
def __init__(self, arity):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = arity
|
||||
|
||||
|
|
@ -0,0 +1,24 @@
|
|||
from ..meta.exceptions import JAPLError
|
||||
from ..meta.tokenobject import Token
|
||||
|
||||
|
||||
class JAPLInstance:
|
||||
"""A class instance"""
|
||||
|
||||
def __init__(self, klass):
|
||||
self.klass = klass
|
||||
self.fields = {}
|
||||
|
||||
def __repr__(self):
|
||||
return f"<instance of '{self.klass.name}'>"
|
||||
|
||||
def get(self, name: Token):
|
||||
if name.lexeme in self.fields:
|
||||
return self.fields[name.lexeme]
|
||||
meth = self.klass.get_method(name.lexeme)
|
||||
if meth:
|
||||
return meth.bind(self)
|
||||
raise JAPLError(name, f"Undefined property '{name.lexeme}'")
|
||||
|
||||
def set(self, name: Token, value: object):
|
||||
self.fields[name.lexeme] = value
|
||||
|
|
@ -0,0 +1,35 @@
|
|||
from .callable import Callable
|
||||
from .instance import JAPLInstance
|
||||
|
||||
|
||||
class JAPLClass(Callable):
|
||||
"""A JAPL class"""
|
||||
|
||||
def __init__(self, name: str, methods: dict, superclass):
|
||||
self.name = name
|
||||
self.methods = methods
|
||||
self.superclass = superclass
|
||||
if self.get_method("init"):
|
||||
self.arity = self.get_method("init").arity
|
||||
else:
|
||||
self.arity = 0
|
||||
|
||||
def get_method(self, name: str):
|
||||
if name in self.methods:
|
||||
return self.methods[name]
|
||||
superclass = self.superclass
|
||||
while superclass:
|
||||
if name in superclass.methods:
|
||||
return superclass.methods[name]
|
||||
superclass = superclass.superclass
|
||||
|
||||
def __repr__(self):
|
||||
return f"<class '{self.name}'>"
|
||||
|
||||
def call(self, interpreter, arguments):
|
||||
instance = JAPLInstance(self)
|
||||
constructor = self.get_method("init")
|
||||
if constructor:
|
||||
constructor.bind(instance).call(interpreter, arguments)
|
||||
return instance
|
||||
|
||||
|
|
@ -0,0 +1,175 @@
|
|||
from .callable import Callable
|
||||
import time
|
||||
from ..meta.environment import Environment
|
||||
from ..meta.exceptions import ReturnException
|
||||
from .instance import JAPLInstance
|
||||
from .japlclass import JAPLClass
|
||||
|
||||
|
||||
class Clock(Callable):
|
||||
"""JAPL's wrapper around time.time"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 0
|
||||
|
||||
def call(self, *args):
|
||||
return time.time()
|
||||
|
||||
def __repr__(self):
|
||||
return f"<built-in function clock>"
|
||||
|
||||
|
||||
class Type(Callable):
|
||||
"""JAPL's wrapper around type"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 1
|
||||
|
||||
def call(self, _, obj):
|
||||
return type(obj[0])
|
||||
|
||||
def __repr__(self):
|
||||
return f"<built-in function type>"
|
||||
|
||||
|
||||
class Truthy(Callable):
|
||||
"""JAPL's wrapper around bool"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 1
|
||||
|
||||
def call(self, _, obj):
|
||||
return bool(obj[0])
|
||||
|
||||
def __repr__(self):
|
||||
return f"<built-in function truthy>"
|
||||
|
||||
|
||||
class Stringify(Callable):
|
||||
"""JAPL's wrapper around str()"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 1
|
||||
|
||||
def call(self, _, obj):
|
||||
return str(obj[0])
|
||||
|
||||
def __repr__(self):
|
||||
return f"<built-in function stringify>"
|
||||
|
||||
|
||||
class PrintFunction(Callable):
|
||||
"""The print function"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 1
|
||||
|
||||
def call(self, _, *args):
|
||||
print(*args[0])
|
||||
|
||||
def __repr__(self):
|
||||
return "<built-in function print>"
|
||||
|
||||
|
||||
class IsInstance(Callable):
|
||||
"""The isinstance function"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 2
|
||||
|
||||
def call(self, _, args):
|
||||
instance, klass = args
|
||||
if not isinstance(instance, JAPLInstance):
|
||||
return False
|
||||
elif not isinstance(klass, JAPLClass):
|
||||
return False
|
||||
return instance.klass == klass
|
||||
|
||||
def __repr__(self):
|
||||
return "<built-in function isinstance>"
|
||||
|
||||
|
||||
class IsSubclass(Callable):
|
||||
"""The isinstance function"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 2
|
||||
|
||||
def call(self, _, args):
|
||||
first, second = args
|
||||
if not isinstance(first, JAPLClass):
|
||||
return False
|
||||
elif not isinstance(second, JAPLClass):
|
||||
return False
|
||||
return first.superclass == second
|
||||
|
||||
def __repr__(self):
|
||||
return "<built-in function issubclass>"
|
||||
|
||||
|
||||
class IsSuperclass(Callable):
|
||||
"""The isinstance function"""
|
||||
|
||||
def __init__(self, *_):
|
||||
"""Object constructor"""
|
||||
|
||||
self.arity = 2
|
||||
|
||||
def call(self, _, args):
|
||||
first, second = args
|
||||
if not isinstance(first, JAPLClass):
|
||||
return False
|
||||
elif not isinstance(second, JAPLClass):
|
||||
return False
|
||||
return second.superclass == first
|
||||
|
||||
def __repr__(self):
|
||||
return "<built-in function issuperclass>"
|
||||
|
||||
|
||||
class JAPLFunction(Callable):
|
||||
"""A generic wrapper for user-defined functions"""
|
||||
|
||||
def __init__(self, declaration, closure):
|
||||
"""Object constructor"""
|
||||
|
||||
self.declaration = declaration
|
||||
self._repr = f"<function {self.declaration.name.lexeme}>"
|
||||
self.arity = len(self.declaration.params)
|
||||
self.closure = closure
|
||||
|
||||
def bind(self, obj: object):
|
||||
"""Binds a method to an object"""
|
||||
|
||||
env = Environment(self.closure)
|
||||
env.define("this", obj)
|
||||
func = type(self)(self.declaration, env)
|
||||
func._repr = f"<bound method {func.declaration.name.lexeme} of object {obj.klass.name}>"
|
||||
return func
|
||||
|
||||
def call(self, interpreter, arguments):
|
||||
scope = Environment(self.closure)
|
||||
for name, value in zip(self.declaration.params, arguments):
|
||||
scope.define(name.lexeme, value)
|
||||
try:
|
||||
interpreter.execute_block(self.declaration.body, scope)
|
||||
except ReturnException as error:
|
||||
return error.args[0]
|
||||
|
||||
def __repr__(self):
|
||||
return self._repr
|
||||
|
||||
|
|
@ -0,0 +1,69 @@
|
|||
from JAPL.lexer import Lexer
|
||||
from JAPL.meta.exceptions import ParseError, JAPLError
|
||||
from JAPL.resolver import Resolver
|
||||
from JAPL.parser import Parser
|
||||
from JAPL.interpreter import Interpreter
|
||||
|
||||
|
||||
class JAPL(object):
|
||||
"""Wrapper around JAPL's interpreter, lexer and parser"""
|
||||
|
||||
interpreter = Interpreter()
|
||||
resolver = Resolver(interpreter)
|
||||
|
||||
def run(self, file: str):
|
||||
"""Runs a file"""
|
||||
|
||||
if not file:
|
||||
self.repl()
|
||||
else:
|
||||
try:
|
||||
with open(file) as source_file:
|
||||
source_code = source_file.read()
|
||||
lexer = Lexer(source_code)
|
||||
tokens = lexer.lex()
|
||||
parser = Parser(tokens)
|
||||
ast = parser.parse()
|
||||
self.resolver.resolve(ast)
|
||||
self.interpreter.interpret(ast)
|
||||
except FileNotFoundError:
|
||||
print(f"Error: '{file}', no such file or directory")
|
||||
except PermissionError:
|
||||
print(f"Error' '{file}', permission denied")
|
||||
except JAPLError as err:
|
||||
if len(err.args) == 2:
|
||||
token, message = err.args
|
||||
print(f"An exception occurred at line {token.line}, file '{file}' at '{token.lexeme}': {message}")
|
||||
else:
|
||||
print(f"An exception occurred, details below\n\n{type(err).__name__}: {err}")
|
||||
|
||||
def repl(self):
|
||||
"""Starts an interactive REPL"""
|
||||
|
||||
print("[JAPL 0.1.1 - Interactive REPL]")
|
||||
while True:
|
||||
try:
|
||||
source = input(">>> ")
|
||||
except (EOFError, KeyboardInterrupt):
|
||||
print()
|
||||
return
|
||||
if not source:
|
||||
continue
|
||||
lexer = Lexer(source)
|
||||
try:
|
||||
tokens = lexer.lex()
|
||||
ast = Parser(tokens).parse()
|
||||
self.resolver.resolve(ast)
|
||||
result = self.interpreter.interpret(ast)
|
||||
except ParseError as err:
|
||||
if len(err.args) == 2:
|
||||
token, message = err.args
|
||||
print(f"An exception occurred at line {token.line} at '{token.lexeme}': {message}")
|
||||
else:
|
||||
print(f"\nAn exception occurred, details below\n\nParseError: {err.args[0]}")
|
||||
except JAPLError as error:
|
||||
if len(error.args) == 2:
|
||||
token, message = error.args
|
||||
print(f"An exception occurred at line {token.line}, file 'stdin' at '{token.lexeme}': {message}")
|
||||
else:
|
||||
print(f"An exception occurred, details below\n\n{type(error).__name__}: {error}")
|
||||
68
README.md
68
README.md
|
|
@ -1,2 +1,66 @@
|
|||
# japl-python
|
||||
A POC (proof of concept) of the JAPL language written in Python 3
|
||||
# japl
|
||||
JAPL is an interpreted, dynamically-typed, garbage-collected and minimalistic programming language with C- and Java-like syntax.
|
||||
|
||||
# J.. what?
|
||||
|
||||
You may wonder what's the meaning of JAPL: well, it turns out to be an acronym
|
||||
for __Just Another Programming Language__, but beware! Despite the name, the pronounciation is actually the same as "JPL".
|
||||
|
||||
## Some backstory
|
||||
|
||||
JAPL is born thanks to the amazing work of Bob Nystrom that wrote a book available completely for free
|
||||
at [this](https://craftinginterpreters.com) link, where he describes the implementation of a simple language called Lox.
|
||||
|
||||
|
||||
### What has been (or will be) added from Lox
|
||||
|
||||
- Possibility to delete variables with the `del` statement (Currently being reworked)
|
||||
- `break` statement
|
||||
- `continue` statement
|
||||
- Multi-line comments (`/* like this */`)
|
||||
- Nested comments
|
||||
- Modulo division (`%`) and exponentiation (`**`)
|
||||
- `OP_CONSTANT_LONG` is implemented
|
||||
- Differentiation between integers and floating point numbers
|
||||
- `inf` and `nan` types
|
||||
- Possibility to have more than 255 locals in scope at any given time
|
||||
- String slicing, with start:end syntax as well
|
||||
- Strings are not interned (may change in the future)
|
||||
- All entities are actually objects, even builtins
|
||||
- Bitwise operators (AND, OR, XOR, NOT)
|
||||
- Functions default and keyword arguments (__WIP__)
|
||||
- A proper import system (__Coming soon__)
|
||||
- Native asynchronous (`await`/`async fun`) support (__Coming soon__)
|
||||
- Multiple inheritance (__Coming Soon__)
|
||||
- Bytecode optimizations such as constant folding and stack caching (__Coming Soon__)
|
||||
- Arbitrary-precision arithmetic (__Coming soon__)
|
||||
- Generators (__Coming soon__)
|
||||
- A standard library with collections, I/O utilities, scientific modules, etc (__Coming soon__)
|
||||
- Multithreading and multiprocessing support with a global VM Lock like CPython (__Coming soon__)
|
||||
- Multiple GC implementations which can be chosen at runtime or via CLI: bare refcount, refcount + generational GC, M&S (__Coming soon__)
|
||||
- Exceptions (__Coming soon__)
|
||||
- Optional JIT Compilation (__Coming soon__)
|
||||
- Some syntax changes (maybe), e.g. get rid of semicolons
|
||||
- Prototypes based system instead of classes (maybe)
|
||||
|
||||
Other than that, JAPL features closures, function definitions, classes, inheritance and static scoping. You can check
|
||||
the provided example `.jpl` files in the repo to find out more about its syntax.
|
||||
|
||||
### Disclaimer
|
||||
|
||||
This project is currently a WIP (Work in Progress) and is not optimized nor complete.
|
||||
The first version of the interpreter is written in Python, but a bytecode stack-based VM written in nim is being developed right now.
|
||||
|
||||
Also, the design of the language may change at any moment and all the source inside this repo
|
||||
is alpha code quality, for now.
|
||||
|
||||
For other useful information, check the LICENSE file in this repo.
|
||||
|
||||
### Contributing
|
||||
|
||||
If you want to contribute, feel free to send a PR!
|
||||
|
||||
Right now there are some major issues with the virtual machine which need to be addressed
|
||||
before the development can proceed, and some help is ~~desperately needed~~ greatly appreciated!
|
||||
|
||||
You can also contact me using the information available [here](https://github.com/nocturn9x)
|
||||
|
|
|
|||
|
|
@ -0,0 +1,125 @@
|
|||
// Example file to test JAPL's syntax
|
||||
|
||||
// Mathematical expressions
|
||||
|
||||
2 + 2;
|
||||
-1 * 6;
|
||||
3 * (9 / 2); // Parentheses for grouping
|
||||
8 % 2; // Modulo division
|
||||
6 ** 9; // Exponentiation
|
||||
|
||||
// Variable definition and assignment
|
||||
|
||||
var name = "bob"; // Dynamically typed
|
||||
name = "joe"; // Can only be assigned if it's defined
|
||||
del name; // Delete a variable
|
||||
var foo; // Unitialized variables are equal to nil
|
||||
|
||||
// Scoping
|
||||
|
||||
var a = "global";
|
||||
var b = "global1";
|
||||
{ // open a new scope
|
||||
var b = "local"; // Shadow the global variable
|
||||
print a; // This falls back to the global scope
|
||||
print b;
|
||||
}
|
||||
print a;
|
||||
print b; // The outer scope isn't affected
|
||||
|
||||
/*
|
||||
A multiline comment
|
||||
yay!
|
||||
*/
|
||||
|
||||
// Control flow statements
|
||||
|
||||
var n = 0;
|
||||
while (n <= 10) { // While loops
|
||||
if (n <= 5) { // If statements
|
||||
print n;
|
||||
}
|
||||
n = n + 1;
|
||||
}
|
||||
|
||||
for (var i = 0; i < 10; i = i + 1) { // For loops
|
||||
print i;
|
||||
}
|
||||
|
||||
|
||||
// Functions
|
||||
|
||||
print clock(); // Function calls
|
||||
|
||||
fun count(n) { // Function definitions
|
||||
if (n > 1) count(n - 1); // Recursion works
|
||||
print n;
|
||||
}
|
||||
|
||||
count(3);
|
||||
|
||||
// Closures work too!
|
||||
|
||||
var a = "global";
|
||||
{
|
||||
fun showA() {
|
||||
print a;
|
||||
}
|
||||
|
||||
showA();
|
||||
var a = "block";
|
||||
showA();
|
||||
}
|
||||
|
||||
// Nested functions
|
||||
|
||||
fun makeCounter() {
|
||||
var i = 0;
|
||||
fun count() {
|
||||
i = i + 1;
|
||||
print i;
|
||||
}
|
||||
|
||||
return count;
|
||||
}
|
||||
|
||||
var counter = makeCounter();
|
||||
counter(); // "1".
|
||||
counter(); // "2".
|
||||
|
||||
|
||||
// Classes
|
||||
|
||||
class Person {
|
||||
|
||||
init(name) { // Class initializer
|
||||
|
||||
this.name = name;
|
||||
}
|
||||
|
||||
greet() { // Methods don't use the 'fun' keyword!
|
||||
print "Hello, " + this.name;
|
||||
}
|
||||
}
|
||||
|
||||
var bob = Person("Bob"); // Object creation
|
||||
bob.greet(); // Prints Hello, Bob
|
||||
var greetbob = bob.greet; // Functions and methods are first-class objects! (classes are too)
|
||||
greetbob();
|
||||
|
||||
|
||||
class Male < Person { // Male inherits from person
|
||||
|
||||
init(name) {
|
||||
super.init(name); // Inherits constructor behavior
|
||||
this.sex = "male";
|
||||
|
||||
}
|
||||
|
||||
greet() {
|
||||
super.greet(); // Inherits behavior from superclass
|
||||
}
|
||||
}
|
||||
|
||||
var mark = Male("Mark");
|
||||
mark.greet();
|
||||
|
|
@ -0,0 +1,19 @@
|
|||
fun factorial(n) {
|
||||
// Computes the factorial of n iteratively
|
||||
|
||||
if (n < 0) return nil;
|
||||
if (n == 1 or n == 2) return n;
|
||||
var fact = 1;
|
||||
for (var i = 1; i < n + 1; i = i + 1) {
|
||||
fact = fact * i;
|
||||
}
|
||||
return fact;
|
||||
}
|
||||
|
||||
|
||||
var start = clock();
|
||||
print "Computing factorials from 0 to 200";
|
||||
for (var i = 0; i < 201; i = i + 1) factorial(i);
|
||||
var result = clock() - start;
|
||||
print "Computed factorials in " + stringify(result) + " seconds";
|
||||
|
||||
|
|
@ -0,0 +1,12 @@
|
|||
// A recursive implementation of the fibonacci sequence
|
||||
|
||||
fun fib(n) {
|
||||
if (n <= 1) return n;
|
||||
return fib(n - 2) + fib(n - 1);
|
||||
}
|
||||
|
||||
|
||||
var start = clock();
|
||||
fib(30);
|
||||
var end = clock() - start;
|
||||
print(end);
|
||||
|
|
@ -0,0 +1,9 @@
|
|||
import sys
|
||||
from JAPL.wrapper import JAPL
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
if len(sys.argv) == 1:
|
||||
JAPL().repl()
|
||||
else:
|
||||
JAPL().run(sys.argv[1])
|
||||
|
|
@ -0,0 +1 @@
|
|||
singledispatchmethod
|
||||
|
|
@ -0,0 +1,16 @@
|
|||
import setuptools
|
||||
|
||||
setuptools.setup(
|
||||
name="JAPL - Just another programming language",
|
||||
version="0.1.1",
|
||||
author="nocturn9x",
|
||||
author_email="nocturn9x@intellivoid.net",
|
||||
description="The JAPL programming language",
|
||||
packages=setuptools.find_packages(),
|
||||
classifiers=[
|
||||
"Programming Language :: Python :: 3",
|
||||
"License :: OSI Approved :: MIT License",
|
||||
"Operating System :: OS Independent",
|
||||
],
|
||||
python_requires='>=3.6',
|
||||
)
|
||||
Loading…
Reference in New Issue