initial commit
This commit is contained in:
Mattia
GitHub
parent
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commit
1daae9c30a
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import operator
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from typing import List
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from .types.callable import Callable
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from .types.japlclass import JAPLClass
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from .types.instance import JAPLInstance
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from .meta.environment import Environment
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from .meta.tokentype import TokenType
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from .meta.exceptions import JAPLError, BreakException, ReturnException
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from .types.native import Clock, Type, JAPLFunction, Truthy, Stringify, PrintFunction, IsInstance, IsSubclass, IsSuperclass
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from .meta.expression import Expression, Variable, Literal, Logical, Binary, Unary, Grouping, Assignment, Call, Get, Set
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from .meta.statement import Statement, StatementExpr, If, While, Del, Break, Return, Var, Block, Function, Class
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class Interpreter(Expression.Visitor, Statement.Visitor):
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"""
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An interpreter for the JAPL
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programming language
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"""
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OPS = {TokenType.MINUS: operator.sub, TokenType.PLUS: operator.add, TokenType.SLASH: operator.truediv,
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TokenType.STAR: operator.mul, TokenType.DEQ: operator.eq, TokenType.GT: operator.gt,
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TokenType.GE: operator.ge, TokenType.LT: operator.lt, TokenType.LE: operator.le, TokenType.EQ: operator.eq,
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TokenType.NE: operator.ne, TokenType.MOD: operator.mod, TokenType.POW: operator.pow}
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def __init__(self):
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"""Object constructor"""
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self.environment = Environment()
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self.locals = {}
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self.globals = self.environment
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self.globals.define("clock", Clock())
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self.globals.define("type", Type())
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self.globals.define("truthy", Truthy())
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self.globals.define("stringify", Stringify())
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self.globals.define("print", PrintFunction())
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self.globals.define("isinstance", IsInstance())
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self.globals.define("issuperclass", IsSuperclass())
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self.globals.define("issubclass", IsSubclass())
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def number_operand(self, op, operand):
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"""
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An helper method to check if the operand
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to a unary operator is a number
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"""
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if isinstance(operand, (int, float)):
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return
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raise JAPLError(op,
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f"Unsupported unary operator '{op.lexeme}' for object of type '{type(operand).__name__}'")
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def compatible_operands(self, op, left, right):
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"""
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Helper method to check types when doing binary
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operations
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"""
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if op.kind == TokenType.SLASH and right == 0:
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raise JAPLError(op, "Cannot divide by 0")
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elif isinstance(left, (bool, type(None))) or isinstance(right, (bool, type(None))):
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if op.kind not in (TokenType.DEQ, TokenType.NE):
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raise JAPLError(op, f"Unsupported binary operator '{op.lexeme}' for objects of type '{type(left).__name__}' and '{type(right).__name__}'")
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return
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elif isinstance(left, (int, float)) and isinstance(right, (int, float)):
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return
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elif op.kind in (TokenType.PLUS, TokenType.STAR, TokenType.DEQ, TokenType.NE):
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if isinstance(left, str) and isinstance(right, str):
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return
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elif isinstance(left, str) and isinstance(right, int):
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return
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elif isinstance(left, int) and isinstance(right, str):
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return
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raise JAPLError(operator, f"Unsupported binary operator '{op.lexeme}' for objects of type '{type(left).__name__}' and '{type(right).__name__}'")
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def visit_literal(self, expr: Literal):
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"""
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Visits a Literal node in the Abstract Syntax Tree,
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returning its value to the visitor
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"""
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return expr.value
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def visit_logical(self, expr: Logical):
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"""Visits a logical node"""
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left = self.eval(expr.left)
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if expr.operator.kind == TokenType.OR:
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if bool(left):
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return left
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elif not bool(left):
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return self.eval(expr.right)
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return self.eval(expr.right)
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def eval(self, expr: Expression):
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"""
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Evaluates an expression by calling its accept()
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method and passing self to it. This mechanism is known
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as the 'Visitor Pattern': the expression object will
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later call the interpreter's appropriate method to
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evaluate itself
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"""
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return expr.accept(self)
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def visit_grouping(self, grouping: Grouping):
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"""
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Visits a Grouping node in the Abstract Syntax Tree,
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recursively evaluating its subexpressions
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"""
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return self.eval(grouping.expr)
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def visit_unary(self, expr: Unary):
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"""
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Visits a Unary node in the Abstract Syntax Teee,
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returning the negation of the given object, if
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the operation is supported
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"""
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right = self.eval(expr.right)
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self.number_operand(expr.operator, right)
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if expr.operator.kind == TokenType.NEG:
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return not right
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return -right
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def visit_binary(self, expr: Binary):
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"""
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Visits a Binary node in the Abstract Syntax Tree,
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recursively evaulating both operands first and then
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performing the operation specified by the operator
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"""
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left = self.eval(expr.left)
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right = self.eval(expr.right)
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self.compatible_operands(expr.operator, left, right)
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return self.OPS[expr.operator.kind](left, right)
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def visit_statement_expr(self, stmt: StatementExpr):
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"""
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Visits an expression statement and evaluates it
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"""
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self.eval(stmt.expression)
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def visit_if(self, statement: If):
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"""
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Visits an If node and evaluates it
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"""
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if self.eval(statement.condition):
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self.exec(statement.then_branch)
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elif statement.else_branch:
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self.exec(statement.else_branch)
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def visit_class(self, stmt: Class):
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"""Visits a class declaration"""
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superclass = None
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if stmt.superclass:
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superclass = self.eval(stmt.superclass)
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if not isinstance(superclass, JAPLClass):
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raise JAPLError(stmt.superclass.name, "Superclass must be a class")
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self.environment.define(stmt.name.lexeme, None)
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if superclass:
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environment = Environment(self.environment)
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environment.define("super", superclass)
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else:
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environment = self.environment
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methods = {}
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for method in stmt.methods:
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func = JAPLFunction(method, environment)
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methods[method.name.lexeme] = func
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klass = JAPLClass(stmt.name.lexeme, methods, superclass)
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if superclass:
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self.environment = environment.enclosing
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self.environment.assign(stmt.name, klass)
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def visit_while(self, statement: While):
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"""
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Visits a while node and executes it
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"""
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while self.eval(statement.condition):
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try:
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self.exec(statement.body)
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except BreakException:
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break
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def visit_var_stmt(self, stmt: Var):
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"""
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Visits a var statement
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"""
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val = None
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if stmt.init:
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val = self.eval(stmt.init)
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self.environment.define(stmt.name.lexeme, val)
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def lookup(self, name, expr: Expression):
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"""
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Performs name lookups in the closest scope
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"""
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distance = self.locals.get(expr)
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if distance is not None:
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return self.environment.get_at(distance, name.lexeme)
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else:
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return self.globals.get(name)
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def visit_var_expr(self, expr: Variable):
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"""
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Visits a var expression
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"""
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return self.lookup(expr.name, expr)
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def visit_del(self, stmt: Del):
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"""
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Visits a del expression
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"""
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return self.environment.delete(stmt.name)
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def visit_assign(self, stmt: Assignment):
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"""
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Visits an assignment expression
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"""
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right = self.eval(stmt.value)
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distance = self.locals.get(stmt)
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if distance is not None:
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self.environment.assign_at(distance, stmt.name, right)
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else:
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self.globals.assign(stmt.name, right)
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return right
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def visit_block(self, stmt: Block):
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"""
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Visits a new scope block
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"""
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return self.execute_block(stmt.statements, Environment(self.environment))
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def visit_break(self, stmt: Break):
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"""
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Visits a break statement
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"""
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raise BreakException()
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def visit_call_expr(self, expr: Call):
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"""
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Visits a call expression
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"""
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callee = self.eval(expr.callee)
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if not isinstance(callee, Callable):
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raise JAPLError(expr.paren, f"'{type(callee).__name__}' is not callable")
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arguments = []
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for argument in expr.arguments:
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arguments.append(self.eval(argument))
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function = callee
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if function.arity != len(arguments):
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raise JAPLError(expr.paren, f"Expecting {function.arity} arguments, got {len(arguments)}")
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return function.call(self, arguments)
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def execute_block(self, statements: List[Statement], scope: Environment):
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"""
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Executes a block of statements
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"""
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prev = self.environment
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try:
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self.environment = scope
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for statement in statements:
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self.exec(statement)
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finally:
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self.environment = prev
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def visit_return(self, statement: Return):
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"""
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Visits a return statement
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"""
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value = None
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if statement.value:
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value = self.eval(statement.value)
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raise ReturnException(value)
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def visit_function(self, statement: Function):
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"""
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Visits a function
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"""
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function = JAPLFunction(statement, self.environment)
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self.environment.define(statement.name.lexeme, function)
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def visit_get(self, expr: Get):
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"""Visits property get expressions and evaluates them"""
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obj = self.eval(expr.object)
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if isinstance(obj, JAPLInstance):
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return obj.get(expr.name)
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raise JAPLError(expr.name, "Only instances have properties")
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def visit_set(self, expr: Set):
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"""Visits property set expressions and evaluates them"""
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obj = self.eval(expr.object)
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if not isinstance(obj, JAPLInstance):
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raise JAPLError(expr, "Only instances have fields")
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value = self.eval(expr.value)
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obj.set(expr.name, value)
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def visit_this(self, expr):
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"""Evaluates 'this' expressions"""
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return self.lookup(expr.keyword, expr)
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def visit_super(self, expr):
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"""Evaluates 'super' expressions"""
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distance = self.locals.get(expr)
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superclass = self.environment.get_at(distance, "super")
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instance = self.environment.get_at(distance - 1, "this")
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meth = superclass.get_method(expr.method.lexeme)
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if not meth:
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raise JAPLError(expr.method, f"Undefined property '{expr.method.lexeme}'")
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return meth.bind(instance)
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def exec(self, statement: Statement):
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"""
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Executes a statement
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"""
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statement.accept(self)
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def interpret(self, statements: List[Statement]):
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"""
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Executes a JAPL program
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"""
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for statement in statements:
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self.exec(statement)
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def resolve(self, expr: Expression, depth: int):
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"""
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Stores the result of the name resolution: this
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info will be used later to know exactly in which
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environment to look up a given variable
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"""
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self.locals[expr] = depth # How many environments to skip!
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@ -0,0 +1,212 @@
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from .meta.tokenobject import Token
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from .meta.tokentype import TokenType
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from .meta.exceptions import ParseError
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from typing import List
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class Lexer(object):
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"""
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A simple tokenizer for the JAPL programming
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language, scans a input source file and
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produces a list of tokens. Some errors
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are caught here as well.
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"""
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TOKENS = {"(": TokenType.LP, ")": TokenType.RP,
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"{": TokenType.LB, "}": TokenType.RB,
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".": TokenType.DOT, ",": TokenType.COMMA,
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"-": TokenType.MINUS, "+": TokenType.PLUS,
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";": TokenType.SEMICOLON, "*": TokenType.STAR,
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">": TokenType.GT, "<": TokenType.LT,
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"=": TokenType.EQ, "!": TokenType.NEG,
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"/": TokenType.SLASH, "%": TokenType.MOD}
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RESERVED = {"or": TokenType.OR, "and": TokenType.AND,
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"class": TokenType.CLASS, "fun": TokenType.FUN,
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"if": TokenType.IF, "else": TokenType.ELSE,
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"for": TokenType.FOR, "while": TokenType.WHILE,
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"var": TokenType.VAR, "nil": TokenType.NIL,
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"true": TokenType.TRUE, "false": TokenType.FALSE,
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"return": TokenType.RETURN,
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"this": TokenType.THIS, "super": TokenType.SUPER,
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"del": TokenType.DEL, "break": TokenType.BREAK}
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def __init__(self, source: str):
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"""Object constructor"""
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self.source = source
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self.tokens: List[Token] = []
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self.line: int = 1 # Points to the line being lexed
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self.start: int = 0 # The position of the first character of the current lexeme
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self.current: int = 0 # The position of the current character being lexed
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def step(self) -> str:
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"""
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'Steps' one character in the source code and returns it
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"""
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if self.done():
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return ""
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self.current += 1
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return self.source[self.current - 1]
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def peek(self) -> str:
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"""
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Returns the current character without consuming it
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or an empty string if all text has been consumed
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"""
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if self.done():
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return ""
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return self.source[self.current]
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def peek_next(self) -> str:
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"""
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Returns the next character after self.current
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or an empty string if the input has been consumed
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"""
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if self.current + 1 >= len(self.source):
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return ""
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return self.source[self.current + 1]
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def string(self, delimiter: str):
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"""Parses a string literal"""
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while self.peek() != delimiter and not self.done():
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if self.peek() == "\n":
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self.line += 1
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self.step()
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if self.done():
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raise ParseError(f"unterminated string literal at line {self.line}")
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self.step() # Consume the '"'
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value = self.source[self.start + 1:self.current - 1] # Get the actual string
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self.tokens.append(self.create_token(TokenType.STR, value))
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def number(self):
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"""Parses a number literal"""
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convert = int
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while self.peek().isdigit():
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self.step()
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if self.peek() == ".":
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self.step() # Consume the "."
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while self.peek().isdigit():
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self.step()
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convert = float
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self.tokens.append(self.create_token(TokenType.NUM,
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convert(self.source[self.start:self.current])))
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def identifier(self):
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"""Parses identifiers and reserved keywords"""
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while self.peek().isalnum() or self.is_identifier(self.peek()):
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self.step()
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kind = TokenType.ID
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value = self.source[self.start:self.current]
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if self.RESERVED.get(value, None):
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kind = self.RESERVED[value]
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self.tokens.append(self.create_token(kind))
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def comment(self):
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"""Handles multi-line comments"""
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closed = False
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while not self.done():
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end = self.peek() + self.peek_next()
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if end == "/*": # Nested comments
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self.step()
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self.step()
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self.comment()
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elif end == "*/":
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closed = True
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self.step() # Consume the two ends
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self.step()
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break
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self.step()
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if self.done() and not closed:
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raise ParseError(f"Unexpected EOF at line {self.line}")
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def match(self, char: str) -> bool:
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"""
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Returns True if the current character in self.source matches
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the given character
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"""
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if self.done():
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return False
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elif self.source[self.current] != char:
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return False
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self.current += 1
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return True
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def done(self) -> bool:
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"""
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Helper method that's used by the lexer
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to know if all source has been consumed
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"""
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return self.current >= len(self.source)
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def create_token(self, kind: TokenType, literal: object = None) -> Token:
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"""
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Creates and returns a token object
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"""
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return Token(kind, self.source[self.start:self.current], literal, self.line)
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|
||||
def is_identifier(self, char: str):
|
||||
"""Returns if a character can be an identifier"""
|
||||
|
||||
if char.isalpha() or char in ("_", ): # More coming soon
|
||||
return True
|
||||
|
||||
def scan_token(self):
|
||||
"""
|
||||
Scans for a single token and adds it to
|
||||
self.tokens
|
||||
"""
|
||||
|
||||
char = self.step()
|
||||
if char in (" ", "\t", "\r"): # Useless characters
|
||||
return
|
||||
elif char == "\n": # New line
|
||||
self.line += 1
|
||||
elif char in ("'", '"'): # A string literal
|
||||
self.string(char)
|
||||
elif char.isdigit():
|
||||
self.number()
|
||||
elif self.is_identifier(char): # Identifier or reserved keyword
|
||||
self.identifier()
|
||||
elif char in self.TOKENS:
|
||||
if char == "/" and self.match("/"):
|
||||
while self.peek() != "\n" and not self.done():
|
||||
self.step() # Who cares about comments?
|
||||
elif char == "/" and self.match("*"):
|
||||
self.comment()
|
||||
elif char == "=" and self.match("="):
|
||||
self.tokens.append(self.create_token(TokenType.DEQ))
|
||||
elif char == ">" and self.match("="):
|
||||
self.tokens.append(self.create_token(TokenType.GE))
|
||||
elif char == "<" and self.match("="):
|
||||
self.tokens.append(self.create_token(TokenType.LE))
|
||||
elif char == "!" and self.match("="):
|
||||
self.tokens.append(self.create_token(TokenType.NE))
|
||||
elif char == "*" and self.match("*"):
|
||||
self.tokens.append(self.create_token(TokenType.POW))
|
||||
else:
|
||||
self.tokens.append(self.create_token(self.TOKENS[char]))
|
||||
else:
|
||||
raise ParseError(f"unexpected character '{char}' at line {self.line}")
|
||||
|
||||
def lex(self) -> List[Token]:
|
||||
"""
|
||||
Performs lexical analysis on self.source
|
||||
and returns a list of tokens
|
||||
"""
|
||||
|
||||
while not self.done():
|
||||
self.start = self.current
|
||||
self.scan_token()
|
||||
self.tokens.append(Token(TokenType.EOF, "", None, self.line))
|
||||
return self.tokens
|
||||
|
|
@ -0,0 +1,7 @@
|
|||
from enum import Enum, auto
|
||||
|
||||
|
||||
class ClassType(Enum):
|
||||
|
||||
NONE = auto()
|
||||
CLASS = auto()
|
||||
|
|
@ -0,0 +1,71 @@
|
|||
from .exceptions import JAPLError
|
||||
from .tokenobject import Token
|
||||
from .expression import Variable
|
||||
|
||||
|
||||
class Environment(object):
|
||||
"""
|
||||
A wrapper around a hashmap representing
|
||||
a scope
|
||||
"""
|
||||
|
||||
def __init__(self, enclosing=None):
|
||||
"""Object constructor"""
|
||||
|
||||
self.map = {}
|
||||
self.enclosing = enclosing
|
||||
|
||||
def define(self, name: str, attr: object):
|
||||
"""Defines a new variable in the scope"""
|
||||
|
||||
self.map[name] = attr
|
||||
|
||||
def get(self, name: Token):
|
||||
"""Gets a variable"""
|
||||
|
||||
if name.lexeme in self.map:
|
||||
return self.map[name.lexeme]
|
||||
elif self.enclosing:
|
||||
return self.enclosing.get(name)
|
||||
raise JAPLError(name, f"Undefined name '{name.lexeme}'")
|
||||
|
||||
def get_at(self, distance, name):
|
||||
"""Gets a variable in a specific scope"""
|
||||
|
||||
return self.ancestor(distance).map.get(name)
|
||||
|
||||
def ancestor(self, distance):
|
||||
"""Finds the scope specified by distance"""
|
||||
|
||||
env = self
|
||||
for _ in range(distance):
|
||||
env = env.enclosing
|
||||
return env
|
||||
|
||||
def assign_at(self, distance, name, value):
|
||||
"""Same as get_at, but assigns instead of retrieving"""
|
||||
|
||||
self.ancestor(distance).map[name.lexeme] = value
|
||||
|
||||
def delete(self, var):
|
||||
"""Deletes a variable"""
|
||||
|
||||
if var.name.lexeme in self.map:
|
||||
del self.map[var.name.lexeme]
|
||||
elif self.enclosing:
|
||||
self.enclosing.delete(var)
|
||||
else:
|
||||
raise JAPLError(var.name, f"Undefined name '{var.name.lexeme}'")
|
||||
|
||||
def assign(self, name: Token, value: object):
|
||||
"""Assigns a variable"""
|
||||
|
||||
if name.lexeme in self.map:
|
||||
if isinstance(value, Variable):
|
||||
self.map[name.lexeme] = self.get(value.name)
|
||||
else:
|
||||
self.map[name.lexeme] = value
|
||||
elif self.enclosing:
|
||||
self.enclosing.assign(name, value)
|
||||
else:
|
||||
raise JAPLError(name, f"Undefined name '{name.lexeme}'")
|
||||
|
|
@ -0,0 +1,32 @@
|
|||
from .tokentype import TokenType
|
||||
|
||||
|
||||
class JAPLError(BaseException):
|
||||
"""JAPL's exceptions base class"""
|
||||
|
||||
def __repr__(self):
|
||||
return self.args[1]
|
||||
|
||||
|
||||
class ParseError(JAPLError):
|
||||
"""An error occurred while parsing"""
|
||||
|
||||
def __repr__(self):
|
||||
if len(self.args) > 1:
|
||||
message, token = self.args
|
||||
if token.kind == TokenType.EOF:
|
||||
return f"Unexpected error while parsing at line {token.line}, at end: {message}"
|
||||
else:
|
||||
return f"Unexpected error while parsing at line {token.line} at '{token.lexeme}': {message}"
|
||||
return self.args[0]
|
||||
|
||||
def __str__(self):
|
||||
return self.__repr__()
|
||||
|
||||
|
||||
class BreakException(JAPLError):
|
||||
"""Notifies a loop that it's time to break"""
|
||||
|
||||
|
||||
class ReturnException(JAPLError):
|
||||
"""Notifies a function that it's time to return"""
|
||||
|
|
@ -0,0 +1,167 @@
|
|||
from dataclasses import dataclass
|
||||
from abc import ABC, abstractmethod
|
||||
from .tokenobject import Token
|
||||
from typing import List
|
||||
|
||||
|
||||
class Expression(object):
|
||||
"""
|
||||
An object representing a JAPL expression.
|
||||
This class is not meant to be instantiated directly,
|
||||
inherit from it instead!
|
||||
"""
|
||||
|
||||
def accept(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
class Visitor(ABC):
|
||||
"""
|
||||
Visitor abstract base class to implement
|
||||
the Visitor pattern
|
||||
"""
|
||||
|
||||
@abstractmethod
|
||||
def visit_literal(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_binary(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_grouping(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_unary(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@staticmethod
|
||||
def visit_get(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@staticmethod
|
||||
def visit_set(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
|
||||
@dataclass
|
||||
class Binary(Expression):
|
||||
left: Expression
|
||||
operator: Token
|
||||
right: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_binary(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Unary(Expression):
|
||||
operator: Token
|
||||
right: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_unary(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Literal(Expression):
|
||||
value: object
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_literal(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Grouping(Expression):
|
||||
expr: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_grouping(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Variable(Expression):
|
||||
name: Token
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_var_expr(self)
|
||||
|
||||
def __hash__(self):
|
||||
return super().__hash__()
|
||||
|
||||
|
||||
@dataclass
|
||||
class Assignment(Expression):
|
||||
name: Token
|
||||
value: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_assign(self)
|
||||
|
||||
def __hash__(self):
|
||||
return super().__hash__()
|
||||
|
||||
|
||||
@dataclass
|
||||
class Logical(Expression):
|
||||
left: Expression
|
||||
operator: Token
|
||||
right: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_logical(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Call(Expression):
|
||||
callee: Expression
|
||||
paren: Token
|
||||
arguments: List[Expression] = ()
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_call_expr(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Get(Expression):
|
||||
object: Expression
|
||||
name: Token
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_get(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Set(Expression):
|
||||
object: Expression
|
||||
name: Token
|
||||
value: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_set(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class This(Expression):
|
||||
keyword: Token
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_this(self)
|
||||
|
||||
def __hash__(self):
|
||||
return super().__hash__()
|
||||
|
||||
|
||||
@dataclass
|
||||
class Super(Expression):
|
||||
keyword: Token
|
||||
method: Token
|
||||
|
||||
def accept(self, visitor):
|
||||
return visitor.visit_super(self)
|
||||
|
||||
def __hash__(self):
|
||||
return super().__hash__()
|
||||
|
||||
|
||||
|
|
@ -0,0 +1,8 @@
|
|||
from enum import Enum, auto
|
||||
|
||||
|
||||
class FunctionType(Enum):
|
||||
NONE = auto()
|
||||
FUNCTION = auto()
|
||||
METHOD = auto()
|
||||
INIT = auto()
|
||||
|
|
@ -0,0 +1,7 @@
|
|||
from enum import Enum, auto
|
||||
|
||||
|
||||
class LoopType(Enum):
|
||||
|
||||
NONE = auto()
|
||||
WHILE = auto()
|
||||
|
|
@ -0,0 +1,173 @@
|
|||
from abc import ABC, abstractmethod
|
||||
from dataclasses import dataclass
|
||||
from .expression import Expression, Variable
|
||||
from .tokenobject import Token
|
||||
from typing import List, Any
|
||||
|
||||
|
||||
class Statement(object):
|
||||
"""
|
||||
A Base Class representing JAPL statements
|
||||
"""
|
||||
|
||||
def accept(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
class Visitor(ABC):
|
||||
"""Wrapper to implement the Visitor Pattern"""
|
||||
|
||||
|
||||
@abstractmethod
|
||||
def visit_statement_expr(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_var_stmt(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_del(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_block(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_if(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_while(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_break(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_function(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@abstractmethod
|
||||
def visit_return(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
@staticmethod
|
||||
def visit_class(self, visitor):
|
||||
raise NotImplementedError
|
||||
|
||||
|
||||
@dataclass
|
||||
class StatementExpr(Statement):
|
||||
"""
|
||||
An expression statement
|
||||
"""
|
||||
|
||||
expression: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_statement_expr(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Var(Statement):
|
||||
"""
|
||||
A var statement
|
||||
"""
|
||||
|
||||
name: Token
|
||||
init: Expression = None
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_var_stmt(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Del(Statement):
|
||||
"""
|
||||
A del statement
|
||||
"""
|
||||
|
||||
name: Any
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_del(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Block(Statement):
|
||||
"""A block statement"""
|
||||
|
||||
statements: List[Statement]
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_block(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class If(Statement):
|
||||
"""An if statement"""
|
||||
|
||||
condition: Expression
|
||||
then_branch: Statement
|
||||
else_branch: Statement
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_if(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class While(Statement):
|
||||
"""A while statement"""
|
||||
|
||||
condition: Expression
|
||||
body: Statement
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_while(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Break(Statement):
|
||||
"""A break statement"""
|
||||
|
||||
token: Token
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_break(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Function(Statement):
|
||||
"""A function statement"""
|
||||
|
||||
name: Token
|
||||
params: List[Token]
|
||||
body: List[Statement]
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_function(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Return(Statement, BaseException):
|
||||
"""A return statement"""
|
||||
|
||||
keyword: Token
|
||||
value: Expression
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_return(self)
|
||||
|
||||
|
||||
@dataclass
|
||||
class Class(Statement):
|
||||
"""A class statement"""
|
||||
|
||||
name: Token
|
||||
methods: list
|
||||
superclass: Variable
|
||||
|
||||
def accept(self, visitor):
|
||||
visitor.visit_class(self)
|
||||
|
|
@ -0,0 +1,13 @@
|
|||
from dataclasses import dataclass
|
||||
from .tokentype import TokenType
|
||||
|
||||
@dataclass
|
||||
class Token(object):
|
||||
"""The representation of a JAPL token"""
|
||||
|
||||
kind: TokenType
|
||||
lexeme: str
|
||||
literal: object
|
||||
line: int
|
||||
|
||||
|
||||
|
|
@ -0,0 +1,55 @@
|
|||
from enum import Enum, auto
|
||||
|
||||
class TokenType(Enum):
|
||||
"""
|
||||
An enumeration for all JAPL types
|
||||
"""
|
||||
|
||||
LP = auto()
|
||||
RP = auto()
|
||||
LB = auto()
|
||||
RB = auto()
|
||||
COMMA = auto()
|
||||
DOT = auto()
|
||||
PLUS = auto()
|
||||
MINUS = auto()
|
||||
SLASH = auto()
|
||||
SEMICOLON = auto()
|
||||
STAR = auto()
|
||||
|
||||
|
||||
NEG = auto()
|
||||
NE = auto()
|
||||
EQ = auto()
|
||||
DEQ = auto()
|
||||
GT = auto()
|
||||
LT = auto()
|
||||
GE = auto()
|
||||
LE = auto()
|
||||
MOD = auto()
|
||||
POW = auto()
|
||||
|
||||
ID = auto()
|
||||
STR = auto()
|
||||
NUM = auto()
|
||||
|
||||
|
||||
AND = auto()
|
||||
CLASS = auto()
|
||||
ELSE = auto()
|
||||
FOR = auto()
|
||||
FUN = auto()
|
||||
FALSE = auto()
|
||||
IF = auto()
|
||||
NIL = auto()
|
||||
OR = auto()
|
||||
RETURN = auto()
|
||||
SUPER = auto()
|
||||
THIS = auto()
|
||||
TRUE = auto()
|
||||
VAR = auto()
|
||||
WHILE = auto()
|
||||
DEL = auto()
|
||||
BREAK = auto()
|
||||
|
||||
EOF = auto()
|
||||
Loading…
Reference in New Issue