def parse_if_expr(self):
expr = ast.IfExpression(self.cur_tok, None, None, None)
if not self.expect(token.LPAREN):
return None
self.next()
expr.condition = self.parse_expr(LOWEST)
if not self.expect(token.RPAREN):
return None
if not self.expect(token.LBRACE):
return None
expr.consequence = self.parse_block_statement()
if self.peek_is(token.ELSE):
self.next()
if not self.expect(token.LBRACE):
return None
expr.alternative = self.parse_block_statement()
elif self.peek_is(token.ELIF):
self.next()
expr.alternative = ast.BlockStatement(
self.cur_tok,
[ast.ExpressionStatement(self.cur_tok, self.parse_if_expr())])
return expr
def parseIfExpression(self): expression = ast.IfExpression() expression.Token = self.curToken if not self.expectPeek(token.LPAREN): return None self.nextToken() expression.Condition = self.parseExpression(LOWEST) if not self.expectPeek(token.RPAREN): return None if not self.expectPeek(token.LBRACE): return None expression.Consequence = self.parseBlockStatement() if self.peekTokenIs(token.ELSE): self.nextToken() if not self.expectPeek(token.LBRACE): return None expression.Alternative = self.parseBlockStatement() return expression
def parseIFExpression(self):
ifExp = ast.IfExpression(self.currToken)
if not self.expectedPeekToken(tkn.LPAREN):
return None
self.nextToken()
ifExp.Condition = self.parseExpression(Precedence.LOWEST)
if not self.expectedPeekToken(tkn.RPAREN):
return None
if not self.expectedPeekToken(tkn.LBRACE):
return None
ifExp.Consequence = self.parseBlockStatement()
if self.peekTokenIs(tkn.ELSE):
self.nextToken()
if not self.expectedPeekToken(tkn.LBRACE):
return None
ifExp.Alternative = self.parseBlockStatement()
return ifExp
def _parse_if_expression(self) -> Optional[ast.IfExpression]:
token = self._current_token
if not self._expect_peek(TokenType.LPAREN):
return None
self._next_token()
condition = self._parse_expression(PrecedenceLevel.LOWEST)
if condition is None:
return None
if not self._expect_peek(TokenType.RPAREN):
return None
if not self._expect_peek(TokenType.LBRACE):
return None
consequence = self._parse_block_statement()
alternative = None
if self._peek_token_is(TokenType.ELSE):
self._next_token()
if not self._expect_peek(TokenType.LBRACE):
return None
alternative = self._parse_block_statement()
return ast.IfExpression(token, condition, consequence, alternative)
def ifExpr(self):
l = self._nextTag(IF)
self._nextTag(LPAREN)
condExpr = self.expr()
self._nextTag(RPAREN)
trueExpr = self.expr()
if self._peekHang() is ELSE:
self._next() # newline
self._next() # else
falseExpr = self.expr()
elif self._peekTag() is ELSE:
self._next()
falseExpr = self.expr()
else:
falseExpr = None
e = ast.IfExpression(condExpr, trueExpr, falseExpr, None,
self._location(l.location))
self._liftComments(e, None,
falseExpr if falseExpr is not None else trueExpr)
return e
def expr_if(s):
return ast.IfExpression(s[2], s[5])