54 lines
1.7 KiB
Python
54 lines
1.7 KiB
Python
from smnp.ast.node.list import ListNode, ListItemNode, CloseListNode
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from smnp.ast.parsers.expression import parseExpression
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from smnp.ast.tools import greedy, assertToken
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from smnp.token.type import TokenType
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# list -> CLOSE_PAREN | expr listTail
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def parseList(input, parent):
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if input.isCurrent(TokenType.OPEN_PAREN):
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node = ListNode(parent, input.current().pos)
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input.ahead()
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# list -> CLOSE_PAREN (end of list)
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if input.isCurrent(TokenType.CLOSE_PAREN):
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close = CloseListNode(node, input.current().pos)
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node.append(close)
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input.ahead()
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return node
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# list -> expr listTail
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if input.hasCurrent():
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token = input.current()
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expr = greedy(parseExpression)(input, parent)
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item = ListItemNode(expr, node, token.pos)
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expr.parent = item
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node.append(item)
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listTail = parseListTail(input, item)
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item.append(listTail)
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return node
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return None
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# listTail -> COMMA expr listTail | CLOSE_PAREN
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def parseListTail(input, parent):
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# listTail -> CLOSE_PAREN
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if input.isCurrent(TokenType.CLOSE_PAREN):
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close = CloseListNode(parent, input.current().pos)
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input.ahead()
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return close
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# listTail -> COMMA expr listTail
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if input.hasCurrent() and input.hasMore():
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assertToken(TokenType.COMMA, input)
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input.ahead()
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expr = greedy(parseExpression)(input, parent)
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if expr is not None:
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item = ListItemNode(expr, parent, expr.pos)
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expr.parent = item
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listTail = parseListTail(input, item)
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item.append(listTail)
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listTail.parent = item
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return item
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return None |