- A stack is maintained by the lexer to keep track of indentations. A count is accumulated for the number of whitespace characters before the first token. If the count changes from the previous line count, a stack operation is performed. If count increases, another value is added to the stack. If count decreases, the topmost value is popped from the stack.
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## Challenges:
- Shift-reduce errors while parsing the grammar. One approach to fix is to change the grammar. We chose to fix this issue by adding a precedence as in the case of expr by adding right precedence for if and else.
- Handling errors was another challenge. This required debugging and small changes to program flow.
sunyinqi0508
4 years ago
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