- 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.
- 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.
- The file: src/main/jflex/chocopy/pa1/ChocoPy.jflex, lines from 100 to 182, contain the code for the stack.
- Line 270 of the same file deals with additional dedents in case the input ends in an indented state.
## Challenges:
## 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.
- 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.
Sanjar Ahmadov
4 years ago