Read an expression from a sequence of tokens.
(tokens: list[str])
| 33 | return s.replace('(', ' ( ').replace(')', ' ) ').split() |
| 34 | |
| 35 | def read_from_tokens(tokens: list[str]) -> Expression: |
| 36 | "Read an expression from a sequence of tokens." |
| 37 | if len(tokens) == 0: |
| 38 | raise SyntaxError('unexpected EOF while reading') |
| 39 | token = tokens.pop(0) |
| 40 | if '(' == token: |
| 41 | exp = [] |
| 42 | while tokens[0] != ')': |
| 43 | exp.append(read_from_tokens(tokens)) |
| 44 | tokens.pop(0) # discard ')' |
| 45 | return exp |
| 46 | elif ')' == token: |
| 47 | raise SyntaxError('unexpected )') |
| 48 | else: |
| 49 | return parse_atom(token) |
| 50 | |
| 51 | def parse_atom(token: str) -> Atom: |
| 52 | "Numbers become numbers; every other token is a symbol." |
no test coverage detected