| # Grammar for Python |
| |
| # Change log: |
| |
| # 06-Apr-92: |
| # Use only '*' for varargs list |
| |
| # 31-Mar-92: |
| # Tighten syntax for try statements |
| |
| # 27-Feb-92: |
| # Allow NEWLINE* after eval input |
| |
| # 16-Jan-92: |
| # Added '*' as alternative for '+' in varargs syntax |
| # (Not sure which alternative is better yet.) |
| |
| # 11-Jan-92: |
| # Variable length argument list syntax added: def f(a, b, +rest): ... |
| |
| # 8-Jan-92: |
| # Allow only '==' for equality testing |
| |
| # Changes since version 8: |
| # Trailing commas in formal parameter lists are allowed |
| |
| # Changes since version 7: |
| # New syntax to specify base classes (but old syntax retained for now) |
| # 'global' statement (valid only in functions but not enforced here) |
| |
| # Changes since version 6: |
| # Add logical operators '|', '^', '&' and '~' |
| # Add shift operators '<<' and '>>' |
| |
| # Changes since version 5: |
| # Comparison operators '<=' '>' '<>' are now 1 token |
| # Also support '!=' and '==' as alternatives for '<>' and '=' |
| |
| # Changes compared to version 4: |
| # Blank lines and lines only containing a comment are now eaten |
| # by the lexer, so the NEWLINE* things in suite are gone |
| # (but the 2nd NEWLINE terminating single_input stays!) |
| # Semicolons can separate small statements |
| # 'continue' statement |
| # Dictionary constructors: {key:value, key:value, ...} |
| # More tests instead of exprs |
| |
| # Changes compared to version 3: |
| # Removed 'dir' statement. |
| # Function call argument is a testlist instead of exprlist. |
| |
| # Changes compared to version 2: |
| # The syntax of Boolean operations is changed to use more |
| # conventional priorities: or < and < not. |
| |
| # Changes compared to version 1: |
| # modules and scripts are unified; |
| # 'quit' is gone (use ^D); |
| # empty_stmt is gone, replaced by explicit NEWLINE where appropriate; |
| # 'import' and 'def' aren't special any more; |
| # added 'from' NAME option on import clause, and '*' to import all; |
| # added class definition. |
| |
| # Start symbols for the grammar: |
| # single_input is a single interactive statement; |
| # file_input is a module or sequence of commands read from an input file; |
| # expr_input is the input for the input() function; |
| # eval_input is the input for the eval() function. |
| |
| # NB: compound_stmt in single_input is followed by extra NEWLINE! |
| single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE |
| file_input: (NEWLINE | stmt)* ENDMARKER |
| expr_input: testlist NEWLINE |
| eval_input: testlist NEWLINE* ENDMARKER |
| |
| funcdef: 'def' NAME parameters ':' suite |
| parameters: '(' [varargslist] ')' |
| varargslist: (fpdef ',')* '*' NAME | fpdef (',' fpdef)* [','] |
| fpdef: NAME | '(' fplist ')' |
| fplist: fpdef (',' fpdef)* [','] |
| |
| stmt: simple_stmt | compound_stmt |
| simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE |
| small_stmt: expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt | import_stmt | global_stmt |
| expr_stmt: (exprlist '=')* exprlist |
| # For assignments, additional restrictions enforced by the interpreter |
| print_stmt: 'print' (test ',')* [test] |
| del_stmt: 'del' exprlist |
| pass_stmt: 'pass' |
| flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt |
| break_stmt: 'break' |
| continue_stmt: 'continue' |
| return_stmt: 'return' [testlist] |
| raise_stmt: 'raise' test [',' test] |
| import_stmt: 'import' NAME (',' NAME)* | 'from' NAME 'import' ('*' | NAME (',' NAME)*) |
| global_stmt: 'global' NAME (',' NAME)* |
| compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | funcdef | classdef |
| if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite] |
| while_stmt: 'while' test ':' suite ['else' ':' suite] |
| for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite] |
| try_stmt: 'try' ':' suite (except_clause ':' suite)+ | 'try' ':' suite 'finally' ':' suite |
| # NB compile.c makes sure that the default except clause is last |
| except_clause: 'except' [test [',' test]] |
| suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT |
| |
| test: and_test ('or' and_test)* |
| and_test: not_test ('and' not_test)* |
| not_test: 'not' not_test | comparison |
| comparison: expr (comp_op expr)* |
| comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not' |
| expr: xor_expr ('|' xor_expr)* |
| xor_expr: and_expr ('^' and_expr)* |
| and_expr: shift_expr ('&' shift_expr)* |
| shift_expr: arith_expr (('<<'|'>>') arith_expr)* |
| arith_expr: term (('+'|'-') term)* |
| term: factor (('*'|'/'|'%') factor)* |
| factor: ('+'|'-'|'~') factor | atom trailer* |
| atom: '(' [testlist] ')' | '[' [testlist] ']' | '{' [dictmaker] '}' | '`' testlist '`' | NAME | NUMBER | STRING |
| trailer: '(' [testlist] ')' | '[' subscript ']' | '.' NAME |
| subscript: test | [test] ':' [test] |
| exprlist: expr (',' expr)* [','] |
| testlist: test (',' test)* [','] |
| dictmaker: test ':' test (',' test ':' test)* [','] |
| |
| # New class syntax should be: |
| # classdef: class NAME ['(' testlist ')'] ':' suite |
| # but merged with old syntax for compatibility it becomes: |
| classdef: 'class' NAME ['(' testlist ')' |'(' ')' ['=' baselist]] ':' suite |
| baselist: atom arguments (',' atom arguments)* |
| arguments: '(' ')' |