| Guido van Rossum | 85a5fbb | 1990-10-14 12:07:46 +0000 | [diff] [blame] | 1 | # Grammar for Python, version 3 |
| 2 | |
| 3 | # Changes compared to version 2: |
| 4 | # The syntax of Boolean operations is changed to use more |
| 5 | # conventional priorities: or < and < not. |
| 6 | |
| 7 | # Changes compared to version 1: |
| 8 | # modules and scripts are unified; |
| 9 | # 'quit' is gone (use ^D); |
| 10 | # empty_stmt is gone, replaced by explicit NEWLINE where appropriate; |
| 11 | # 'import' and 'def' aren't special any more; |
| 12 | # added 'from' NAME option on import clause, and '*' to import all; |
| 13 | # added class definition. |
| 14 | # TO DO: |
| 15 | # replace 'dir' by something more general? |
| 16 | |
| 17 | # Start symbols for the grammar: |
| 18 | # single_input is a single interactive statement; |
| 19 | # file_input is a module or sequence of commands read from an input file; |
| 20 | # expr_input is the input for the input() function; |
| 21 | # eval_input is the input for the eval() function. |
| 22 | |
| 23 | # NB: compound_stmt in single_input is followed by extra NEWLINE! |
| 24 | single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE |
| 25 | file_input: (NEWLINE | stmt)* ENDMARKER |
| 26 | expr_input: testlist NEWLINE |
| 27 | eval_input: testlist ENDMARKER |
| 28 | |
| 29 | funcdef: 'def' NAME parameters ':' suite |
| 30 | parameters: '(' [fplist] ')' |
| 31 | fplist: fpdef (',' fpdef)* |
| 32 | fpdef: NAME | '(' fplist ')' |
| 33 | |
| 34 | stmt: simple_stmt | compound_stmt |
| 35 | simple_stmt: expr_stmt | print_stmt | pass_stmt | del_stmt | dir_stmt | flow_stmt | import_stmt |
| 36 | expr_stmt: (exprlist '=')* exprlist NEWLINE |
| 37 | # For assignments, additional restrictions enforced by the interpreter |
| 38 | print_stmt: 'print' (test ',')* [test] NEWLINE |
| 39 | del_stmt: 'del' exprlist NEWLINE |
| 40 | dir_stmt: 'dir' [expr] NEWLINE |
| 41 | pass_stmt: 'pass' NEWLINE |
| 42 | flow_stmt: break_stmt | return_stmt | raise_stmt |
| 43 | break_stmt: 'break' NEWLINE |
| 44 | return_stmt: 'return' [testlist] NEWLINE |
| 45 | raise_stmt: 'raise' expr [',' expr] NEWLINE |
| 46 | import_stmt: 'import' NAME (',' NAME)* NEWLINE | 'from' NAME 'import' ('*' | NAME (',' NAME)*) NEWLINE |
| 47 | compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | funcdef | classdef |
| 48 | if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite] |
| 49 | while_stmt: 'while' test ':' suite ['else' ':' suite] |
| 50 | for_stmt: 'for' exprlist 'in' exprlist ':' suite ['else' ':' suite] |
| 51 | try_stmt: 'try' ':' suite (except_clause ':' suite)* ['finally' ':' suite] |
| 52 | except_clause: 'except' [expr [',' expr]] |
| 53 | suite: simple_stmt | NEWLINE INDENT NEWLINE* (stmt NEWLINE*)+ DEDENT |
| 54 | |
| 55 | test: and_test ('or' and_test)* |
| 56 | and_test: not_test ('and' not_test)* |
| 57 | not_test: 'not' not_test | comparison |
| 58 | comparison: expr (comp_op expr)* |
| 59 | comp_op: '<'|'>'|'='|'>' '='|'<' '='|'<' '>'|'in'|'not' 'in'|'is'|'is' 'not' |
| 60 | expr: term (('+'|'-') term)* |
| 61 | term: factor (('*'|'/'|'%') factor)* |
| 62 | factor: ('+'|'-') factor | atom trailer* |
| 63 | atom: '(' [testlist] ')' | '[' [testlist] ']' | '{' '}' | '`' testlist '`' | NAME | NUMBER | STRING |
| 64 | trailer: '(' [exprlist] ')' | '[' subscript ']' | '.' NAME |
| 65 | subscript: expr | [expr] ':' [expr] |
| 66 | exprlist: expr (',' expr)* [','] |
| 67 | testlist: test (',' test)* [','] |
| 68 | |
| 69 | classdef: 'class' NAME parameters ['=' baselist] ':' suite |
| 70 | baselist: atom arguments (',' atom arguments)* |
| 71 | arguments: '(' [testlist] ')' |