Return Styles: Pseud0ch, Terminal, Valhalla, NES, Geocities, Blue Moon.

Pages: 1-

python has an impressively concise grammar

Name: Anonymous 2012-02-09 18:37

single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
file_input: (NEWLINE | stmt)* ENDMARKER
eval_input: testlist NEWLINE* ENDMARKER

decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
decorators: decorator+
decorated: decorators (classdef | funcdef)
funcdef: 'def' NAME parameters ['->' test] ':' suite
parameters: '(' [typedargslist] ')'
typedargslist: ((tfpdef ['=' test] ',')*
                ('*' [tfpdef] (',' tfpdef ['=' test])* [',' '**' tfpdef] | '**' tfpdef)
                | tfpdef ['=' test] (',' tfpdef ['=' test])* [','])
tfpdef: NAME [':' test]
varargslist: ((vfpdef ['=' test] ',')*
              ('*' [vfpdef] (',' vfpdef ['=' test])*  [',' '**' vfpdef] | '**' vfpdef)
              | vfpdef ['=' test] (',' vfpdef ['=' test])* [','])
vfpdef: NAME

stmt: simple_stmt | compound_stmt
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
small_stmt: (expr_stmt | del_stmt | pass_stmt | flow_stmt |
             import_stmt | global_stmt | nonlocal_stmt | assert_stmt)
expr_stmt: testlist (augassign (yield_expr|testlist) |
                     ('=' (yield_expr|testlist))*)
augassign: ('+=' | '-=' | '*=' | '/=' | '%=' | '&=' | '|=' | '^=' |
            '<<=' | '>>=' | '**=' | '//=')
# For normal assignments, additional restrictions enforced by the interpreter
del_stmt: 'del' exprlist
pass_stmt: 'pass'
flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt | yield_stmt
break_stmt: 'break'
continue_stmt: 'continue'
return_stmt: 'return' [testlist]
yield_stmt: yield_expr
raise_stmt: 'raise' [test ['from' test]]
import_stmt: import_name | import_from
import_name: 'import' dotted_as_names
# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
import_from: ('from' (('.' | '...')* dotted_name | ('.' | '...')+)
              'import' ('*' | '(' import_as_names ')' | import_as_names))
import_as_name: NAME ['as' NAME]
dotted_as_name: dotted_name ['as' NAME]
import_as_names: import_as_name (',' import_as_name)* [',']
dotted_as_names: dotted_as_name (',' dotted_as_name)*
dotted_name: NAME ('.' NAME)*
global_stmt: 'global' NAME (',' NAME)*
nonlocal_stmt: 'nonlocal' NAME (',' NAME)*
assert_stmt: 'assert' test [',' test]

compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | with_stmt | funcdef | classdef | decorated
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)+
        ['else' ':' suite]
        ['finally' ':' suite] |
       'finally' ':' suite))
with_stmt: 'with' with_item (',' with_item)*  ':' suite
with_item: test ['as' expr]
# NB compile.c makes sure that the default except clause is last
except_clause: 'except' [test ['as' NAME]]
suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT

test: or_test ['if' or_test 'else' test] | lambdef
test_nocond: or_test | lambdef_nocond
lambdef: 'lambda' [varargslist] ':' test
lambdef_nocond: 'lambda' [varargslist] ':' test_nocond
or_test: and_test ('or' and_test)*
and_test: not_test ('and' not_test)*
not_test: 'not' not_test | comparison
comparison: star_expr (comp_op star_expr)*
comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
star_expr: ['*'] expr
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 | power
power: atom trailer* ['**' factor]
atom: ('(' [yield_expr|testlist_comp] ')' |
       '[' [testlist_comp] ']' |
       '{' [dictorsetmaker] '}' |
       NAME | NUMBER | STRING+ | '...' | 'None' | 'True' | 'False')
testlist_comp: test ( comp_for | (',' test)* [','] )
trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
subscriptlist: subscript (',' subscript)* [',']
subscript: test | [test] ':' [test] [sliceop]
sliceop: ':' [test]
exprlist: star_expr (',' star_expr)* [',']
testlist: test (',' test)* [',']
dictorsetmaker: ( (test ':' test (comp_for | (',' test ':' test)* [','])) |
                  (test (comp_for | (',' test)* [','])) )

classdef: 'class' NAME ['(' [arglist] ')'] ':' suite

arglist: (argument ',')* (argument [',']
                         |'*' test (',' argument)* [',' '**' test]
                         |'**' test)
# The reason that keywords are test nodes instead of NAME is that using NAME
# results in an ambiguity. ast.c makes sure it's a NAME.
argument: test [comp_for] | test '=' test  # Really [keyword '='] test
comp_iter: comp_for | comp_if
comp_for: 'for' exprlist 'in' or_test [comp_iter]
comp_if: 'if' test_nocond [comp_iter]

testlist1: test (',' test)*

# not used in grammar, but may appear in "node" passed from Parser to Compiler
encoding_decl: NAME

yield_expr: 'yield' [testlist]


no wonder people say it has the cleanest syntax of any language!

Name: Anonymous 2012-02-09 20:31

Javascript's is better.

Name: Anonymous 2012-02-09 22:42

I see decorators there.

[b][i]THE FORCED INDENTATION OF ENTERPRISE CODE[/b][/i]

Name: Anonymous 2012-02-10 3:45

concise compared to what, lisp?

Name: Anonymous 2012-02-10 8:52

FreeBasic has the cleanest syntax.

Name: Anonymous 2012-02-10 8:57

Python is bloated but Lisp is shit.

Name: Anonymous 2012-02-10 10:39

Compare to Lua:

chunk ::= {stat [`;´]} [laststat [`;´]]

    block ::= chunk

    stat ::=  varlist `=´ explist |
         functioncall |
         do block end |
         while exp do block end |
         repeat block until exp |
         if exp then block {elseif exp then block} [else block] end |
         for Name `=´ exp `,´ exp [`,´ exp] do block end |
         for namelist in explist do block end |
         function funcname funcbody |
         local function Name funcbody |
         local namelist [`=´ explist]

    laststat ::= return [explist] | break

    funcname ::= Name {`.´ Name} [`:´ Name]

    varlist ::= var {`,´ var}

    var ::=  Name | prefixexp `[´ exp `]´ | prefixexp `.´ Name

    namelist ::= Name {`,´ Name}

    explist ::= {exp `,´} exp

    exp ::=  nil | false | true | Number | String | `...´ | function |
         prefixexp | tableconstructor | exp binop exp | unop exp

    prefixexp ::= var | functioncall | `(´ exp `)´

    functioncall ::=  prefixexp args | prefixexp `:´ Name args

    args ::=  `(´ [explist] `)´ | tableconstructor | String

    function ::= function funcbody

    funcbody ::= `(´ [parlist] `)´ block end

    parlist ::= namelist [`,´ `...´] | `...´

    tableconstructor ::= `{´ [fieldlist] `}´

    fieldlist ::= field {fieldsep field} [fieldsep]

    field ::= `[´ exp `]´ `=´ exp | Name `=´ exp | exp

    fieldsep ::= `,´ | `;´

    binop ::= `+´ | `-´ | `*´ | `/´ | `^´ | `%´ | `..´ |
         `<´ | `<=´ | `>´ | `>=´ | `==´ | `~=´ |
         and | or

    unop ::= `-´ | not | `#´

Name: Anonymous 2012-02-10 12:33

>>4
You're not very smart, are you?

Name: Anonymous 2012-02-10 14:09

C++11 is better.

Name: Anonymous 2012-03-12 6:04

>>11
nice dubs bro

Name: Anonymous 2012-03-12 6:04

Impressively concise dubs

Name: Anonymous 2012-03-12 12:35

>>11
bro... you should have said

C++11 DUBS, CHECK UM

Don't change these.
Name: Email:
Entire Thread Thread List