82 lines
3.4 KiB
Plaintext
82 lines
3.4 KiB
Plaintext
# Grammar for Python
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# Commands for Kees Blom's railroad program
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#diagram:token NAME
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#diagram:token NUMBER
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#diagram:token STRING
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#diagram:token NEWLINE
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#diagram:token ENDMARKER
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#diagram:token INDENT
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#diagram:output\input python.bla
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#diagram:token DEDENT
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#diagram:output\textwidth 20.04cm\oddsidemargin 0.0cm\evensidemargin 0.0cm
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#diagram:rules
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# Start symbols for the grammar:
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# single_input is a single interactive statement;
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# file_input is a module or sequence of commands read from an input file;
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# eval_input is the input for the eval() and input() functions.
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# NB: compound_stmt in single_input is followed by extra NEWLINE!
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single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
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file_input: (NEWLINE | stmt)* ENDMARKER
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eval_input: testlist NEWLINE* ENDMARKER
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funcdef: 'def' NAME parameters ':' suite
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parameters: '(' [varargslist] ')'
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varargslist: (fpdef ['=' test] ',')* '*' NAME | fpdef ['=' test] (',' fpdef ['=' test])* [',']
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fpdef: NAME | '(' fplist ')'
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fplist: fpdef (',' fpdef)* [',']
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stmt: simple_stmt | compound_stmt
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simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
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small_stmt: expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt | import_stmt | global_stmt | access_stmt | exec_stmt
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expr_stmt: testlist ('=' testlist)*
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# For assignments, additional restrictions enforced by the interpreter
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print_stmt: 'print' (test ',')* [test]
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del_stmt: 'del' exprlist
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pass_stmt: 'pass'
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flow_stmt: break_stmt | continue_stmt | return_stmt | raise_stmt
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break_stmt: 'break'
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continue_stmt: 'continue'
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return_stmt: 'return' [testlist]
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raise_stmt: 'raise' test [',' test]
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import_stmt: 'import' NAME (',' NAME)* | 'from' NAME 'import' ('*' | NAME (',' NAME)*)
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global_stmt: 'global' NAME (',' NAME)*
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access_stmt: 'access' ('*' | NAME (',' NAME)*) ':' accesstype (',' accesstype)*
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accesstype: NAME+
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# accesstype should be ('public' | 'protected' | 'private') ['read'] ['write']
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# but can't be because that would create undesirable reserved words!
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exec_stmt: 'exec' expr ['in' test [',' test]]
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compound_stmt: if_stmt | while_stmt | for_stmt | try_stmt | funcdef | classdef
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if_stmt: 'if' test ':' suite ('elif' test ':' suite)* ['else' ':' suite]
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while_stmt: 'while' test ':' suite ['else' ':' suite]
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for_stmt: 'for' exprlist 'in' testlist ':' suite ['else' ':' suite]
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try_stmt: ('try' ':' suite (except_clause ':' suite)+ #diagram:break
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['else' ':' suite] | 'try' ':' suite 'finally' ':' suite)
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# NB compile.c makes sure that the default except clause is last
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except_clause: 'except' [test [',' test]]
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suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT
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test: and_test ('or' and_test)* | lambdef
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and_test: not_test ('and' not_test)*
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not_test: 'not' not_test | comparison
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comparison: expr (comp_op expr)*
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comp_op: '<'|'>'|'=='|'>='|'<='|'<>'|'!='|'in'|'not' 'in'|'is'|'is' 'not'
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expr: xor_expr ('|' xor_expr)*
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xor_expr: and_expr ('^' and_expr)*
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and_expr: shift_expr ('&' shift_expr)*
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shift_expr: arith_expr (('<<'|'>>') arith_expr)*
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arith_expr: term (('+'|'-') term)*
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term: factor (('*'|'/'|'%') factor)*
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factor: ('+'|'-'|'~') factor | atom trailer*
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atom: '(' [testlist] ')' | '[' [testlist] ']' | '{' [dictmaker] '}' | '`' testlist '`' | NAME | NUMBER | STRING+
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lambdef: 'lambda' [varargslist] ':' test
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trailer: '(' [testlist] ')' | '[' subscript ']' | '.' NAME
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subscript: test | [test] ':' [test]
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exprlist: expr (',' expr)* [',']
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testlist: test (',' test)* [',']
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dictmaker: test ':' test (',' test ':' test)* [',']
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classdef: 'class' NAME ['(' testlist ')'] ':' suite
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