Browsable Python INDENT/DEDENT Grammar

Grammar extracted by Vadim Zaytsev, see the Grammar Zoo entry for details: python/indentation/cordy/extracted
Source used for this grammar: James R. Cordy, Program to explicate standard Python INDENT/DEDENT symbols, November 2008

Summary

• Total 12 production rules with 23 top alternatives and 86 symbols.
• Vocabulary: 26 = 18 nonterminals + 8 terminals + 0 labels + 0 markers.
• Total 18 nonterminal symbols: 12 defined (program, line, endofline, indent, dedent, tab_space, linetoken, nonblank_token, compound, compoundtoken, compoundtokensquare, compoundtokenround), 1 root (program), 0 top (—), 6 bottom (newline ⁴, space, comment ⁴, SP ², token, tab).
• Total 8 terminal symbols: 2 keywords ("INDENT", "DEDENT"), 0 letters (—), 0 numerics (—), 6 signs ("{", "}", "[", "]", "(", ")").

Syntax

program ::=
	line*

line ::=
	tab_space* linetoken* indent? endofline+ dedent*

endofline ::=
	tab_space* comment? newline

indent ::=
	SP "INDENT"

dedent ::=
	"DEDENT" SP

tab_space ::=
	tab
	space

linetoken ::=
	tab_space
	nonblank_token

nonblank_token ::=
	compound
	token

compound ::=
	"{" compoundtoken* "}"
	"[" compoundtokensquare* "]"
	"(" compoundtokenround* ")"

compoundtoken ::=
	linetoken
	newline
	comment

compoundtokensquare ::=
	linetoken
	newline
	comment

compoundtokenround ::=
	linetoken
	newline
	comment

Maintained by Dr. Vadim Zaytsev a.k.a. @grammarware. Last updated in September 2015. [↑]