Browsable Pico Grammar

Grammar extracted by Vadim Zaytsev, see the Grammar Zoo entry for details: toy/pico/unknown/sdf/extracted
Source used for this grammar: Jurgen Vinju, Pico.sdf, Identifiers.sdf, Types.sdf, February 2006 – September 2007

Summary

• Total 16 production rules with 16 top alternatives and 115 symbols.
• Vocabulary: 31 = 9 nonterminals + 22 terminals + 0 labels + 0 markers.
• Total 9 nonterminal symbols: 6 defined (PROGRAM, DECLS, ID-TYPE, STATEMENT, EXP, TYPE), 0 root (—), 1 top (PROGRAM), 3 bottom (StrCon, PICO-ID ³, NatCon).
• Total 22 terminal symbols: 12 keywords ("begin", "end", "declare", "if", "then", "else", "fi", "while", "do", "od", "natural", "string"), 0 letters (—), 0 numerics (—), 9 signs (";" ⁵, ",", ":", ":=", "+", "-", "||", "(", ")").

Syntax

PROGRAM ::=
	"begin" DECLS (STATEMENT (";" STATEMENT)*)? "end"

DECLS ::=
	"declare" (ID-TYPE ("," ID-TYPE)*)? ";"

ID-TYPE ::=
	PICO-ID ":" TYPE

STATEMENT ::=
	PICO-ID ":=" EXP

STATEMENT ::=
	"if" EXP "then" (STATEMENT (";" STATEMENT)*)? "else" (STATEMENT (";" STATEMENT)*)? "fi"

STATEMENT ::=
	"while" EXP "do" (STATEMENT (";" STATEMENT)*)? "od"

EXP ::=
	PICO-ID

EXP ::=
	NatCon

EXP ::=
	StrCon

EXP ::=
	EXP "+" EXP

EXP ::=
	EXP "-" EXP

EXP ::=
	EXP "||" EXP

EXP ::=
	"(" EXP ")"

TYPE ::=
	"natural"

TYPE ::=
	"string"

TYPE ::=
	"nil-type"

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