Browsable Pico Grammar

Grammar connected by Vadim Zaytsev, see the Grammar Zoo entry for details: toy/pico/unknown/rascal/connected
Source used for this grammar: Jurgen Vinju, lang::pico::syntax::Main, 2011–2012 [Explore]

Summary

• Total 9 production rules with 20 top alternatives and 137 symbols.
• Vocabulary: 61 = 9 nonterminals + 23 terminals + 14 labels + 15 markers.
• Total 9 nonterminal symbols: 9 defined (Type, Statement, Program, Declarations, Expression, IdType, Id, String, Natural), 1 root (Program), 0 top (—), 0 bottom (—).
• Total 23 terminal symbols: 12 keywords ("natural", "string", "if" ², "then" ², "else", "fi" ², "while", "do", "od", "begin", "end", "declare"), 0 letters (—), 0 numerics (—), 10 signs (":=", ";" ⁶, ",", "(", ")", "||", "-", "+", ":", """ ²).
• Total 14 labels: [natural], [nil], [string], [assign], [cond] ², [loop], [program], [strcon], [id], [natcon], [concat], [min], [add], [idtype].
• Total 15 markers: ⟨var⟩, ⟨val⟩, ⟨cond⟩ ³, ⟨thenPart⟩ ², ⟨elsePart⟩, ⟨body⟩ ², ⟨decls⟩ ², ⟨string⟩, ⟨name⟩, ⟨natcon⟩, ⟨e⟩, ⟨lhs⟩ ³, ⟨rhs⟩ ³, ⟨id⟩, ⟨t⟩.

Syntax

Type ::=
	[natural]::"natural"
	[nil]::"nil-type"
	[string]::"string"

Statement ::=
	[assign]::(⟨var⟩:Id ":=" ⟨val⟩:Expression)
	[cond]::("if" ⟨cond⟩:Expression "then" ⟨thenPart⟩:{Statement ";"}* "else" ⟨elsePart⟩:{Statement ";"}* "fi")
	[loop]::("while" ⟨cond⟩:Expression "do" ⟨body⟩:{Statement ";"}* "od")
	[cond]::("if" ⟨cond⟩:Expression "then" ⟨thenPart⟩:{Statement ";"}* "fi")

Program ::=
	[program]::("begin" ⟨decls⟩:Declarations ⟨body⟩:{Statement ";"}* "end")

Declarations ::=
	"declare" ⟨decls⟩:{IdType ","}* ";"

Expression ::=
	[strcon]::⟨string⟩:String
	[id]::⟨name⟩:Id
	[natcon]::⟨natcon⟩:Natural
	"(" ⟨e⟩:Expression ")"
	[concat]::(⟨lhs⟩:Expression "||" ⟨rhs⟩:Expression)
	[min]::(⟨lhs⟩:Expression "-" ⟨rhs⟩:Expression)
	[add]::(⟨lhs⟩:Expression "+" ⟨rhs⟩:Expression)

IdType ::=
	[idtype]::(⟨id⟩:Id ":" ⟨t⟩:Type)

Id ::=
	string

String ::=
	""" string """

Natural ::=
	integer

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