SCAML/grammar.txt at master · Giodiro/SCAML · GitHub

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SCAML BNF

<program> ::= <top_level>
		| <program> <top_level>

<top_level> ::= <global def> | <expr>;;

<global def> ::= let <var> (<var1>:<type1> <varn>:<typen>):<type> = <expr>;; (n >= 0)
		| let <var>:<type> = <expr>;; 	Variable definition

<local def> ::= let <var> (<var1>:<type1> <varn>:<typen>):<type> = <expr> in <expr>
		| let <var>:<type> = <expr> in <expr> 	Variable definition

<expr> ::= <aexpr> Atomic expression
		| <local def>
		| <conditional>
		| (<expr> <list aexpr>) 		Function application

<aexpr> ::= (<expr>) Parenthesized expression
		| <var>
		| <set> 				Set or language
		| <int>
		| <string>
		| <built in> 			Built-in functions

<list aexpr> ::= <aexpr1> <aexpr2> <aexprn>		(n >= 0)

<conditional> ::= if <aexpr> then <aexpr> else <aexpr>

<var> ::= <alpha1><alpha2><alphan> (n >= 1) & (<var> must not be in <keyword>)

<word> ::= <alpha1><alpha2><alphan>

		| : 					Empty word

<set> ::= {<word1>, <wordn>} 	(n >= 0) & (all words are different)

<type> ::= int | string | set | bool

<built in> ::= cons | head | tail | == | + | - | strcomp | strapp

<keyword> ::= <built in>
		| if | then | else | let | in
		| <type>