Appendix A MAL syntax summary

The MAL syntax is summarized below in extended BNF. Alternative constructs are seperated by | and grouped by parenthesis. Optional parts are marked with square brackets. A repetition is marked with either '+' or '*' to indicate at least once and many times, respectively. Lexical tokens are illustrated in small capitals.

program	: (statement ';') *
statement	: moduleStmt [helpinfo] | definition [helpinfo]
	| includeStmt | stmt
moduleStmt	: module ident | atom ident [':'ident]
includeStmt	: include identifier | include string_literal
definition	: command header address identifier
	| pattern header address identifier
	| function header statement* end identifier
	| factory header statement* end identifier
helpinfo	: comment string_literal
header	: [ moduelName '.'] name '(' params ')' result
result	: paramType | '(' params ')'
params	: binding [',' binding]*
binding	: identifier typeName [ props ]
typeName	: scalarType | collectionType | ':' any ['_' digit]
scalarType	: ':' identifier
collectionType	: ':' bat ['[' colType ',' colType ']']
colType	: scalarType | anyType
props	: '{' property [ ',' property]* '}'
property	: identifier [ compare literal]
compare	: '=' | '<' | '<=' | '>' | '>=' | '!='
stmt	: [tag] varlist [':=' expr ]
tag	| return | barrier | catch | leave | redo | raise
varlist	: variable | '(' variable [',' variable ] * ')'
variable	: identifier [ props ]
expr	: fcncall | [factor operator] factor
factor	: literal_constant | nil | var
fcncall	: moduleName '.' name '(' [args] ')'
args	: factor [',' factor]*