grammar Ox

entry OxProgram:

elements+=OxElement*;

OxElement:

Block |

IfStatement |

WhileStatement |

ForStatement |

FunctionDeclaration |

VariableDeclaration ';' |

AssignmentStatement ';' |

PrintStatement ';' |

ReturnStatement ';' |

Expression ';'

IfStatement:

'if' '(' condition=Expression ')' block=Block

('else' elseBlock=Block)?

WhileStatement:

'while' '(' condition=Expression ')' block=Block

ForStatement:

'for' '(' counter=VariableDeclaration? ';' condition=Expression? ';' execution=AssignmentStatement? ')' block=Block

PrintStatement: 'print' value=Expression;

ReturnStatement: 'return' value=Expression?;

Block: '{'

elements+=OxElement*

VariableDeclaration returns NamedElement:

{infer VariableDeclaration} 'var' name=ID (':' type=TypeReference) (assignment?='=' value=Expression)?

AssignmentStatement:

varRef=[VariableDeclaration:ID] '=' value=Expression

Expression:

Addition;

Addition infers Expression:

Multiplication ({infer BinaryExpression.left=current} operator=('+' | '-') right=Multiplication)*;

Multiplication infers Expression:

Logical ({infer BinaryExpression.left=current} operator=('*' | '/') right=Logical)*;

Logical infers Expression:

Comparison ({infer BinaryExpression.left=current} operator=('and' | 'or') right=Comparison)*;

Comparison infers Expression:

Primary ({infer BinaryExpression.left=current} operator=('<' | '<=' | '>' | '>=' | '==' | '!=') right=Primary)*;

Primary infers Expression:

'(' Expression ')' |

UnaryExpression |

BooleanExpression |

NumberExpression |

MemberCall;

MemberCall:

element=[NamedElement:ID] (

explicitOperationCall?='('

(

arguments+=Expression (',' arguments+=Expression)*

)?

')')?;

UnaryExpression:

operator=('!' | '-') value=Expression

NumberExpression: value=NUMBER;

BooleanExpression: value?='true' | 'false';

FunctionDeclaration:

'fun' name=ID '(' (parameters+=Parameter (',' parameters+=Parameter)*)? ')' ':' returnType=TypeReference body=Block;

Parameter: name=ID ':' type=TypeReference;

TypeReference: primitive=("number" | "boolean" | "void");

type NamedElement = Parameter | FunctionDeclaration | VariableDeclaration;

hidden terminal WS: /\s+/;

terminal ID: /[_a-zA-Z][\w_]*/;

terminal NUMBER returns number: /[0-9]+(\.[0-9]+)?/;

hidden terminal ML_COMMENT: /\/\*[\s\S]*?\*\//;

hidden terminal SL_COMMENT: /\/\/[^\n\r]*/;