solidity/libsolidity/grammar.txt

ContractDefinition = ( 'contract' | 'library' ) Identifier
                     ( 'is' InheritanceSpecifier (',' InheritanceSpecifier )* )?
                     '{' ContractPart* '}'
ContractPart = StateVariableDeclaration | StructDefinition | ModifierDefinition | FunctionDefinition | EnumDefinition

InheritanceSpecifier = Identifier ( '(' Expression ( ',' Expression )* ')' )?
StructDefinition = 'struct' Identifier '{'
                     ( VariableDeclaration (';' VariableDeclaration)* )? '}'
StateVariableDeclaration = TypeName ( 'public' | 'internal' | 'private' )? Identifier ';'
ModifierDefinition = 'modifier' Identifier ParameterList? Block
FunctionDefinition = 'function' Identifier ParameterList
                     ( Identifier | 'constant' | 'external' | 'public' | 'internal' | 'private' )*
                     ( 'returns' ParameterList )? Block

EnumValue = Identifier
EnumDefinition = 'enum' Identifier '{' EnumValue? (',' EnumValue)* '}'
ParameterList = '(' ( VariableDeclaration (',' VariableDeclaration)* )? ')'
// semantic restriction: mappings and structs (recursively) containing mappings
// are not allowed in argument lists
VariableDeclaration = TypeName Identifier
TypeName = ElementaryTypeName | Identifier | Mapping | ArrayTypeName
Mapping = 'mapping' '(' ElementaryTypeName '=>' TypeName ')'
ArrayTypeName = TypeName '[' Expression? ']'

Block = '{' Statement* '}'
Statement = IfStatement | WhileStatement | ForStatement | Block |
            ( Continue | Break | Return | Throw | VariableDefinition | ExpressionStatement ) ';'

ExpressionStatement = Expression
IfStatement = 'if' '(' Expression ')' Statement ( 'else' Statement )?
WhileStatement = 'while' '(' Expression ')' Statement
VardefOrExprStmt = Variabledefinition | ExpressionStatement
ForStatement = 'for' '(' (VardefOrExprStmt)? ';' (Expression)? ';' (ExpressionStatement)? ')' Statement
Continue = 'continue'
Break = 'break'
Return = 'return' Expression?
Throw = 'throw'
VariableDefinition = VariableDeclaration ( '=' Expression )?

Expression = Assignment | UnaryOperation | BinaryOperation | FunctionCall | NewExpression | IndexAccess |
             MemberAccess | PrimaryExpression
// The expression syntax is actually much more complicated
Assignment = Expression (AssignmentOp Expression)
AssignmentOp = '|=' | '^=' | '&=' | '<<=' | '>>=' | '+=' | '-=' | '*=' | '/=' | '%='
UnaryOperation = '!' | '~' | '++' | '--' | 'delete'
BinaryOperation = '|' | '^' | '&' | '<<' | '>>' | '+' | '-' | '*' | '/' | '%'
                  | '||' | '&&' | '**' | '==' | '!=' | '<' | '>' | '<=' | '>='

FunctionCall = Identifier '(' Expression? ( ',' Expression )* ')'
NewExpression = 'new' Identifier
MemberAccess = Expression '.' Identifier
IndexAccess = Identifier ('[' Expression? ']')+
PrimaryExpression = Identifier | NumberLiteral | StringLiteral | ElementaryTypeName | '(' Expression ')'