# Syntax (old)

### Top-level elements

```PEG
FunctionDeclaration ← FunctionSignature ';'
FunctionDefinition  ← FunctionSignature Block
FunctionSignature   ← Type identifier '(' SignatureArguments? ')'
SignatureArguments  ← Type identifier ',' SignatureArguments /
                      Type identifier ','?
```

### Statements

```PEG
Block                   ← '{' Statement* '}'
    
Statement               ← VariableDefinition /
                          VariableDeclaration /
                          IfStatement /
                          SwitchStatement /
                          WhileStatement /
                          DoWhileStatement /
                          ForStatement /
                          FlowControlStatement /
                          AssignmentStatement /
                          ExpressionStatement
    
VariableDefinition      ← Type identifier '=' Expression ';'
VariableDeclaration     ← Type identifier ';'
    
IfStatement             ← 'if' Expression Block 'else' Block /
                          'if' Expression Block
    
SwitchStatement         ← 'switch' Expression '{' SwitchCase+ '}'
SwitchCase              ← CaseSpecifier Block /
                          'default' Block
CaseSpecifier           ← 'case' Expression ',' CaseSpecifier /
                          'case' Expression ','?
    
WhileStatement          ← 'while' Expression Block
DoWhileStatement        ← 'do' Block 'while' Expression ';'
ForStatement            ← 'for' VariableDefinition? ';' Expression ';' AssignmentStatementBody? Block

FlowControlStatement    ← 'continue' ';' /
                          'break' ';' /
                          'return' Expression? ';'

AssignmentStatement     ← AssignmentStatementBody ';'
AssignmentStatementBody ← AssignmentTargetExpression '=' Expression /
                          AssignmentTargetExpression '+=' Expression /
                          AssignmentTargetExpression '-=' Expression /
                          AssignmentTargetExpression '*=' Expression /
                          AssignmentTargetExpression '/=' Expression /
                          AssignmentTargetExpression '%=' Expression /
                          AssignmentTargetExpression '&=' Expression /
                          AssignmentTargetExpression '^=' Expression /
                          AssignmentTargetExpression '|=' Expression /
                          AssignmentTargetExpression '++' /
                          AssignmentTargetExpression '--'

ExpressionStatement     ← Expression ';'
```

### Types

```PEG
Type        ← 'const' BasicType /
              BasicType '*' /
              BasicType '[' Expression ']' /
              BasicType 'function' '(' (BasicType ',')* ')' /
              BasicType
BasicType   ← 'void' /
              IntegerType /
              'signed' IntegerType /
              'unsigned' IntegerType /
              'float' /
              'double' /
              'bool' /
              'struct' identifier /
              'enum' identifier /
              'typedef' identifier /
              '(' Type ')'
IntegerType ← 'char' /
              'short' /
              'int' /
              'long'
```

### Expressions

```PEG
AssignmentTargetExpression ← identifier ATEElementSuffix*
ATEElementSuffix           ← '[' Expression ']' /
                             '.' identifier /
                             '->' identifier

AtomicExpression           ← identifier /
                             constant /
                             string-literal /
                             '(' Expression ')'

ObjectExpression           ← AtomicExpression ObjectSuffix* /
                             ArrayLiteralExpression /
                             StructLiteralExpression
ObjectSuffix               ← '[' Expression ']' /
                             '(' CommasExpressionList? ')' /
                             '.' identifier /
                             '->' identifier
CommasExpressionList       ← Expression ',' CommasExpressionList? /
                             Expression ','?
ArrayLiteralExpression     ← '{' CommasExpressionList '}'
StructLiteralExpression    ← '{' StructLiteralBody '}'
StructLiteralBody          ← StructLiteralElement ',' StructLiteralBody? /
                             StructLiteralElement ','?
StructLiteralElement       ← '.' identifier '=' Expression

FactorExpression           ← '(' Type ')' FactorExpression /
                             '&' FactorExpression /
                             '*' FactorExpression /
                             '+' FactorExpression /
                             '-' FactorExpression /
                             '~' FactorExpression /
                             '!' FactorExpression /
                             'sizeof' FactorExpression /
                             'sizeof' Type /
                             ObjectExpression

TermExpression             ← FactorExpression TermSuffix*
TermSuffix                 ← '*' FactorExpression /
                             '/' FactorExpression /
                             '%' FactorExpression

ArithmeticExpression       ← TermExpression ArithmeticSuffix*
ArithmeticSuffix           ← '+' TermExpression /
                             '-' TermExpression

BitwiseOpExpression        ← ArithmeticExpression '<<' ArithmeticExpression /
                             ArithmeticExpression '>>' ArithmeticExpression /
                             ArithmeticExpression '^' ArithmeticExpression /
                             ArithmeticExpression ('&' ArithmeticExpression)+ /
                             ArithmeticExpression ('|' ArithmeticExpression)+ /
                             ArithmeticExpression

ComparisonExpression       ← BitwiseOpExpression '==' BitwiseOpExpression /
                             BitwiseOpExpression '!=' BitwiseOpExpression /
                             BitwiseOpExpression '<=' BitwiseOpExpression /
                             BitwiseOpExpression '>=' BitwiseOpExpression /
                             BitwiseOpExpression '<' BitwiseOpExpression /
                             BitwiseOpExpression '>' BitwiseOpExpression /
                             BitwiseOpExpression

Expression                 ← ComparisonExpression ('&&' ComparisonExpression)+ /
                             ComparisonExpression ('||' ComparisonExpression)+ /
                             ComparisonExpression
```