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|
# Grammar for Chapter 8
```antlrv4
grammar SimpleLanguage;
program
: statement+ EOF
;
statement
: returnStatement
| declStatement
| blockStatment
| expressionStatement
| ifStatement
| whileStatement
| metaStatement
;
whileStatement
: 'while' '(' expression ')' statement
;
ifStatement
: 'if' '(' expression ')' statement ('else' statement)?
;
metaStatement
: '#showGraph' ';'
;
expressionStatement
: IDENTIFIER '=' expression ';'
;
blockStatement
: '{' statement+ '}'
;
declStatement
: 'int' IDENTIFIER '=' expression ';'
;
returnStatement
: 'return' expression ';'
;
expression
: comparisonExpression
;
comparisonExpression
: additiveExpression (('==' | '!='| '>'| '<'| '>='| '<=') additiveExpression)*
;
additiveExpression
: multiplicativeExpression (('+' | '-') multiplicativeExpression)*
;
multiplicativeExpression
: unaryExpression (('*' | '/') unaryExpression)*
;
unaryExpression
: ('-') unaryExpression
| primaryExpression
;
primaryExpression
: IDENTIFIER
| INTEGER_LITERAL
| 'true'
| 'false'
| '(' expression ')'
;
INTEGER_LITERAL
: [1-9][0-9]*
| [0]
;
IDENTIFIER
: NON_DIGIT (NON_DIGIT | DIGIT)*
;
NON_DIGIT: [a-zA-Z_];
DEC_DIGIT: [0-9];
```
|
