Parsing Expression With Xtext
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The document describes the step-by-step parsing of the mathematical expression "(1 + 20) * 2" according to a specified grammar. The parsing breaks the expression down into a stack of syntactic elements including number literals, additions, multiplications, and primaries according to the grammar rules.
Parsing Expression With Xtext
- 1. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition StackAST Grammar Text
- 2. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text
- 3. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text
- 4. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text
- 5. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text
- 6. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text
- 7. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication StackAST Grammar Text
- 8. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication 6.PrimaryExpression StackAST Grammar Text
- 9. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication 6.PrimaryExpression StackAST Grammar Text
- 10. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication 6.PrimaryExpression StackAST Grammar Text 1
- 11. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication 6.PrimaryExpression StackAST Grammar Text 1
- 12. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication StackAST Grammar Text 1 Reduce!
- 13. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1 Reduce!
- 14. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1
- 15. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1 +
- 16. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1 + current = ruleMultiplication(); // {AdditionalExpression.left=current} AdditionalExpression temp = new AdditionalExpression(); temp.setLeft(current); current = temp:
- 17. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1 +
- 18. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1 +
- 19. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1 +
- 20. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication StackAST Grammar Text 1 +
- 21. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition 5.Multiplication 6.PrimaryExpression StackAST Grammar Text 1 +
- 22. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression 4.Addition StackAST Grammar Text 1 + 20 Reduce!
- 23. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text 1 + 20 Reduce!
- 24. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text 1 + 20
- 25. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text 1 + 20
- 26. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text 1 + 20 Reduce!
- 27. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text 1 + 20 *
- 28. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text 1 + 20 *
- 29. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text 1 + 20 *
- 30. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text 1 + 20 *
- 31. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text 1 + 20 * 2
- 32. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication 3.PrimaryExpression StackAST Grammar Text 1 + 20 * EOF 2
- 33. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text 1 + 20 * EOF Reduce! 2
- 34. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition 2.Multiplication StackAST Grammar Text 1 + 20 * EOF 2
- 35. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 1.Addition StackAST Grammar Text 1 + 20 * EOF 2 Reduce!
- 36. Addition returns Expression: Multiplication ({AdditionalExpression.left=current} '+' right=Multiplication)*; Multiplication returns Expression: PrimaryExpression ({MultiplyExpression.left=current} '*' right=PrimaryExpression)*; PrimaryExpression returns Expression: {NumberLiteral} value=INT | '(' Addition ')'; ( 1 + 20 ) * 2 StackAST Grammar Text 1 + 20 * EOF 2 Finished!