jgs Compilers Lecture 15: Syntactic Errors Dr. Javier Gonzalez-Sanchez [email protected] 

jgs Second Project Our Language 

Dr. Javier Gonzalez-Sanchez | Compilers | 3 jgs KEYWORD {class, return, print} STRING Language Actions Expressions (operators) Instructions Control Structures ARITHMETIC OPERATORS { +, -, *, /, =} LOGIC OPERATORS { &, |, ! } RELATIONAL OPERATORS {<, >, ==, !=, <=, >=} KEYWORD { if, else, do, while, for, switch, case } Data INTEGER FLOAT HEXADECIMAL CHAR KEYWORD { void, int, char, string, float, boolean } KEYWORD { true, false } BINARY Delimiter : ; , ( ) { } [ ] Our Language OCTAL IDENTIFIER 

Dr. Javier Gonzalez-Sanchez | Compilers | 4 jgs Our Grammar 1. PROGRAM 

Dr. Javier Gonzalez-Sanchez | Compilers | 5 jgs Our Grammar 2. METHODS 3. BODY 

Dr. Javier Gonzalez-Sanchez | Compilers | 6 jgs Our Grammar 4. TYPE Add spanish! 

Dr. Javier Gonzalez-Sanchez | Compilers | 7 jgs Our Grammar 5. PARAMS 6. ASSIGNMENT 7. EXPRESSION 

Dr. Javier Gonzalez-Sanchez | Compilers | 8 jgs Our Grammar 9. Y 10. R 8. X What about >= or <= ? 

Dr. Javier Gonzalez-Sanchez | Compilers | 9 jgs Our Grammar 12. A 13. B 11. E 

Dr. Javier Gonzalez-Sanchez | Compilers | 10 jgs Our Grammar 14. C What about call a method and use the returned value? 

Dr. Javier Gonzalez-Sanchez | Compilers | 11 jgs Our Grammar 15. VARIABLE 16. WHILE 17. IF 

Dr. Javier Gonzalez-Sanchez | Compilers | 12 jgs Our Grammar 19, CALL_METHOD 20. PARAM_VALUES 18. RETURN 

Dr. Javier Gonzalez-Sanchez | Compilers | 13 jgs Our Grammar 22. FOR 23. SWITCH 21. DOWHILE 

jgs Test Yourselves 

Dr. Javier Gonzalez-Sanchez | Compilers | 15 jgs Our Grammar throw new RuntimeException("Expected …"); 

Dr. Javier Gonzalez-Sanchez | Compilers | 16 jgs Assignment 2 | Input Are there syntactical errors? class Test1{ int x; float x; string x; char x; void x; boolean x; } 

Dr. Javier Gonzalez-Sanchez | Compilers | 17 jgs Assignment 2 | Input Are there syntactical errors? class Test2{ void metodo() { int x; x = 5; x = 05; x = 0x5ff; x = 5.55; x = "five"; x = '5'; x = false; } } 

Dr. Javier Gonzalez-Sanchez | Compilers | 18 jgs Assignment 2 | Input Are there syntactical errors? class Test3 { void metodo() { x = "hello" + "world" – 'w' * 5 / 3.4; x = y – hello & 0xffff | 05; x = -7; x = !y; x = (cse340 + cse310) / cse101 ; x = false + x + x + x + x / x > x && x==5; } } 

Dr. Javier Gonzalez-Sanchez | Compilers | 19 jgs Assignment 2 | Input Are there syntactical errors? class Test4 { void metodo() { x = 0; int x; y = 1 + 1; x = (0b11) +(05 – 0xFF34); while (2 == "hi") { a = 2 > (4 + Y); if (true) { if( 2 + 2 ) {} else {} } } print ("hello" + "world"); } } 

Dr. Javier Gonzalez-Sanchez | Compilers | 20 jgs Assignment 2 | Input Are there syntactical errors? class Test5 { void metodo() { x = 0; int x; y = 1 + 1; x = (0b11) +(05 – 0xFF34); while (2 == "hi") a = 2 > (4 + Y); if (true) { if( 2 + 2 ) {} else {} } print ("hello" + "world"); } } 

Dr. Javier Gonzalez-Sanchez | Compilers | 21 jgs Assignment 2 | Input Are there syntactical errors? class Test6 { void metodo() { if ( if ( if (x – 3) {} ) ) { print ("hello" + "world"); } if (); if (x > 5); ; } } 

Dr. Javier Gonzalez-Sanchez | Compilers | 22 jgs Test Case 01 

Dr. Javier Gonzalez-Sanchez | Compilers | 23 jgs Test Case 02 

Dr. Javier Gonzalez-Sanchez | Compilers | 24 jgs Test Case 02 

Dr. Javier Gonzalez-Sanchez | Compilers | 25 jgs Test Case 02 

Dr. Javier Gonzalez-Sanchez | Compilers | 26 jgs Questions 

jgs Compilers Javier Gonzalez-Sanchez, Ph.D. [email protected] Spring 2026 Copyright. These slides can only be used as study material for the Compilers course at Universidad Panamericana. They cannot be distributed or used for another purpose.