Winter 2012-2013 Compiler Principles Scanning Assignment

1. Winter 2012-2013Compiler PrinciplesScanning Assignment Mayer Goldberg and Roman Manevich Ben-Gurion University

2. Overview • Goal: implement scanner using Jflex forTable Processing Language (TPL) • Use supplied skeleton Java sources • Optionally (recommended) use build.xml to automate tasks with Ant • Complete TPL.lex to handle all token kinds • Test on example programs • Write your own test suite of TPL programs • Correct and erroneous • Don’t forget to handle comments, quoted strings + escape sequences, errors

3. Example program // A constraint on the number of columns in the input table.assert COLS == 3 : "Number of columns should be:t3“COLS2 = COLS * 2 // This defines a constant COLS2// This is a function definition. x and y a argument variables.def weirdAverage(x, y) = { x * y / (x + y)}// This is the definition of the first column.def TABLE[i==1][j] = {TABLE[1][j] * -18.7}// This column definition simply copies the values from the first input column.def TABLE[i==2]ji] = {TABLE[1][j]}/* This is a multi-line comment.def TABLE[i==2][j] = {TABLE[1][j] * -1}*/def TABLE[i==3][j] = {if (TABLE[2][j] + TABLE[3][j] > 0) {weirdAverage(TABLE[2][j], TABLE[3][j]) }else { 0 }}def TABLE[i==4][j] = {if (j < ROWS) { 0 }else {sum = 0for (k = 1..ROWS)sum += TABLE[1][k]average /= ROWS }}

4. Assertions // A constraint on the number of columns in the input table.assert COLS == 3 : "Number of columns should be:t3“

5. Constants COLS2 = COLS * 2 // This defines a constant COLS2

6. Functions // This is a function definition. x and y a argument variables.def weirdAverage(x, y) = { x * y / (x + y)}

7. Columns // This is the definition of the first column.def TABLE[i==1][j] = {TABLE[1][j] * -18.7}// This column definition simply copies the values from the first input column.def TABLE[i==2]ji] = {TABLE[1][j]}/* This is a multi-line comment.def TABLE[i==2][j] = {TABLE[1][j] * -1}*/

8. Columns def TABLE[i==3][j] = {if (TABLE[2][j] + TABLE[3][j] > 0) {weirdAverage(TABLE[2][j], TABLE[3][j]) }else { 0 }}def TABLE[i==4][j] = {if (j < ROWS) { 0 }else {sum = 0for (k = 1..ROWS)sum += TABLE[1][k]average /= ROWS }}

9. Grammar - tokens idIdentiertoken num Number token quote Quoted string token

10. Grammar - productions