CS 3040 Sample Solutions

CS 3040 Sample Programs and Problems

Python

BLTL Interpreter:
- btl_syntax.py: classes to represent BTL programs
- btl_interpreter.py: evaluating BTL programs
- test_btl_interpreter.py
fact.py: Python implementation of factorial
readinput.py: read (multiple lines of standard input into a string and break the string into words at spaces

Haskell

myDrop.hs: a recursive re-implementation of Haskell's drop function. patternDrop.hs computes the same result but using patterns in the argument lists. These are discussed in the week 3 notes.

A Haskell implementation of a finite state machine

card.hs: a short example illustrating defining a data type and writing a function processing that type.

Top-down, bottom-up parsers

nats.hs: Natural numbers

C++

simple-expr-recognizer.cpp: a recursive-descent parser implementing an expression recognizer. This serves as an introduction to recursive descent parsing.

simple-expr.cpp: expression parser with evaluation.

expr.cpp: recursive-descent parser for expressions over +, -, *, /, (, and )

To compile:
```
        g++ -o expr expr.cpp
```
To run: enter the expression on the command line, with a space around each token:
```
        ./expr 3 + 4 - 5
```
The dot at the start (./) is necessary because there's a more full-fledged version of expr that comes standard on Unix systems.
Note: (, ), and * are special characters, so you'd want to escape them at the command-line prompt:
```
        ./expr 18 \* \( 3 - 12 / 2 \)
```
fact.cpp: C++ implementation of factorial for discussion on semantics

ANTLR

All ANTLR examples