CMPE230 SYSTEMS PROGRAMMING SPRING 2022

PROJECT 1 DOCUMENTATION

• Bahadır Gezer
• Simar Achmet Kechagia

Summary:

Our program behaves like a real compiler. The program reads the input file line by line. Every line is then tokenized, parsed and then translated.

We have implemented our own vector and stack header files. The vector is like the resizable vector in C++ and the stack is the standard stack data structure. Since we don’t know how many Token structs there are the vector is used to hold tokens. This important Vector is called ‘tokens’. Each token is a struct Token structure. This struct holds the type and value of the token. The value char array is the string which the token is named after, and the type is the type which we arbitrarily assigned. The lookup table for types are below.

For every line, after tokenization, tokens Vector is filled with Token structs and these structs does not change places while the current line being read.

Important Notes:

Both compilations must be done with the -lm option. This is to ensure that the <math.h> library is linked properly.

Important Functions:

• void tokenizer(); This function tokenizes the expressions. No attribute is given to the tokens, that is done by the parser() function.

• void parser(); This function parses the expression. It gives meaning to the tokens. More explicitly it will assign types to tokens. It calls get_expression() to get the index of the expected expression. Then it calls expression() to check if the expression syntax is correct. This expression() function uses infix to postfix conversion to check the syntax. This is done with the help of our stack header file.

• void output_generator(File *out); This function takes the Vector tokens, which was attributed in the parser() function, and translates the tokens to appropriate C functions. It behaves just like the parser() in its recursive calls.

Token Types Lookup Table:

• 0 -> scalar keyword
• 1 -> vector keyword
• 2 -> matrix keyword
• 3 -> function keyword (tr, sqrt, choose)
• 4 -> for keyword
• 5 -> left paranthesis
• 6 -> right paranthesis
• 7 -> left square brace
• 8 -> right square brace
• 9 -> left curly brace
• 10 -> right curly brace
• 11 -> equals
• 12 -> multiplication
• 13 -> addition
• 14 -> subtraction
• 15 -> comma
• 16 -> colon
• 17 -> undetermined
• 18 -> comment
• 19 -> scalar variable
• 20 -> vector variable
• 21 -> matrix variable
• 22 -> for variable
• 23 -> print function keyword (print, printsep)
• 24 -> in keyword
• 25 -> indexed matrix
• 26 -> indexed vector
• 27 -> scalar function keyword (choose, sqrt, tr) 28 -> matrix function keyword (tr)