daniel-vera-g/imp-language

Simple imperative language

IMP - Project

Simple imperative language

About

Implementation of simple compiler with the following functionalities:

1. Parser :

• Parses a given Program, Statement, Expression,... to a proper AST that can be further processed
• For example: 1+0 -> plus(number(1), number(0))

2. Type checker :

• Checks the types of the given Programm, Statement,...
• For example: 1 -> int

3. Evaluator :

• Evaluates the given Expression
• For example: 1+0 -> 1

Syntax definition:

vars       Variable names, start with lower-case letter

prog      ::= block
block     ::= "{" statement "}"
statement ::=  statement ";" statement           -- Command sequence
            |  vars ":=" exp                     -- Variable declaration
            |  vars "=" exp                      -- Variable assignment
            |  "while" exp block                 -- While
            |  "if" exp block "else" block       -- If-then-else
            |  "print" exp                       -- Print

exp ::= 0 | 1 | -1 | ...     -- Integers
     | "true" | "false"      -- Booleans
     | exp "+" exp           -- Addition
     | exp "*" exp           -- Multiplication
     | exp "||" exp          -- Disjunction
     | exp "&&" exp          -- Conjunction
     | "!" exp               -- Negation
     | exp "==" exp          -- Equality test
     | exp "<" exp           -- Lesser test
     | "(" exp ")"           -- Grouping of expressions
     | vars                  -- Variables

Usage

1. Build: go build main.go
2. Run: ./imp-project 'x := 1+2*3;' (First parameter is Program to compile)
3. Run tests: go test -v

References

• Based on: https://sulzmann.github.io/ModelBasedSW/imp.html (See lecture notes)
• Used Parser(Pratt Parser):
  • https://dl.acm.org/doi/10.1145/512927.512931
  • https://crockford.com/javascript/tdop/tdop.html