• 1. Compiler Usage

• 2. Language Specification

  • 2.1 Comments
  • 2.2 Identifiers
  • 2.3 Keywords
  • 2.4 Integers
  • 2.5 Reals
  • 2.6 Operators
  • 2.7 Separators

usage: compiler.py [-h] [--print-tokens] [--save-tokens SAVE_TOKENS] [--print-productions] [-s SAVE_PRODUCTIONS] [--symbol-table SYMBOL_TABLE] source file

positional arguments:
  source file           Path to the source code file that will be compiled

options:
  -h, --help            show this help message and exit
  --print-tokens        print tokens returned by lexer
  --save-tokens SAVE_TOKENS
                        Specify output file for tokens
  --print-productions   Print productions to console
  -s SAVE_PRODUCTIONS, --save-productions SAVE_PRODUCTIONS
                        Save syntax analyzer productions to a file
  --symbol-table SYMBOL_TABLE
                        Save symbol table to a file

A comment starts with a [* and ends with a *]. Comments are ignored by the lexical analyzer and syntax analyzer.

[* This is a one line comment *]

[* This is a multiline comment
that spans three rows. All three
rows will be ignored by the compiler. *]

An identifier is a sequence of letters (a - z), digits (0 - 9), and underscores ("_"). The first character in an identifier must be a letter. Case is insignificant, so the lexical analyzer must convert all uppercase letters to lowercase so that all tokens are lowercase.

The following identifiers are keywords of the language and cannot be used for ordinary identifiers.

boolean		else		endif
false		function	if
integer		print		real
return		scan		true
while		endwhile

Integers are unsigned decimal integers. They are a sequence of digits.

Examples of integers

7	153	1849375932

A real is an integer, followed by a dot ("."), followed by an integer. There must be an integer before the dot, and an integer after the dot, meaning that something like 89. or .57 would be invalid.

Examples of reals

3.14	22.5	0.99	25.0

The following tokens are operators.

+	-	*	/
==	!=	>	<
<=	=>	=

The following tokens are separators.

(	)	{	}
,	;	$

Space (' ') is also a separator used to separate tokens and symbols.