IB pseudocode transpiler

This is a transpiler for IB pseudocode to various languages (currently only Python), which includes a lexer and a parser.

Informal specification

The transpiler follows official documents as much as possible:

• Approved notation for developing pseudocode
• Pseudocode in examinations

The far majority of valid IB pseudocode should transpile as intended. Exceptions or clarifications are listed below.

Deviations and extensions

• The not-equals sign is !=, not ≠.
• The division symbol is always div, not /.
• Strings can be multiline; there is no special multiline string syntax.
• The three defined string escape sequences are \n, \t, and \\ for newlines, tabs, and backslashes respectively. If an escape is not in this list, it is interpreted as though the escape backslash were not there; e.g. \a and a are the same.
• Methods or functions are defined as follows. Return statements are optional.

method myMethod(PARAM1, PARAM2)
    // code
    return "my value"
end method

Clarifications

The official specifications leave some behavior undefined, ambiguous, or vague. This section clarifies how the compiler deals with these cases.

• Variables do not need to be and cannot be declared. All variables are global and dynamically typed.
• Comments have no bearing on the program's behavior.
• Classes and associated properties or methods exist internally, but there is currently no way to define or modify them.
• The input command will always treat the input as a string unless it can be parsed into an integer or float. The prompt displayed is always Enter VARIABLE_NAME: where VARIABLE_NAME is the name of the variable.
• The end command does not need to specify what type of block it is ending; for example, both end and end if are acceptable.

Identifier names

• For all identifier names, underscores are allowed anywhere and numbers are allowed except in the first character.
• Variable names [_A-Z][_\dA-Z]* must be all caps.
• Method names [_a-z][_\dA-Za-z]* must begin with a lowercase letter or underscore and have at least one lowercase letter.
• Class names must begin with an uppercase letter but not be all caps.
• Identifiers having only underscores are always interpreted as variable names.

Built-in classes

The items in a given Array, Collection, Stack, or Queue do not all have to be the same type.

• Boolean
• Int
• Float
• Array
• String
• Collection
• Stack
• Queue