Grammar Reference

This is the practical grammar reference for ENG v0.1.0.

Program

program ::= statement* EOF

Let IDENT be expression.
Make IDENT be expression.
Set IDENT to expression.

Example:

engling
Let x be 5.
Set x to x plus 1.

Print expression.
Show expression.
Display expression.

Show and Display are lexer aliases for Print.

Conceptually:

expression
  -> or
  -> and
  -> comparison
  -> addition
  -> multiplication
  -> primary

Primary values include numbers, strings, booleans, identifiers, function calls, and list access.

If expression, then
    statements
Otherwise
    statements
End.

Otherwise is optional.

Repeat expression times
    statements
End.

While expression
    statements
End.

Return form:

Define a function called NAME that takes PARAMETERS and returns EXPRESSION.

Body form:

Define a function called NAME that takes PARAMETERS
    statements
End.

nothing represents an empty parameter list.

Run NAME.
Run NAME with ARGUMENTS.

Call is accepted as a lexer alias for Run.

Make a list called NAME.
Add EXPRESSION to NAME.
Get the ORDINAL item of NAME.
Set the ORDINAL item of NAME to EXPRESSION.
Print the length of NAME.

Import NAME.
From NAME use IDENTIFIER.
From NAME use IDENTIFIER and IDENTIFIER.

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