Identifiers & Datatypes

Upper and lowercase letters carry different meaning when at the start of a word.

A Datatype must always start with an uppercase letter, and an identifier must start with either a lowercase letter or an underscore.

Identifier

Identifier        = (underscore | lowercase_letter), identifier_letter*

identifier_letter = underscore | lowercase_letter | uppercase_letter | decimal_digit

identifier
╰╴No statement matched
_identifier
_123
_many_letters
camelCase
thp

Datatype

Datatype = uppercase_letter, indentifier_letter*

Datatype
╰╴No statement matched
PDO
WEIRD_DATATYPE
thp

Keywords

The following are (currently) THP keywords:

val     Expected an identifier here, found a K_Varvar     fun
        ╰╴Invalid variable declaration
thp

Keywords are scanned first as identifiers, then transformed to their respective tokens.