Here are the classes, structs, unions and interfaces with brief descriptions:

calc_error
function_error
no_such_function
node
node_add
node_binary
node_divide
node_function
node_function_call
node_identifier
node_impl
node_multiply
node_negate
node_number
node_subtract
node_unary
node_void
parse_error
parser
set_symbol_table
syntax_error