Flags and Hooks

These flags and hooks are availble when MzScheme is used as an embedded interpreter:

•  scheme_exit -- This pointer can be set to a function which takes an integer argument and returns void; the function will be used as the default exit handler. The default is zero.
•  scheme_console_printf -- This pointer can be set to a function that takes arguments like printf; the function will be called to display internal MzScheme warnings and messages. the default is zero.
•  scheme_check_for_break --   This points to a function of no arguments that returns an integer. It is used as the default user-break polling procedure. (A non-zero return value indicates a user break.) The default is zero.
•  scheme_make_stdin,  scheme_make_stdout,  scheme_make_stderr, -- These pointers can be set to a function that takes no arguments and returns a Scheme port Scheme_Object * to be used as the starting standard input, output, and/or error port. The default is zero.
•  scheme_case_sensitive -- If this flag is set to a non-zero value before  scheme_basic_env is called, then MzScheme will not ignore capitalization for synbols and global variable names. The value of this flag should not change once it is set. The default is zero.
•  scheme_constant_builtins -- If this flag is set to a non-zero value before  scheme_basic_env is called, then the standard MzScheme functions and syntax will be defined as constant globals. The default is zero.
•  scheme_no_keywords -- If this flag is set to a non-zero value before  scheme_basic_env is called, then no keywords are enforced; i.e., the names of the core syntactic forms and all ``#%'' names are available for local variable names. The default is zero.
•  scheme_allow_set_undefined -- If this flag is set to a non-zero value, then  set! on an undefined variable will cause it to be defined, rather than resulting in an error. The default is zero.
•  scheme_allow_cond_auto_else -- If this flag is set to zero, then if no clauses match in the evaluation of a  cond or  case form, an exception is raised. If this flag is set to a non-zero value, #<void> is returned. The default is non-zero.
•  scheme_secure_primitive_exn -- If this flag is set to non-zero, then the structure type values and constructors for the primitive exception types will not be defined as global variables. The default is zero.
•  scheme_escape_continuations_only -- If this flag is set to a non-zero value before  scheme_basic_env is called, then  call/cc will be remapped to  call/ec; this is useful for speeding up Scheme evaluation when continuations are only used for escaping. The default is zero.