Functions can be marked for inlining using (declaim (inline symbol…​)) form.

Following extra functions are provided to complement standard file / stream api.

(closed-p stream)

Returns t if stream had been explicitly closed, nil otherwise. A nil result doesn’t guarantee the stream is operable.

(delete-file path-string)

Deletes a file a under given path string if it exists. It’s not an error if it doesn’t. Returns nil.

Truffle ISLISP provides a very simple module system, somewhat inspired by Racket. A module is colloquial to a file that defines its source.

Use (requires path-string …​) to load modules; for example

Use (provides symbol …​) to define module’s exports that will be used by modules that required it; for example

The module paths are searched relative to sourcepath roots, which defaults to working directory. You can specify sourcepaths using islisp.Sourcepath (when using polyglot / embedding), or using -sp / --sourcepath when using standalone launcher. The value in both cases is root paths separated by system path separator.

For example; given the following files

Where main.lisp starts with

The correct invocation is islisp -sp root1:root2 main.lisp (on linux); islisp -sp root1;root2 main.lisp (on windows).

Some modules are built-in, their name starts with "builtin/".

(debugger) statement enables triggering debugger breakpoint from code. Works only when ran in debug mode. Returns nil.

(trace form …​) macro prints expression representation and its value to error stream, and returns the value.

Conditions get stacktrace attached upon signalling by default. Stacktrace gather can be disabled for condition types by implementing method (fill-stacktrace condition-class) and returning nil from it.

Stacktrace can be inspected using generic method (condition-stacktrace condition). A stacktrace is a vector of elements, where each element is itself a vector. Element’s vector consists of: source name, start line, start column, end line, end column. Condition stacktraces are printed during report-condition. Stacktrace printing can be modified by changing dynamic variable *stacktrace-formatter* and assigning it a formatter function which takes output stream as the first argument, stacktrace as the second, and writes necessary presentation to the stream.

You can eval any at runtime present truffle language code using (eval language-code source-code); for example

interop language’s values are mapped to most fit ISLISP type. For some values, special procedures are given, see Truffle object api.

External objects with fields are represented as instances of <truffle-object> class (which is subclass of <object>). You can get a vector of fields (as strings) in a given object using (truffle-object-fields truffle-obj).

Use (truffle-object-field truffle-obj field) to read a field of a truffle value, where field is a string name of the field.

Use (truffle-object-set-field value truffle-obj field) or (setf (truffle-object-field truffle-obj field) value) to set a field value on a truffle object.

Interop arrays are presented as objects of class <truffle-vector>. The class extends`<basic-vector>` therefore the common vector / sequence methods can be used.

Interop errors are signalled using <truffle-interop-error> class (which extends <error>). You can retrieve attached message using (truffle-interop-error-message interop-error-condition).

Truffle NFI internal language is provided through transparent interface. First, load the dynamic library using (load-native-library name), which will return an object represented by class <truffle-native-library>. To extract a binding out of the library, call (native-library-symbol symbol-name signature). See truffle documentation regarding details on how to define signature string.

Application can have early exit using (exit exit-code), where exit-code is an integer.