On this page:
phase?
space?
phase+  space?
phase+  space
phase+  space-phase
phase+  space-space
phase+  space-shift?
phase+  space+
phase+  space-shift+

12.13 Phase and Space Utilities

The bindings documented in this section are provided by the racket/phase+space library, not racket/base or racket.

The racket/phase+space library provides functions for manipulating combined representations of phase levels and binding spaces, particularly as used for require transformers and provide transformers.

When identifier-binding (and related functions, like identifier-transformer-binding), syntax-local-module-exports, syntax-local-module-required-identifiers, module-compiled-exports, or module->exports produces a phase–space combination (or phase–space shift combination), then two such values that are equal? will be eqv?.

Added in version 8.2.0.3 of package base.

procedure

(phase? v)  boolean?

  v : any/c
Returns #t if v is a valid representation of a phase level, #f otherwise. A valid representation is either an exact integer representing a numbered phase level or #f representing the label phase level.

procedure

(space? v)  boolean?

  v : any/c
Returns #t if v is a valid representation of a binding space, #f otherwise. A valid representation is either an interned symbol representing the space whose scope is accessed via make-interned-syntax-introducer, or #f representing the default binding space.

procedure

(phase+space? v)  boolean?

  v : any/c
Returns #t if v is a valid representation of a phase level and binding space combination, #f otherwise. The possible representations are as follows:

procedure

(phase+space phase space)  phase+space?

  phase : phase?
  space : space?
Returns a value to represent the combination of phase and space.

procedure

(phase+space-phase p+s)  phase?

  p+s : phase+space?

procedure

(phase+space-space p+s)  phase?

  p+s : phase+space?
Extracts the phase level or binding space component from a combination.

procedure

(phase+space-shift? v)  boolean?

  v : any/c
Returns #t if v is a valid representation of a phase level shift and binding space shift combination, #f otherwise. A shift can be applied to a combination of a phase level and binding space using phase+shift+. The possible representations of a shift are as follows:

procedure

(phase+space+ p+s shift)  phase+space?

  p+s : phase+space?
  shift : phase+space-shift?
Applies shift to p+s to produce a new combination of phase level and binding space.

procedure

(phase+space-shift+ shift additional-shift)  phase+space-shift?

  shift : phase+space?
  additional-shift : phase+space-shift?
Composes shift and additional-shift to produce a new shift that behaves the same as applying shift followed by additional-shift.