9.2.900
17 let-in binding and destructuring form
| (require phc-toolkit/percent) | package: phc-toolkit |
The forms in this module may possibly be moved to a separate package, as part of the template library described in Versatile parser and template library (for now the template library is not implemented yet).
syntax
(% parallel-binding … maybe-in body …)
parallel-binding = binding and parallel-binding | binding binding = pattern … = expr maybe-in =
| in expr = expression
Locally binds the variables in the patterns to the
expr. Each binding clause should contain as many
patterns as expr produces values. The
body … forms are evaluated with the given
variables bound.
The bindings are executed in sequence, as if bound with let*, unless grouped using and, in which case they are executed in parallel, as if bound with let.
NOTE: TODO: for now bindings are run in sequence, and parallel bindings have not been implemented yet.
syntax
This identifier is only valid in certain forms, like
(% x = 10 in (+ x x)). It is an error to use it as
an expression otherwise.
syntax
(define% (name pattern …) body …)
pattern = variable | [variable : type] | cons-pattern | list-pattern | vector-pattern cons-pattern = (pattern . pattern) | (pattern :: pattern) list-pattern = (pattern …) | (pattern … :: tail-pattern) tail-pattern = pattern vector-pattern = #(pattern …) variable = identifier
Locally binds the variables in the patterns to the
expr. Each binding clause should contain as many
patterns as expr produces values. The
body … forms are evaluated with the given
variables bound.
The bindings are executed in parallel, as if bound with let.
17.1 Untyped versions of percent
| (require phc-toolkit/untyped/percent) | package: phc-toolkit |