You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
pollen/pagemap.rkt

113 lines
3.7 KiB
Racket

#lang racket/base
(require "tools.rkt" "world.rkt" "decode.rkt" sugar txexpr "cache.rkt")
(define+provide current-pagemap (make-parameter #f))
(define+provide (node? x)
(->boolean (and (symbol? x) (try (not (whitespace/nbsp? (->string x)))
(except [exn:fail? (λ(e) #f)])))))
(define+provide (nodeish? x)
(try (node? (->symbol x))
(except [exn:fail? (λ(e) #f)])))
(define/contract+provide (->node x)
(nodeish? . -> . node?)
(->symbol x))
(define+provide/contract (decode-pagemap xs)
(txexpr-elements? . -> . any/c) ; because pagemap is being explicitly validated
(validate-pagemap
(decode (cons world:pagemap-root-node xs)
#:txexpr-elements-proc (λ(xs) (filter (compose1 not whitespace?) xs))
#:string-proc string->symbol))) ; because faster than ->node
(define+provide (validate-pagemap x)
(let ([nodes (pagemap->list x)])
(and
(andmap (λ(p) (or (node? p) (error (format "validate-pagemap: \"~a\" is not a valid node" p)))) nodes)
(try (members-unique?/error nodes)
(except [exn:fail? (λ(e) (error (format "validate-pagemap: ~a" (exn-message e))))]))
x)))
(define+provide (pagemap? x)
(try (->boolean (validate-pagemap x))
(except [exn:fail? (λ(e) #f)])))
;; Try loading from pagemap file, or failing that, synthesize pagemap.
(define+provide/contract (make-project-pagemap project-dir)
(pathish? . -> . pagemap?)
(define pagemap-source (build-path project-dir world:default-pagemap))
(cached-require pagemap-source world:main-pollen-export))
(define+provide/contract (parent p [pagemap (current-pagemap)])
(((or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f node?))
(and pagemap p
(let ([node (->node p)])
(if (member node (map (λ(x) (if (list? x) (car x) x)) (cdr pagemap)))
(car pagemap)
(ormap (λ(x) (parent node x)) (filter list? pagemap))))))
(define+provide/contract (children p [pagemap (current-pagemap)])
(((or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f (listof node?)))
(and pagemap p
(let ([node (->node p)])
(if (equal? node (car pagemap))
(map (λ(x) (if (list? x) (car x) x)) (cdr pagemap))
(ormap (λ(x) (children node x)) (filter list? pagemap))))))
(define+provide/contract (siblings p [pagemap (current-pagemap)])
(((or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f (listof node?)))
(children (parent p pagemap) pagemap))
;; flatten tree to sequence
(define+provide/contract (pagemap->list pagemap)
(pagemap? . -> . (listof node?))
; use cdr to get rid of root tag at front
(cdr (flatten pagemap)))
(define (adjacents side p [pagemap (current-pagemap)])
; ((symbol? (or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f (listof node?)))
(and pagemap p
(let* ([node (->node p)]
[proc (if (equal? side 'left) takef takef-right)]
[result (proc (pagemap->list pagemap) (λ(x) (not (equal? node x))))])
(and (not (empty? result)) result))))
(define+provide/contract (previous* node [pagemap (current-pagemap)])
(((or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f (listof node?)))
(adjacents 'left node pagemap))
(define+provide/contract (next* node [pagemap (current-pagemap)])
(((or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f (listof node?)))
(adjacents 'right node pagemap))
(define+provide/contract (previous node [pagemap (current-pagemap)])
(((or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f node?))
(let ([result (previous* node pagemap)])
(and result (last result))))
(define+provide/contract (next node [pagemap (current-pagemap)])
(((or/c #f nodeish?)) (pagemap?) . ->* . (or/c #f node?))
(let ([result (next* node pagemap)])
(and result (first result))))