source: project/release/5/slib-prec/trunk/slib-prec-grammar.scm @ 38716

;;;; slib-prec-grammar.scm  -*- Scheme -*-
;;;; Kon Lovett, Apr '20
;;;; Kon Lovett, Apr '18

(module slib-prec-grammar

(;export
  ;
  active-grammar active-grammar-set!
  active-input-grammar active-output-grammar active-echo-grammar
  read-syntax-setup!
  ;
  make-grammar
  grammar?
  grammar-name
  grammar-reader
  grammar-read-tab
  grammar-writer
  grammar-write-tab
  ;
  grammar-id-name-set!
  grammar-id-name
  list-of-grammar-ids
  count-of-grammar-ids
  clear-grammar-ids
  grammar-id-name-setup!
  ;
  defgrammar
  get-grammar
  list-of-grammars
  count-of-grammars
  get-grammar/id
  clear-grammars
  ;
  make-delimited-parse-grammar-reader
  read-sexp
  write-sexp
  print-using-grammar
  flush-input-whitespace)

(import scheme)
(import (chicken base))
(import (chicken type))
(import slib-prec-parse)

;;;

(include "slib-compat")
(include "slib-grammar")

;;

(define *input-grammar*)
(define *output-grammar*)
(define *echo-grammar*)

(define (active-grammar-set! input output #!optional (echo 'null))
  (set! *input-grammar* (get-grammar input))
  (set! *output-grammar* output)
  (set! *echo-grammar* echo) )

(define (active-grammar)
  (values *input-grammar* *output-grammar* *echo-grammar*) )

(define (active-input-grammar) (receive (i o e) (active-grammar) i))
(define (active-output-grammar) (receive (i o e) (active-grammar) o))
(define (active-echo-grammar) (receive (i o e) (active-grammar) e))

;;

(define (read-syntax-setup!)
  (import (only (chicken base) parentheses-synonyms))
  (import (only (chicken read-syntax) set-sharp-read-syntax! set-parameterized-read-syntax!))
  (set-sharp-read-syntax! #\{
    (lambda (port)
      (parameterize ((parentheses-synonyms #f))
        (read-delimited-sexp port #\} (get-grammar/id 0) 0))))
  (set-parameterized-read-syntax! #\{
    (lambda (port id)
      (parameterize ((parentheses-synonyms #f))
        (read-delimited-sexp port #\} (get-grammar/id id) 0)))) )

) ;slib-prec-grammar