add utils file and start implementation of links

Makefile.am

@@ -4,6 +4,7 @@ moddir=$(prefix)/share/guile/site/2.0
 godir=$(prefix)/share/guile/site/2.0
 
 SOURCES =                           \
+  commonmark/utils.scm              \
   commonmark/node.scm               \
   commonmark/blocks.scm             \
   commonmark/inlines.scm            \

commonmark/blocks.scm

@@ -19,6 +19,7 @@
   #:use-module (ice-9 regex)
   #:use-module (ice-9 rdelim)
   #:use-module (commonmark node)
+  #:use-module (commonmark utils)
   #:export (parse-blocks))
 
 ;; String -> String
@@ -251,6 +252,16 @@
 (define (make-paragraph line)
   (make-paragraph-node line))
 
+(define (parse-reference-definition n col)
+  (cond ((not (node? n)) (col n '()))
+        ((paragraph-node? n) (col n '(p)))
+        (else (map&co parse-reference-definition (node-children n)
+                      (lambda (v d)
+                        (col (make-node (node-type n)
+                                        (node-data n)
+                                        v)
+                             d))))))
+
 
 ;; Line is one of:
 ;;  - String

commonmark/node.scm

@@ -20,6 +20,7 @@
   #:use-module (srfi srfi-9)
   #:use-module (srfi srfi-26)
   #:export (make-node
+            node?
             node-type
             node-children
             node-data

commonmark/utils.scm

@@ -0,0 +1,34 @@
+;; Copyright (C) 2015  Erik Edrosa <erik.edrosa@gmail.com>
+;;
+;; This file is part of guile-commonmark
+;;
+;; guile-commonmark is free software: you can redistribute it and/or
+;; modify it under the terms of the GNU Lesser General Public License
+;; as published by the Free Software Foundation, either version 3 of
+;; the License, or (at your option) any later version.
+;;
+;; guile-commonmark is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU Lesser General Public License for more details.
+;;
+;; You should have received a copy of the GNU Lesser General Public License
+;; along with guile-commonmark.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (commonmark utils)
+  #:export (map&co))
+
+
+;; f: (a k' -> d)
+;; k': b (listof c) -> d
+;; l: (listof a)
+;; k: (listof b) (listof c) -> d
+;; f l k -> d
+(define (map&co f l k)
+  "like map but uses a continuation to collect an extra list of values"
+  (if (null? l)
+      (k '() '())
+      (f (car l) (lambda (v d)
+                   (map&co f (cdr l)
+                           (lambda (v2 d2)
+                             (k (cons v v2) (append d d2))))))))