Add pretty-print from Guile.

* module/mes/pretty-print.scm: Import.
* module/mes/pretty-print.mes: Include it.
* AUTHORS: Mention it.

AUTHORS

@@ -32,6 +32,9 @@ module/mes/peg/
 Pmatch from Guile
 module/mes/pmatch.scm
 
+Pretty-print from Guile
+module/mes/pretty-print.scm
+
 Srfi-1 bits from Guile
 module/srfi/srfi-1.scm
 

module/mes/pretty-print.mes

@@ -20,10 +20,8 @@
 
 ;;; Commentary:
 
-;;; base-0.mes is the first file being loaded from the Mes core.  It
-;;; provides primitives that use Mes internals to create the illusion
-;;; of compatibility with Guile.  It is not safe to be run by Guile.
-
 ;;; Code:
 
-(define pretty-print display)
+(mes-use-module (mes guile))
+(mes-use-module (mes optargs))
+(include-from-path "mes/pretty-print.scm")

module/mes/pretty-print.scm

@@ -0,0 +1,278 @@
+;;;; -*-scheme-*-
+;;;;
+;;;; 	Copyright (C) 2001, 2004, 2006 Free Software Foundation, Inc.
+;;;; 
+;;;; This library 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 2.1 of the License, or (at your option) any later version.
+;;;; 
+;;;; This library 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 this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+;;;; 
+(define-module (ice-9 pretty-print)
+  :use-module (ice-9 optargs)
+  :export (pretty-print))
+
+;; From SLIB.
+
+;;"genwrite.scm" generic write used by pretty-print and truncated-print.
+;; Copyright (c) 1991, Marc Feeley
+;; Author: Marc Feeley (feeley@iro.umontreal.ca)
+;; Distribution restrictions: none
+
+(define genwrite:newline-str (make-string 1 #\newline))
+
+(define (generic-write obj display? width per-line-prefix output)
+
+  (define (read-macro? l)
+    (define (length1? l) (and (pair? l) (null? (cdr l))))
+    (let ((head (car l)) (tail (cdr l)))
+      (case head
+        ((quote quasiquote unquote unquote-splicing) (length1? tail))
+        (else                                        #f))))
+
+  (define (read-macro-body l)
+    (cadr l))
+
+  (define (read-macro-prefix l)
+    (let ((head (car l)))
+      (case head
+        ((quote)            "'")
+        ((quasiquote)       "`")
+        ((unquote)          ",")
+        ((unquote-splicing) ",@"))))
+
+  (define (out str col)
+    (and col (output str) (+ col (string-length str))))
+
+  (define (wr obj col)
+    (cond ((and (pair? obj)
+		(read-macro? obj))
+	   (wr (read-macro-body obj)
+	       (out (read-macro-prefix obj) col)))
+	  (else
+	   (out (object->string obj (if display? display write)) col))))
+
+  (define (pp obj col)
+
+    (define (spaces n col)
+      (if (> n 0)
+        (if (> n 7)
+          (spaces (- n 8) (out "        " col))
+          (out (substring "        " 0 n) col))
+        col))
+
+    (define (indent to col)
+      (and col
+           (if (< to col)
+             (and (out genwrite:newline-str col)
+		  (out per-line-prefix 0)
+		  (spaces to 0))
+             (spaces (- to col) col))))
+
+    (define (pr obj col extra pp-pair)
+      (if (or (pair? obj) (vector? obj)) ; may have to split on multiple lines
+        (let ((result '())
+              (left (min (+ (- (- width col) extra) 1) max-expr-width)))
+          (generic-write obj display? #f ""
+            (lambda (str)
+              (set! result (cons str result))
+              (set! left (- left (string-length str)))
+              (> left 0)))
+          (if (> left 0) ; all can be printed on one line
+            (out (reverse-string-append result) col)
+            (if (pair? obj)
+              (pp-pair obj col extra)
+              (pp-list (vector->list obj) (out "#" col) extra pp-expr))))
+        (wr obj col)))
+
+    (define (pp-expr expr col extra)
+      (if (read-macro? expr)
+        (pr (read-macro-body expr)
+            (out (read-macro-prefix expr) col)
+            extra
+            pp-expr)
+        (let ((head (car expr)))
+          (if (symbol? head)
+            (let ((proc (style head)))
+              (if proc
+                (proc expr col extra)
+                (if (> (string-length (symbol->string head))
+                       max-call-head-width)
+                  (pp-general expr col extra #f #f #f pp-expr)
+                  (pp-call expr col extra pp-expr))))
+            (pp-list expr col extra pp-expr)))))
+
+    ; (head item1
+    ;       item2
+    ;       item3)
+    (define (pp-call expr col extra pp-item)
+      (let ((col* (wr (car expr) (out "(" col))))
+        (and col
+             (pp-down (cdr expr) col* (+ col* 1) extra pp-item))))
+
+    ; (item1
+    ;  item2
+    ;  item3)
+    (define (pp-list l col extra pp-item)
+      (let ((col (out "(" col)))
+        (pp-down l col col extra pp-item)))
+
+    (define (pp-down l col1 col2 extra pp-item)
+      (let loop ((l l) (col col1))
+        (and col
+             (cond ((pair? l)
+                    (let ((rest (cdr l)))
+                      (let ((extra (if (null? rest) (+ extra 1) 0)))
+                        (loop rest
+                              (pr (car l) (indent col2 col) extra pp-item)))))
+                   ((null? l)
+                    (out ")" col))
+                   (else
+                    (out ")"
+                         (pr l
+                             (indent col2 (out "." (indent col2 col)))
+                             (+ extra 1)
+                             pp-item)))))))
+
+    (define (pp-general expr col extra named? pp-1 pp-2 pp-3)
+
+      (define (tail1 rest col1 col2 col3)
+        (if (and pp-1 (pair? rest))
+          (let* ((val1 (car rest))
+                 (rest (cdr rest))
+                 (extra (if (null? rest) (+ extra 1) 0)))
+            (tail2 rest col1 (pr val1 (indent col3 col2) extra pp-1) col3))
+          (tail2 rest col1 col2 col3)))
+
+      (define (tail2 rest col1 col2 col3)
+        (if (and pp-2 (pair? rest))
+          (let* ((val1 (car rest))
+                 (rest (cdr rest))
+                 (extra (if (null? rest) (+ extra 1) 0)))
+            (tail3 rest col1 (pr val1 (indent col3 col2) extra pp-2)))
+          (tail3 rest col1 col2)))
+
+      (define (tail3 rest col1 col2)
+        (pp-down rest col2 col1 extra pp-3))
+
+      (let* ((head (car expr))
+             (rest (cdr expr))
+             (col* (wr head (out "(" col))))
+        (if (and named? (pair? rest))
+          (let* ((name (car rest))
+                 (rest (cdr rest))
+                 (col** (wr name (out " " col*))))
+            (tail1 rest (+ col indent-general) col** (+ col** 1)))
+          (tail1 rest (+ col indent-general) col* (+ col* 1)))))
+
+    (define (pp-expr-list l col extra)
+      (pp-list l col extra pp-expr))
+
+    (define (pp-LAMBDA expr col extra)
+      (pp-general expr col extra #f pp-expr-list #f pp-expr))
+
+    (define (pp-IF expr col extra)
+      (pp-general expr col extra #f pp-expr #f pp-expr))
+
+    (define (pp-COND expr col extra)
+      (pp-call expr col extra pp-expr-list))
+
+    (define (pp-CASE expr col extra)
+      (pp-general expr col extra #f pp-expr #f pp-expr-list))
+
+    (define (pp-AND expr col extra)
+      (pp-call expr col extra pp-expr))
+
+    (define (pp-LET expr col extra)
+      (let* ((rest (cdr expr))
+             (named? (and (pair? rest) (symbol? (car rest)))))
+        (pp-general expr col extra named? pp-expr-list #f pp-expr)))
+
+    (define (pp-BEGIN expr col extra)
+      (pp-general expr col extra #f #f #f pp-expr))
+
+    (define (pp-DO expr col extra)
+      (pp-general expr col extra #f pp-expr-list pp-expr-list pp-expr))
+
+    ; define formatting style (change these to suit your style)
+
+    (define indent-general 2)
+
+    (define max-call-head-width 5)
+
+    (define max-expr-width 50)
+
+    (define (style head)
+      (case head
+        ((lambda let* letrec define) pp-LAMBDA)
+        ((if set!)                   pp-IF)
+        ((cond)                      pp-COND)
+        ((case)                      pp-CASE)
+        ((and or)                    pp-AND)
+        ((let)                       pp-LET)
+        ((begin)                     pp-BEGIN)
+        ((do)                        pp-DO)
+        (else                        #f)))
+
+    (pr obj col 0 pp-expr))
+
+  (out per-line-prefix 0)
+  (if width
+    (out genwrite:newline-str (pp obj 0))
+    (wr obj 0))
+  ;; Return `unspecified'
+  (if #f #f))
+
+; (reverse-string-append l) = (apply string-append (reverse l))
+
+(define (reverse-string-append l)
+
+  (define (rev-string-append l i)
+    (if (pair? l)
+      (let* ((str (car l))
+             (len (string-length str))
+             (result (rev-string-append (cdr l) (+ i len))))
+        (let loop ((j 0) (k (- (- (string-length result) i) len)))
+          (if (< j len)
+            (begin
+              (string-set! result k (string-ref str j))
+              (loop (+ j 1) (+ k 1)))
+            result)))
+      (make-string i)))
+
+  (rev-string-append l 0))
+
+(define (pretty-print obj . opts)
+  "Pretty-print OBJ on PORT, which is a keyword argument defaulting to
+the current output port.  Formatting can be controlled by a number of
+keyword arguments: Each line in the output is preceded by the string
+PER-LINE-PREFIX, which is empty by default.  The output lines will be
+at most WIDTH characters wide; the default is 79.  If DISPLAY? is
+true, display rather than write representation will be used.
+
+Instead of with a keyword argument, you can also specify the output
+port directly after OBJ, like (pretty-print OBJ PORT)."
+  (if (pair? opts)
+      (if (keyword? (car opts))
+	  (apply pretty-print-with-keys obj opts)
+	  (apply pretty-print-with-keys obj #:port (car opts) (cdr opts)))
+      (pretty-print-with-keys obj)))
+
+(define* (pretty-print-with-keys obj
+				 #:key 
+				 (port (current-output-port))
+				 (width 79)
+				 (display? #f)
+				 (per-line-prefix ""))
+  (generic-write obj display?
+		 (- width (string-length per-line-prefix))
+		 per-line-prefix
+		 (lambda (s) (display s port) #t)))