* lib/prettyprint.rb (PrettyPrint.singleline_format): new method.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@2944 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 52 insertions, 3 deletions

diff --git a/lib/prettyprint.rb b/lib/prettyprint.rb
index e1b7e7c59a..7f1497b541 100644
--- a/lib/prettyprint.rb
+++ b/lib/prettyprint.rb
@@ -21,7 +21,7 @@ non-string formatting, etc.
 --- PrettyPrint.new([output[, maxwidth[, newline]]]) [{|width| ...}]
     creates a buffer for pretty printing.
 
-    ((|output|)) is a output target.
+    ((|output|)) is an output target.
     If it is not specified, (({''})) is assumed.
     It should have a (({<<})) method which accepts
     the first argument ((|obj|)) of (({PrettyPrint#text})),
@@ -45,12 +45,19 @@ non-string formatting, etc.
     is a convenience method which is same as follows:
 
       begin
-        pp = PrettyPrint.format(output, maxwidth, newline, &genspace)
+        pp = PrettyPrint.new(output, maxwidth, newline, &genspace)
         ...
         pp.flush
         output
       end
 
+--- PrettyPrint.singleline_format([output[, maxwidth[, newline[, genspace]]]]) {|pp| ...}
+    is similar to (({PrettyPrint.format})) but the result has no breaks.
+
+    ((|maxwidth|)), ((|newline|)) and ((|genspace|)) are ignored.
+    The invocation of (({breakable})) in the block doesn't break a line and
+    treated as just an invocation of (({text})).
+
 == methods
 --- text(obj[, width])
     adds ((|obj|)) as a text of ((|width|)) columns in width.
@@ -110,7 +117,7 @@ Christian Lindig, Strictly Pretty, March 2000,
 ((<URL:http://www.gaertner.de/~lindig/papers/strictly-pretty.html>))
 
 Philip Wadler, A prettier printer, March 1998,
-((<URL:http://cm.bell-labs.com/cm/cs/who/wadler/topics/recent.html#prettier>))
+((<URL:http://www.research.avayalabs.com/user/wadler/topics/recent.html#prettier>))
 
 =end
 
@@ -122,6 +129,12 @@ class PrettyPrint
     output
   end
 
+  def PrettyPrint.singleline_format(output='', maxwidth=nil, newline=nil, genspace=nil)
+    pp = SingleLine.new(output)
+    yield pp
+    output
+  end
+
   def initialize(output='', maxwidth=79, newline="\n", &genspace)
     @output = output
     @maxwidth = maxwidth
@@ -340,6 +353,42 @@ class PrettyPrint
       @queue[group.depth].delete(group)
     end
   end
+
+  class SingleLine
+    def initialize(output, maxwidth=nil, newline=nil)
+      @output = output
+      @first = [true]
+    end
+
+    def text(obj, width=nil)
+      @output << obj
+    end
+
+    def breakable(sep=' ', width=nil)
+      @output << sep
+    end
+
+    def nest(indent)
+      yield
+    end
+
+    def group(indent=nil, open_obj='', close_obj='', open_width=nil, close_width=nil)
+      @first.push true
+      @output << open_obj
+      yield
+      @output << close_obj
+      @first.pop
+    end
+
+    def flush
+    end
+
+    def first?
+      result = @first[-1]
+      @first[-1] = false
+      result
+    end
+  end
 end
 
 if __FILE__ == $0