Merge pull request #196 from diagrams/cat-sep

add convenience synonyms [hv]sep for [hv]cat' (with & sep .~ x)

src/Diagrams/TwoD.hs

@@ -201,8 +201,8 @@ module Diagrams.TwoD
          -- * Combinators
          -- ** Combining multiple diagrams
        , (===), (|||), atAngle
-       , hcat, hcat'
-       , vcat, vcat'
+       , hcat, hcat', hsep
+       , vcat, vcat', vsep
 
          -- ** Spacing and envelopes
        , strutX, strutY

src/Diagrams/TwoD/Combinators.hs

@@ -21,8 +21,8 @@ module Diagrams.TwoD.Combinators
       (===), (|||), atAngle
 
       -- * n-ary combinators
-    , hcat, hcat'
-    , vcat, vcat'
+    , hcat, hcat', hsep
+    , vcat, vcat', vsep
 
       -- * Spacing/envelopes
     , strutR2
@@ -37,6 +37,7 @@ module Diagrams.TwoD.Combinators
 
     ) where
 
+import           Control.Lens ((&), (.~))
 import           Data.AffineSpace
 import           Data.Colour
 import           Data.Default.Class
@@ -116,11 +117,18 @@ hcat = hcat' def
 
 -- | A variant of 'hcat' taking an extra 'CatOpts' record to control
 --   the spacing.  See the 'cat'' documentation for a description of
---   the possibilities.
+--   the possibilities. For the common case of setting just a
+--   separation amount, see 'hsep'.
 hcat' :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2)
       => CatOpts R2 -> [a] -> a
 hcat' = cat' unitX
 
+-- | A convenient synonym for horizontal concatenation with
+--   separation: @hsep s === hcat' (with & sep .~ s)@.
+hsep :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2)
+     => Scalar R2 -> [a] -> a
+hsep s = hcat' (def & sep .~ s)
+
 -- | Lay out a list of juxtaposable objects in a column from top to
 --   bottom, so that their local origins lie along a single vertical
 --   line, with successive envelopes tangent to one another.
@@ -137,12 +145,19 @@ vcat :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2)
 vcat = vcat' def
 
 -- | A variant of 'vcat' taking an extra 'CatOpts' record to control
---   the spacing.  See the 'cat'' documentation for a description of the
---   possibilities.
+--   the spacing.  See the 'cat'' documentation for a description of
+--   the possibilities.  For the common case of setting just a
+--   separation amount, see 'vsep'.
 vcat' :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2)
       => CatOpts R2 -> [a] -> a
 vcat' = cat' (negateV unitY)
 
+-- | A convenient synonym for vertical concatenation with
+--   separation: @vsep s === vcat' (with & sep .~ s)@.
+vsep :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2)
+     => Scalar R2 -> [a] -> a
+vsep s = vcat' (def & sep .~ s)
+
 -- | @strutR2 v@ is a two-dimensional diagram which produces no
 --   output, but with respect to alignment, envelope, /and trace/ acts
 --   like a 1-dimensional segment oriented along the vector @v@, with