Some initial work on nice array formatting [#29].

j/show.j

@@ -286,6 +286,71 @@ function show{T}(a::AbstractArray{T,2})
  show_matrix(a)
 end
 
+alignment(x::Any) = (0, strlen(show_to_string(x)))
+alignment(x::Number) = (strlen(show_to_string(x)), 0)
+function alignment(x::Real)
+ m = match(Regex(L"^(.*?)((?:[\.eE].*)?)$"), show_to_string(x))
+ m == nothing ? (strlen(show_to_string(x)), 0) :
+ (strlen(m.captures[1]), strlen(m.captures[2]))
+end
+function alignment(x::Complex)
+ m = match(Regex(L"^(.*?)(\+.*)$"), show_to_string(x))
+ m == nothing ? (strlen(show_to_string(x)), 0) :
+ (strlen(m.captures[1]), strlen(m.captures[2]))
+end
+function alignment(x::Rational)
+ m = match(Regex(L"^(.*?/)(/.*)$"), show_to_string(x))
+ m == nothing ? (strlen(show_to_string(x)), 0) :
+ (strlen(m.captures[1]), strlen(m.captures[2]))
+end
+function alignment(v::AbstractVector)
+ l = r = 0
+ for x = v
+ a = alignment(x)
+ l = max(l, a[1])
+ r = max(r, a[2])
+ end
+ (l, r)
+end
+
+function alignment(X::AbstractMatrix, cols_if_complete::Int, cols_otherwise::Int, sep::Int)
+ a = {}
+ for j = 1:size(X,2)
+ push(a, alignment(X[:,j][:]))
+ if sum(map(sum,a)) + sep*length(a) >= cols_if_complete
+ pop(a)
+ break
+ end
+ end
+ if length(a) < size(X,2)
+ while sum(map(sum,a)) + sep*length(a) >= cols_otherwise
+ pop(a)
+ end
+ end
+ return a
+end
+
+function show_matrix_ul(X::AbstractMatrix, rows::Int, cols::Int, sep::String)
+ m = size(X,1) < rows ? size(X,1) : rows-1
+ a = alignment(X[1:m,:], cols, cols-4, strlen(sep))
+ for i = 1:m
+ for j = 1:length(a)
+ x = X[i,j]
+ b = alignment(x)
+ l = " "^(a[j][1]-b[1])
+ r = " "^(a[j][2]-b[2])
+ print(l, show_to_string(x), r)
+ if j < length(a)
+ print(sep)
+ end
+ end
+ print(i > 1 || size(X,2) <= length(a) ? "\n" : " ...\n")
+ end
+ if size(X,1) >= rows
+ print("...\n")
+ end
+end
+
 function show_matrix(a::AbstractArray)
  m = size(a,1)
  n = size(a,2)

j/sysimg.j

@@ -75,8 +75,8 @@ set_current_output_stream(make_stdout_stream()) # for error reporting
 load("string.j")
 load("ascii.j")
 load("utf8.j")
-load("show.j")
 load("regex.j")
+load("show.j")
 load("env.j")
 
 # core math functions