fixing last value of for loop

  for i=a:b  should be the same as
  R=a:b; for i=R
need to change some loops in eig/eigs that modify the loop variable
restoring behavior of let

Author: JeffBezanson

j/io.j

@@ -261,7 +261,8 @@ function del_all(s::FDSet)
     s
 end
 
-let tv = Array(Uint8, long(ccall(:jl_sizeof_timeval, Int32, ())))
+begin
+    local tv = Array(Uint8, long(ccall(:jl_sizeof_timeval, Int32, ())))
     global select_read
     function select_read(readfds::FDSet, timeout::Real)
         if timeout == Inf

j/linalg_arpack.j

@@ -232,14 +232,16 @@ function eigs{T}(A::AbstractMatrix{T}, k::Int, evtype::ASCIIString)
         return (d, v[1:n, 1:nev])
     else
         evec = complex(zeros(T, n, nev+1), zeros(T, n, nev+1))
-        for j=1:nev
+        j = 1
+        while j <= nev
             if di[j] == 0.0
                 evec[:,j] = v[:,j]
             else
                 evec[:,j]   = v[:,j] + im*v[:,j+1]
                 evec[:,j+1] = v[:,j] - im*v[:,j+1]
                 j += 1
             end
+            j += 1
         end
         return (complex(dr[1:nev],di[1:nev]), evec[1:n, 1:nev])
     end

j/linalg_lapack.j

@@ -416,14 +416,16 @@ function eig{T<:Union(Float64,Float32,Complex128,Complex64)}(A::Matrix{T})
             return (W, VR)
         else
             evec = complex(zeros(T, n, n), zeros(T, n, n))
-            for j=1:n
+            j = 1
+            while j <= n
                 if WI[j] == 0.0
                     evec[:,j] = VR[:,j]
                 else
                     evec[:,j]   = VR[:,j] + im*VR[:,j+1]
                     evec[:,j+1] = VR[:,j] - im*VR[:,j+1]
                     j += 1
                 end
+                j += 1
             end
             return (complex(WR, WI), evec)
         end

j/math_libm.j

@@ -108,7 +108,8 @@ ldexp(x::Float32,e::Int32) = ccall(dlsym(libfdm, :ldexpf), Float32, (Float32,Int
 # TODO: vectorize does not do the right thing for these argument types
 #@vectorize_2arg Real ldexp
 
-let exp::Array{Int32,1} = zeros(Int32,1)
+begin
+    local exp::Array{Int32,1} = zeros(Int32,1)
     global frexp
     function frexp(x::Float64)
         s = ccall(dlsym(libfdm,:frexp), Float64, (Float64, Ptr{Int32}), x, exp)

j/string.j

@@ -800,7 +800,8 @@ hex(n::Union(Int,Float), l::Int) = lpad(hex(n), l, '0')
 
 ## string to float functions ##
 
-let tmp::Array{Ptr{Uint8},1} = Array(Ptr{Uint8},1)
+begin
+    local tmp::Array{Ptr{Uint8},1} = Array(Ptr{Uint8},1)
     global float64, float32
     function float64(s::String)
         s = cstring(s)

src/julia-syntax.scm

@@ -460,18 +460,20 @@
    ;; let
    (pattern-lambda (let ex . binds)
 		   (let loop ((binds binds)
+			      (args  ())
+			      (inits ())
 			      (locls ())
 			      (stmts ()))
 		     (if (null? binds)
-			 `(call (-> (tuple)
+			 `(call (-> (tuple ,@args)
 				    (block (local (vars ,@locls))
 					   ,@stmts
 					   ,ex))
-				)
+				,@inits)
 			 (cond
 			  ((or (symbol? (car binds)) (decl? (car binds)))
 			   ;; just symbol -> add local
-			   (loop (cdr binds)
+			   (loop (cdr binds) args inits
 				 (cons (car binds) locls)
 				 stmts))
 			  ((and (length= (car binds) 3)
@@ -480,17 +482,20 @@
 			   (cond
 			    ((or (symbol? (cadar binds))
 				 (decl?   (cadar binds)))
-			     ;; a=b -> add local and initializer
+			     ;; a=b -> add argument
 			     (loop (cdr binds)
-				   (cons (cadar binds) locls)
-				   (cons `(= ,(decl-var (cadar binds))
+				   (cons (cadar binds) args)
+				   (cons (caddar binds) inits)
+				   locls stmts))
+				   #;(cons (cadar binds) locls)
+				   #;(cons `(= ,(decl-var (cadar binds))
 					     ,(caddar binds))
-					 stmts)))
+					 stmts);))
 			    ((and (pair? (cadar binds))
 				  (eq? (caadar binds) 'call))
 			     ;; f()=c
 			     (let ((asgn (cadr (julia-expand0 (car binds)))))
-			       (loop (cdr binds)
+			       (loop (cdr binds) args inits
 				     (cons (cadr asgn) locls)
 				     (cons asgn stmts))))
 			    (else (error "invalid let syntax"))))
@@ -738,22 +743,24 @@
 				    (break-block loop-cont
 						 ,body)
 				    (= ,cnt (call + 1 ,cnt))))))))
-	  (let ((lim (if (number? b) b (gensy))))
+	  (let ((cnt (gensy))
+		(lim (if (number? b) b (gensy))))
 	    `(scope-block
 	     (block
-	      (= ,var ,a)
+	      (= ,cnt ,a)
 	      ,@(if (eq? lim b) '() `((= ,lim ,b)))
 	      (break-block loop-exit
-			   (_while (call <= ,var ,lim)
+			   (_while (call <= ,cnt ,lim)
 				   (block
+				    (= ,var ,cnt)
 				    (break-block loop-cont
 						 ,body)
-				    (= ,var (call +
+				    (= ,cnt (call +
 						  (call (top convert)
 							(call (top typeof)
-							      ,var)
+							      ,cnt)
 							1)
-						  ,var)))))))))))
+						  ,cnt)))))))))))
 
    ; for loop over arbitrary vectors
    (pattern-lambda

test/perf.j

@@ -50,11 +50,12 @@ function mandel(z::Complex)
     c = z
     for n=0:79
         if abs(z)>2
+            n -= 1
             break
         end
         z = z^2+c
     end
-    n
+    n+1
 end
 
 mandelperf() = [ mandel(complex(r,i)) | r=-2.0:.1:0.5, i=-1.:.1:1. ]