Interactive Development F #

Question

Based on the background of Matlab and R, where the development process is very interactive (select, run selection, correct, select, run selection, fix, etc.), I am trying to understand how F # handles this style of development, which seems very important in scientific applications. Here are a few things that immediately come to mind for someone new to F #:

• Selecting multiple rows gives different results than one row at a time.

  let add x y = x + y
  add 4.1 2.3
  

  Selecting both rows yields float -> float -> float, while selecting the first row yields int -> int -> int. More generally, Matlab / R users are used to print the results after each statement, rather than at the end.

• Shadow copying can become burdensome.

  let file = open2GBfile('file.txt')
  process file
  

  If you run it interactively over and over, a 2GB file is copied with a tap and you will quickly run out of memory. Creating a mutable file does not seem like a suitable solution, since the final launch of the program will never change it.

Given these problems, is it not possible for a system based to fsi.exesupport Matlab / R-style interactive development?

[Edit: I guess that 2. For objects marked for deletion as soon as they are shaded?]

Answer 1

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# 1, , , , , inline " " .

# 2 , open process, , . , open :

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• FileStream, process, .
• ,
• ,
• gazillion .

, . Matlab R, , F #, . , .

Answer 2

# 1

FSI ;; :

> 1 + 2;;
val it : int = 3

F # -Codefile , , , .

# 2:

, -, : file , / , ( let ).