Class: Diff

• Inheritance
• Description
• Related information
• Class protocol
  • diffing
  • instance creation
• Instance protocol
  • diffing
  • initialization
  • private
• Private classes
• Examples

Inheritance:

   Object
   |
   +--Diff

Package:

stx:libtool

Category:

Collections-Support

Version:

rev: 1.7 date: 2019/07/07 17:44:59

user: cg

file: Diff.st directory: libtool

module: stx stc-classLibrary: libtool

Author:

Jakub Zelenka (zelenj7@fel.cvut.cz)

Vladislav Skoumal (skoumal@skoumal.net)

Jan Vrany (jan.vrany@fit.cvut.cz)

Description:

I'm standard diff implementation written purely in Smalltalk. I can
compute differences between two sequenceable collections, not necessarily
holding strings. Elements are compared using #=.

Result of comparison is an edit script, a linked list of Diff::Changes,
each keeping one difference: whether change is insert and/or delete,
and positions in A and B.

I'm a port of Java diff.


[instance variables:]

[class variables:]

Related information:

Class protocol:

 between: a and: b

 between: a and: b reverse: reverse

 new

return an initialized instance

Instance protocol:

 a: gA b: gB

Prepare to find differences between two arrays. Each element of
the arrays is translated to an

 diff

 diff: reverse

 diffUsingScript: bld

Get the results of comparison as an edit script. The script
is described by a list of changes. The standard ScriptBuilder
implementations provide for forward and reverse edit scripts.
Alternate implementations could, for instance, list common elements
instead of differences.
@param bld an object to build the script from change flags
@return the head of a list of changes
Some lines are obviously insertions or deletions
because they don't match anything. Detect them now,
and avoid even thinking about them in the main comparison algorithm.

 initialize

konstruktor

 compareseq: gXoff xlim: gXlim yoff: gYoff ylim: gYlim

Compare in detail contiguous subsequences of the two files
which are known, as a whole, to match each other.

The results are recorded in the vectors filevec[N].changedflag, by
storing a 1 in the element for each line that is an insertion or deletion.

The subsequence of file 0 is [XOFF, XLIM) and likewise for file 1.

Note that XLIM, YLIM are exclusive bounds.
All line numbers are origin-0 and discarded lines are not counted.

 diag: anXoff xlim: anXlim yoff: aYoff ylim: aYlim

Give the compiler a chance.

 discardConfusingLines

Discard lines from one file that have no matches in the other file.

 equivMax

 equivMax: something

 filevec

 nodiscards

 nodiscards: something

 shiftBoundaries

Adjust inserts/deletes of blank lines to join changes
as much as possible.

Private classes:

    Change
    Data
    ForwardScript
    ReverseScript

Examples: