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/ C/C++ Users Group Library 1996 July / C-C++ Users Group Library July 1996.iso / vol_200 / 231_01 / generato.st < prev    next >
Text File  |  1987-06-15  |  6KB  |  175 lines
  1. Class Generator :Collection
  2. [
  3.     , aGenerator
  4.         ^ DyadicControlGenerator new;
  5.             firstGen: self
  6.             secondGen: aGenerator
  7.             control: [:x :y |
  8.                 (x isNil)
  9.                     ifTrue:
  10.                         [(y isNil)
  11.                             ifTrue:  [2r01000000]
  12.                             ifFalse: [2r00000101]
  13.                         ]
  14.                     ifFalse: [2r00001010] ]
  15.             compute: [:x | x ]
  16. |
  17.       collect: xformBlock
  18.             ^ MonadicControlGenerator new;
  19.                    initGen: self deepCopy
  20.                    control: [ :x |
  21.                 (x isNil)
  22.                     ifTrue:  [2r1000]
  23.                     ifFalse: [2r0101]
  24.                  ]
  25.                    init: []
  26.                    compute: [:x | xformBlock value: x]
  27. |
  28.     first: limit     | count |
  29.             count <- 0.
  30.         ^ MonadicControlGenerator new;
  31.                    initGen: self deepCopy
  32.                    control: [ :x |
  33.                              (x isNil)
  34.                               ifTrue:  [2r1000]
  35.                               ifFalse: [((count <- count + 1) > limit)
  36.                                              ifTrue:  [2r1000]
  37.                                              ifFalse: [2r0101]
  38.                                         ]
  39.                          ]
  40.                    init: [count <- 0]
  41.                    compute: [:x | x]
  42. |
  43.       select: condBlock
  44.             ^ MonadicControlGenerator new;
  45.                    initGen: self deepCopy
  46.                    control: [ :x |
  47.                          (x isNil)
  48.                               ifTrue:  [2r1000]
  49.                               ifFalse: [(condBlock value: x)
  50.                                              ifTrue:  [2r0101]
  51.                                              ifFalse: [2r0001]
  52.                                         ]
  53.                          ]
  54.                    init: []
  55.                    compute: [:x | x]
  56. |
  57.       until: condBlock
  58.             ^ MonadicControlGenerator new;
  59.                    initGen: self deepCopy
  60.                    control: [ :x |
  61.                          (x isNil)
  62.                               ifTrue:  [2r1000]
  63.                               ifFalse: [(condBlock value: x)
  64.                                              ifTrue:  [2r1000]
  65.                                              ifFalse: [2r0101]
  66.                                         ]
  67.                          ]
  68.                    init: []
  69.                    compute: [:x | x]
  70. |
  71.     with: aGenerator when: conditionBlock
  72.         ^ DyadicControlGenerator new ;
  73.             firstGen: self
  74.             secondGen: aGenerator
  75.             control: [:x :y |
  76.                 (x isNil)
  77.                     ifTrue: [(y isNil)
  78.                         ifTrue:  [2r01000000]
  79.                         ifFalse: [2r00000101] ]
  80.                     ifFalse: [(y isNil)
  81.                         ifTrue:  [2r00001010]
  82.                         ifFalse: [(conditionBlock
  83.                             value: x value: y)
  84.                             ifTrue:  [2r00001010]
  85.                             ifFalse: [2r00000101]
  86.                             ] ] ]
  87.             compute: [:x | x ]
  88. ]
  89.  
  90. Class MonadicControlGenerator :Generator
  91. | subGenerator  currentValue  controlBlock  initBlock  computeBlock |
  92. [
  93.       initGen: aGenerator
  94.     control: conBlk
  95.     init: iniBlk
  96.     compute: cmpBlk
  97.             subGenerator <- aGenerator.
  98.             controlBlock <- conBlk.
  99.             initBlock <- iniBlk.
  100.             computeBlock <- cmpBlk.
  101.             currentValue <- nil
  102. |
  103.       first
  104.             (currentValue <- subGenerator first) isNil
  105.                   ifTrue: [^ nil].
  106.             initBlock value.
  107.             ^ self next
  108. |
  109.       next     | control  returnedValue |
  110.             control <- 0.
  111.             [control anyMask: 2r0100] whileFalse:
  112.                   [
  113.                     control <- controlBlock value: currentValue.
  114.  
  115.                     (control anyMask: 2r1000) ifTrue:
  116.                           [^ nil].
  117.                     (control anyMask: 2r0100) ifTrue:
  118.                           [returnedValue <-
  119.                         computeBlock value: currentValue].
  120.                     (control anyMask: 2r0010) ifTrue:
  121.                           [currentValue <- subGenerator first].
  122.                     (control anyMask: 2r0001) ifTrue:
  123.                     [currentValue <- subGenerator next]
  124.               ].
  125.             ^ returnedValue
  126. ]
  127. Class DyadicControlGenerator :Generator
  128. | firstGenerator secondGenerator
  129.   currentFirst currentSecond
  130.   controlBlock computeBlock |
  131. [
  132.     firstGen: firstGen
  133.     secondGen: secondGen
  134.     control: contBlock
  135.     compute: compBlock
  136.  
  137.                 firstGenerator <- firstGen.
  138.                 secondGenerator <- secondGen.
  139.                 controlBlock <- contBlock.
  140.                 computeBlock <- compBlock
  141.  
  142. |       first
  143.                 currentFirst <- firstGenerator first.
  144.                 currentSecond <- secondGenerator first.
  145.                 (currentFirst isNil & currentSecond isNil) ifTrue: [^ nil].
  146.                 ^ self next
  147.  
  148. |       next        | control returnedValue |
  149.                 control <- 0.
  150.                 [ control anyMask: 2r00001100] whileFalse: [
  151.                   control <- controlBlock value: currentFirst
  152.                                           value: currentSecond.
  153.                    (control allMask: 2r01000000) ifTrue: [^nil].
  154.                    (control allMask: 2r00100000) ifTrue:
  155.                                 [currentFirst <- firstGenerator first].
  156.                    (control allMask: 2r00010000) ifTrue:
  157.                                 [currentSecond <- secondGenerator first].
  158.                    (control allMask: 2r00001100)
  159.                       ifTrue:
  160.                           [returnedValue <- computeBlock
  161.                                value: currentFirst value: currentSecond]
  162.                       ifFalse: [
  163.                          (control allMask: 2r00001000) ifTrue:
  164.                            [returnedValue <- computeBlock value: currentFirst].
  165.                          (control allMask: 2r00000100) ifTrue:
  166.                            [returnedValue <- computeBlock value: currentSecond].
  167.                          ].
  168.                    (control allMask: 2r00000010) ifTrue:
  169.                            [currentFirst <- firstGenerator next].
  170.                    (control allMask: 2r00000001) ifTrue:
  171.                            [currentSecond <- secondGenerator next].
  172.                   ].
  173.                 ^ returnedValue
  174. ]
  175.