Initial data commit

Task/Execute-a-Markov-algorithm/11l/execute-a-markov-algorithm.11l

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+T Rule
+   String pattern
+   String replacement
+   Bool terminating
+   F (pattern, replacement, terminating)
+      .pattern = pattern
+      .replacement = replacement
+      .terminating = terminating
+
+F parse(rules)
+   [Rule] result
+   L(line) rules.split("\n")
+      I line.starts_with(‘#’)
+         L.continue
+      I line.trim(‘ ’).empty
+         L.continue
+
+      V (pat, rep) = line.split(‘ -> ’)
+
+      V terminating = 0B
+      I rep.starts_with(‘.’)
+         rep = rep[1..]
+         terminating = 1B
+
+      result.append(Rule(pat, rep, terminating))
+   R result
+
+F apply(text, rules)
+   V result = text
+   V changed = 1B
+
+   L changed == 1B
+      changed = 0B
+      L(rule) rules
+         I rule.pattern C result
+            result = result.replace(rule.pattern, rule.replacement)
+            I rule.terminating
+               R result
+            changed = 1B
+            L.break
+
+   R result
+
+V SampleTexts = [‘I bought a B of As from T S.’,
+                 ‘I bought a B of As from T S.’,
+                 ‘I bought a B of As W my Bgage from T S.’,
+                 ‘_1111*11111_’,
+                 ‘000000A000000’]
+
+V RuleSets = [
+‘# This rules file is extracted from Wikipedia:
+# http://en.wikipedia.org/wiki/Markov_Algorithm
+A -> apple
+B -> bag
+S -> shop
+T -> the
+the shop -> my brother
+a never used -> .terminating rule’,
+
+‘# Slightly modified from the rules on Wikipedia
+A -> apple
+B -> bag
+S -> .shop
+T -> the
+the shop -> my brother
+a never used -> .terminating rule’,
+
+‘# BNF Syntax testing rules
+A -> apple
+WWWW -> with
+Bgage -> ->.*
+B -> bag
+->.* -> money
+W -> WW
+S -> .shop
+T -> the
+the shop -> my brother
+a never used -> .terminating rule’,
+
+‘### Unary Multiplication Engine, for testing Markov Algorithm implementations
+### By Donal Fellows.
+# Unary addition engine
+_+1 -> _1+
+1+1 -> 11+
+# Pass for converting from the splitting of multiplication into ordinary
+# addition
+1! -> !1
+,! -> !+
+_! -> _
+# Unary multiplication by duplicating left side, right side times
+1*1 -> x,@y
+1x -> xX
+X, -> 1,1
+X1 -> 1X
+_x -> _X
+,x -> ,X
+y1 -> 1y
+y_ -> _
+# Next phase of applying
+1@1 -> x,@y
+1@_ -> @_
+,@_ -> !_
+++ -> +
+# Termination cleanup for addition
+_1 -> 1
+1+_ -> 1
+_+_ -> ’,
+
+‘# Turing machine: three-state busy beaver
+#
+# state A, symbol 0 => write 1, move right, new state B
+A0 -> 1B
+# state A, symbol 1 => write 1, move left, new state C
+0A1 -> C01
+1A1 -> C11
+# state B, symbol 0 => write 1, move left, new state A
+0B0 -> A01
+1B0 -> A11
+# state B, symbol 1 => write 1, move right, new state B
+B1 -> 1B
+# state C, symbol 0 => write 1, move left, new state B
+0C0 -> B01
+1C0 -> B11
+# state C, symbol 1 => write 1, move left, halt
+0C1 -> H01
+1C1 -> H11’]
+
+L(ruleset) RuleSets
+   V rules = parse(ruleset)
+   print(apply(SampleTexts[L.index], rules))