Execute a Markov algorithm: Difference between revisions

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@@ Line 770: / Line 770: @@
 }
 </lang>
+=={{header|Go}}==
+<lang go>package main
+import (
+    "fmt"
+    "strings"
+)
+type testCase struct {
+    ruleSet, sample, output string
+}
+var testSet []testCase // initialized in separate source file
+func main() {
+    for i, tc := range testSet {
+        if r := ma(tc.ruleSet, tc.sample); r != tc.output {
+            fmt.Println("test", i+1, "fail")
+        }
+    }
+}
+type rule struct {
+    pat  string
+    rep  string
+    term bool
+}
+func ma(rs, s string) string {
+    // compile rules per task description
+    var rules []rule
+    for _, line := range strings.Split(rs, "\n", -1) {
+        if line == "" || line[0] == '#' {
+            continue
+        }
+        a := strings.Index(line, "->")
+        if a == -1 {
+            fmt.Println("invalid rule:", line)
+            return ""
+        }
+        pat := line[:a]
+        for {
+            if pat == "" {
+                b := strings.Index(line[a+2:], "->")
+                if b == -1 {
+                    fmt.Println("invalid rule:", line)
+                    return ""
+                }
+                a += 2 + b
+                pat = line[:a]
+                continue
+            }
+            last := pat[len(pat)-1]
+            if last != ' ' && last != '\t' {
+                break
+            }
+            pat = pat[:len(pat)-1]
+        }
+        rep := line[a+2:]
+        for rep > "" && (rep[0] == ' ' || rep[0] == '\t') {
+            rep = rep[1:]
+        }
+        var term bool
+        if rep > "" && rep[0] == '.' {
+            term = true
+            rep = rep[1:]
+        }
+        rules = append(rules, rule{pat, rep, term})
+    }
+    // execute algorithm per WP
+    for r := 0; r < len(rules); {
+        pat := rules[r].pat
+        if f := strings.Index(s, pat); f == -1 {
+            r++
+        } else {
+            s = s[:f] + rules[r].rep + s[f+len(pat):]
+            if rules[r].term {
+                break
+            }
+            r = 0
+        }
+    }
+    return s
+}</lang>
 =={{header|Haskell}}==