Wildcard.hpp

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#pragma once
 
namespace slang::netlist {

inline auto wildcardMatch(const char *text, const char *pattern) -> bool {
  while (*pattern != '\0') {
    // Detect a recursive wildcard token at the current pattern
    // position, optionally preceded by a `.` we can absorb as part
    // of a segment-boundary match.
    bool hasLead = false;
    const char *p = pattern;
    if (*p == '.') {
      const char *q = p + 1;
      bool isRecur = (q[0] == '*' && q[1] == '*') ||
                     (q[0] == '.' && q[1] == '.' && q[2] == '.');
      if (isRecur) {
        hasLead = true;
        p = q;
      }
    }
 
    int recurLen = 0;
    if (p[0] == '*' && p[1] == '*') {
      recurLen = 2;
    } else if (p[0] == '.' && p[1] == '.' && p[2] == '.') {
      recurLen = 3;
    }
 
    if (recurLen != 0) {
      const char *afterRecur = p + recurLen;
      bool hasTrail = (*afterRecur == '.');
      const char *rest = hasTrail ? afterRecur + 1 : afterRecur;
 
      if (hasLead && hasTrail) {
        // `.**.` — match a segment boundary `.` plus zero or more
        // additional `<chars>.` segments before the boundary.
        if (*text != '.') {
          return false;
        }
        ++text;
        if (wildcardMatch(text, rest)) {
          return true;
        }
        while (*text != '\0') {
          if (*text == '.' && wildcardMatch(text + 1, rest)) {
            return true;
          }
          ++text;
        }
        return false;
      }
 
      if (hasLead) {
        // `.**` with no trailing dot: match nothing, or `.` plus any
        // suffix (including further `.`s).
        if (wildcardMatch(text, rest)) {
          return true;
        }
        if (*text != '.') {
          return false;
        }
        ++text;
        while (true) {
          if (wildcardMatch(text, rest)) {
            return true;
          }
          if (*text == '\0') {
            return false;
          }
          ++text;
        }
      }
 
      if (hasTrail) {
        // `**.` with no leading dot: match nothing, or any prefix
        // ending at a `.` (which the trailing `.` absorbs).
        if (wildcardMatch(text, rest)) {
          return true;
        }
        while (*text != '\0') {
          if (*text == '.' && wildcardMatch(text + 1, rest)) {
            return true;
          }
          ++text;
        }
        return false;
      }
 
      // Standalone `**` / `...`: match any (possibly empty) chars.
      while (true) {
        if (wildcardMatch(text, rest)) {
          return true;
        }
        if (*text == '\0') {
          return false;
        }
        ++text;
      }
    }
 
    if (*pattern == '*') {
      // Single-segment wildcard: matches zero or more non-`.` chars.
      const char *rest = pattern + 1;
      while (true) {
        if (wildcardMatch(text, rest)) {
          return true;
        }
        if (*text == '\0' || *text == '.') {
          return false;
        }
        ++text;
      }
    }
 
    if (*pattern == '?') {
      // Single character within a segment; does not match `.` or end.
      if (*text == '\0' || *text == '.') {
        return false;
      }
      ++pattern;
      ++text;
      continue;
    }
 
    if (*pattern != *text) {
      return false;
    }
    ++pattern;
    ++text;
  }
  return *text == '\0';
}
 
} // namespace slang::netlist