snapshot of https://github.com/sqlc-dev/sqlc.git (main, 2026-09-16; blobs > 131072B omitted)

internal/pattern/match.go

@@ -0,0 +1,86 @@
+package pattern
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+	"sync"
+)
+
+// Match is a wrapper of *regexp.Regexp.
+// It contains the match pattern compiled into a regular expression.
+type Match struct {
+	*regexp.Regexp
+}
+
+var (
+	matchCache     = make(map[string]*Match)
+	matchCacheLock sync.RWMutex
+)
+
+// Compile takes our match expression as a string, and compiles it into a *Match object.
+// Will return an error on an invalid pattern.
+func MatchCompile(pattern string) (*Match, error) {
+	// check for pattern in cache
+	matchCacheLock.RLock()
+	matcher, ok := matchCache[pattern]
+	matchCacheLock.RUnlock()
+	if ok {
+		return matcher, nil
+	}
+
+	// pattern isn't in cache, compile it
+	matcher, err := matchCompile(pattern)
+	if err != nil {
+		return nil, err
+	}
+	// add it to the cache
+	matchCacheLock.Lock()
+	matchCache[pattern] = matcher
+	matchCacheLock.Unlock()
+
+	return matcher, nil
+}
+
+func matchCompile(pattern string) (match *Match, err error) {
+	var regex strings.Builder
+	escaped := false
+	arr := []byte(pattern)
+
+	for i := range arr {
+		if escaped {
+			escaped = false
+			switch arr[i] {
+			case '*', '?', '\\':
+				regex.WriteString("\\" + string(arr[i]))
+			default:
+				return nil, fmt.Errorf("Invalid escaped character '%c'", arr[i])
+			}
+		} else {
+			switch arr[i] {
+			case '\\':
+				escaped = true
+			case '*':
+				regex.WriteString(".*")
+			case '?':
+				regex.WriteString(".")
+			case '.', '(', ')', '+', '|', '^', '$', '[', ']', '{', '}':
+				regex.WriteString("\\" + string(arr[i]))
+			default:
+				regex.WriteString(string(arr[i]))
+			}
+		}
+	}
+
+	if escaped {
+		return nil, fmt.Errorf("Unterminated escape at end of pattern")
+	}
+
+	var r *regexp.Regexp
+
+	if r, err = regexp.Compile("^" + regex.String() + "$"); err != nil {
+		return nil, err
+	}
+
+	return &Match{r}, nil
+}