Files
relspecgo/pkg/sqllex/scan.go
T
warkanum 1d93255575 fix(assets): improve error reporting for asset failures
fix(embed): update embedDirectives to return result directly

fix(executor): clean up import order and formatting

fix(syntax_test): change file permission syntax to octal

fix(mysql): update file permission syntax to octal

fix(pgsql): update file permission syntax to octal

fix(sqlex): simplify Walk function parameter handling

fix(transform): adjust identifier comparison logic

fix(template): clean up function formatting and error handling
2026-10-12 22:04:40 +02:00

102 lines
2.5 KiB
Go

// Package sqllex recognizes PostgreSQL lexical boundaries without parsing SQL.
package sqllex
import "strings"
func start(c byte) bool { return c >= 128 || c == '_' || c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' }
func ident(c byte) bool { return start(c) || c >= '0' && c <= '9' || c >= 128 }
// Walk visits named parameters and standalone line comments in executable SQL. Quoted
// strings/identifiers, dollar bodies, casts and nested block comments are opaque.
// Returning replacement text is literal: it is never scanned again.
func Walk(sql string, parameter, lineComment func(string) string) string {
var out strings.Builder
for i := 0; i < len(sql); {
begin := i
switch {
case strings.HasPrefix(sql[i:], "--"):
i += 2
for i < len(sql) && sql[i] != '\n' && sql[i] != '\r' {
i++
}
text := sql[begin:i]
if lineComment != nil && strings.TrimSpace(sql[strings.LastIndexAny(sql[:begin], "\r\n")+1:begin]) == "" {
text = lineComment(text)
}
out.WriteString(text)
continue
case strings.HasPrefix(sql[i:], "/*"):
i += 2
depth := 1
for i < len(sql) && depth > 0 {
if strings.HasPrefix(sql[i:], "/*") {
depth++
i += 2
} else if strings.HasPrefix(sql[i:], "*/") {
depth--
i += 2
} else {
i++
}
}
case sql[i] == '\'' || sql[i] == '"':
q := sql[i]
escapes := q == '\'' && i > 0 && (sql[i-1] == 'E' || sql[i-1] == 'e') && (i == 1 || !ident(sql[i-2]))
i++
for i < len(sql) {
if escapes && sql[i] == '\\' {
i++
if i < len(sql) {
i++
}
continue
}
if sql[i] == q {
i++
if i < len(sql) && sql[i] == q {
i++
continue
}
break
}
i++
}
case sql[i] == '$' && (i == 0 || !ident(sql[i-1]) && sql[i-1] != '$'):
j := i + 1
if j < len(sql) && start(sql[j]) {
for j < len(sql) && ident(sql[j]) {
j++
}
}
if j < len(sql) && sql[j] == '$' {
tag := sql[i : j+1]
end := strings.Index(sql[j+1:], tag)
if end < 0 {
i = len(sql)
} else {
i = j + 1 + end + len(tag)
}
} else {
i++
}
case strings.HasPrefix(sql[i:], "::"):
i += 2
case sql[i] == ':' && i+1 < len(sql) && start(sql[i+1]) && (i == 0 || !ident(sql[i-1]) && sql[i-1] != ':'):
i += 2
for i < len(sql) && ident(sql[i]) {
i++
}
text := sql[begin:i]
if parameter != nil {
text = parameter(text)
}
out.WriteString(text)
continue
default:
i++
}
out.WriteString(sql[begin:i])
}
return out.String()
}