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Overview

Field helper functions provide a convenient and type-safe way to create structured log fields. These functions are zero-allocation and designed for efficient logging.

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String

Creates a Field with a string value. This is the most common field type for log messages. 
func String(key, val string) Field
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key
string
required
The field key
​
val
string
required
The string value
Returns: A Field with type StringType.

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Example

logger.Info("User logged in",
    go_logs.String("username", "john"),
    go_logs.String("ip", "192.168.1.1"))

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Int

Creates a Field with an int value. Useful for numeric data like counts, IDs, ports, etc. 
func Int(key string, val int) Field
​
key
string
required
The field key
​
val
int
required
The integer value
Returns: A Field with type IntType.

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Example

logger.Info("Request processed",
    go_logs.Int("status_code", 200),
    go_logs.Int("response_time_ms", 45))

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Int64

Creates a Field with an int64 value. Use this for large integers or when you need explicit 64-bit precision. 
func Int64(key string, val int64) Field
​
key
string
required
The field key
​
val
int64
required
The int64 value
Returns: A Field with type Int64Type.

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Example

logger.Info("File size",
    go_logs.Int64("bytes", 1536299520))

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Float64

Creates a Field with a float64 value. Useful for measurements, percentages, etc. 
func Float64(key string, val float64) Field
​
key
string
required
The field key
​
val
float64
required
The float64 value
Returns: A Field with type Float64Type.

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Example

logger.Info("Memory usage",
    go_logs.Float64("cpu_percent", 45.7),
    go_logs.Float64("memory_gb", 1.23))

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Bool

Creates a Field with a bool value. Useful for flags and boolean state. 
func Bool(key string, val bool) Field
​
key
string
required
The field key
​
val
bool
required
The boolean value
Returns: A Field with type BoolType.

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Example

logger.Info("Feature flags",
    go_logs.Bool("debug_mode", true),
    go_logs.Bool("cache_enabled", false))

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Err

Creates a Field with an error value. The key is automatically set to “error” for consistency. Errors are formatted specially by formatters. 
func Err(err error) Field
​
err
error
required
The error value
Returns: A Field with type ErrorType and key “error”.

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Example

logger.Error("Database connection failed",
    go_logs.Err(err),
    go_logs.String("host", "localhost"))

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Any

Creates a Field with an arbitrary value. Use this when the type doesn’t match the typed helpers. The formatter will use fmt.Sprintf("%v") to format the value. 
func Any(key string, val interface{}) Field
​
key
string
required
The field key
​
val
interface{}
required
The value of any type
Returns: A Field with type AnyType.

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Example

type User struct {
    Name string
    Age  int
}

logger.Info("Complex data",
    go_logs.Any("user", User{Name: "John", Age: 30}))

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Performance

All field helper functions are designed for zero allocations and optimal performance:
  • Field creation: ~0.34 ns/op with 0 allocations
  • Zero-allocation design: Fields are simple structs passed by value
  • Type safety: Compile-time type checking for field values

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Best Practices

  1. Use typed helpers: Prefer String(), Int(), etc. over Any() for better performance and type safety
  2. Consistent naming: Use snake_case for field keys (e.g., user_id, request_id)
  3. Error handling: Always use Err() for error values to ensure consistent formatting
  4. Avoid sensitive data: Don’t log passwords, tokens, or other secrets in field values

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