chrislu 179a7b446e feat: Add comprehensive string functions with extensive tests ...

Implemented String Functions:
- LENGTH: Get string length (supports all value types)
- UPPER/LOWER: Case conversion
- TRIM/LTRIM/RTRIM: Whitespace removal (space, tab, newline, carriage return)
- SUBSTRING: Extract substring with optional length (SQL 1-based indexing)
- CONCAT: Concatenate multiple values (supports mixed types, skips nulls)
- REPLACE: Replace all occurrences of substring
- POSITION: Find substring position (1-based, 0 if not found)
- LEFT/RIGHT: Extract leftmost/rightmost characters
- REVERSE: Reverse string with proper Unicode support

Key Features:
- Robust type conversion (string, int, float, bool, bytes)
- Unicode-safe operations (proper rune handling in REVERSE)
- SQL-compatible indexing (1-based for SUBSTRING, POSITION)
- Comprehensive error handling with descriptive messages
- Mixed-type support (e.g., CONCAT number with string)

Helper Functions:
- valueToString: Convert any schema_pb.Value to string
- valueToInt64: Convert numeric values to int64

Comprehensive test suite with 25+ test cases covering:
- All string functions with typical use cases
- Type conversion scenarios (numbers, booleans)
- Edge cases (empty strings, null values, Unicode)
- Error conditions and boundary testing

All tests passing ✅

2025-09-04 00:21:17 -07:00

..

engine

feat: Add comprehensive string functions with extensive tests

2025-09-04 00:21:17 -07:00

json

move to https://github.com/seaweedfs/seaweedfs

2022-07-29 00:17:28 -07:00

sqltypes

go fmt

2019-10-09 00:03:18 -07:00