MiniRobotLanguage (MRL)
BLO.BlockGetFirst
Gets the first complete top-level block.
Intention
This command intelligently finds the first complete block in a string, defined by a start and end delimiter. It correctly handles nested blocks by matching the first start delimiter with its corresponding final end delimiter, ignoring any nested pairs.
This is essential for correctly parsing nested structures like HTML, XML, or bracketed text.
Syntax
BLO.BlockGetFirst|P1|P2|P3|P4
Parameter Explanation
•P1 - (Input, Text) The source string to search within.
•P2 - (Input, Text) The starting delimiter string.
•P3 - (Input, Text) The ending delimiter string.
•P4 - (Output, Text) Variable to store the resulting full block (including delimiters).
Finding the First Top-Level Block
┌─────────────────────────────────────────┐
│ │
Source String: [ITEM] Contents [SUB]Nested[/SUB] More [END] [ITEM]Second[END]
▲ ▲
│ │
Start Delimiter: ┘ │
│
End Delimiter matched, skipping the nested [SUB]...[/SUB]: ---┘
Result: "[ITEM] Contents [SUB]Nested[/SUB] More [END]"
Example
'***********************************
' BLO.BlockGetFirst Example
'***********************************
$$SRC=[START]This is the outer block with a [NESTED] block inside.[END] More text.
BLO.BlockGetFirst|$$SRC|[START]|[END]|$$RES
' $$RES correctly contains the full outer block:
' "[START]This is the outer block with a [NESTED] block inside.[END]"
MBX.$$RES
ENR.
Remarks
• This command is the foundation for parsing structured text. It returns an empty string if a complete block cannot be found.
See also:
• BLO.BlockGetFirstEx - Gets first block with extended info
• BLO.BlockGetNth - Gets the Nth top-level block