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MiniRobotLanguage (MRL)

 

BLO.PatternGetNth

Gets the Nth block using abstract pattern-based delimiters.

 

 

Intention

 

This Command extracts the Nth top-level block from a source string where delimiters are defined not as fixed strings, but as abstract patterns matched by the system’s WR_AW function.

It supports variable-length delimiters (1–20 characters) and uses longest-match-first logic to avoid partial matches (e.g., prefers "[**]" over "[*" when both could match).

If the end delimiter pattern is omitted, the start pattern is used for both.

 

Visual Example

 

Extracting with Pattern-Based Delimiters

 

Source String:  abc[*]&OR:[*]HELLO[*]&OR:[/*]def[*]&OR:[*]WORLD[*]&OR:[/*]xyz

                        └──────┬───────┘             └──────┬───────┘

                                │                       │

                                ▼                       ▼

Result (N=1):               "HELLO"

Result (N=2):               "WORLD"

 

 

Syntax

 

BLO.PatternGetNth|P1|P2|P3|P4|P5[|P6]

 

Parameter Explanation

 

•P1 - (Input, Text) The source string to search within.

•P2 - (Input, Text) The start delimiter pattern (e.g., "[*]&OR:[*").

•P3 - (Input, Text) The end delimiter pattern. If empty, P2 is used for both.

•P4 - (Input, Numeric) The block index to retrieve. 1 = first, -1 = last, etc.

•P5 - (Output, Variable) The variable to store the extracted block content.

•P6 - (Optional, Numeric) Maximum delimiter length to test (default = 5, max = 20).

 

Example

 

'***********************************

' BLO.PatternGetNth Example

'***********************************

$$SRC=abc[*]&OR:[*]HELLO[*]&OR:[/*]def[*]&OR:[*]WORLD[*]&OR:[/*]xyz

BLO.PatternGetNth|$$SRC|[*]&OR:[*|[*]&OR:[/*]|1|$$RES

' $$RES now contains: "HELLO"

 

' Get the last block (-1)

BLO.PatternGetNth|$$SRC|[*]&OR:[*|[*]&OR:[/*]|-1|$$LAS

' $$LAS now contains: "WORLD"

 

' Use default end delimiter (same as start)

BLO.PatternGetNth|$$SRC|[*]&OR:[*||2|$$BLO

MBX.!|$$BLO

ENR.

 

 

See also:

 

• BLO.AIGetNth - Gets Nth block using AI-resilient literal delimiters

• BLO.MultiGetNth - Gets Nth block using multiple literal delimiters