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MiniRobot Language (MRL) - MCP Memory Bank Commands
MEM.EXS / MEM.Exists
Check if a Memory Key Exists
Purpose
The MEM.EXS command checks whether a specified key exists in the MCP Memory Bank. This is useful for verifying if data has been previously stored before attempting to recall or modify it. The command returns 1 (TRUE) if the key exists, or 0 (FALSE) if it does not.
This command is particularly useful when:
• Checking if cached data is available
• Verifying if a previous computation result exists
• Avoiding errors from attempting to recall non-existent keys
• Implementing conditional logic based on memory state
Syntax
MEM.EXS|$$KEY|$$RETURN_VAR
MEM.Exists|$$KEY|$$RETURN_VAR
Parameters
$$KEY - The memory key to check for existence. This is the same key used with MEM.STO or MEM.S to store data.
$$RETURN_VAR - The variable that will receive the result (1 if key exists, 0 if not).
Return Value
1 - The key exists in the memory bank (can be recalled with MEM.RCL)
0 - The key does not exist (MEM.RCL would return empty)
Examples
' Example 1: Basic existence check
MEM.EXS|$$CachedResult|$$Exists
IVV.$$Exists!0
MEM.RCL|$$CachedResult|$$Data
PRT.Using cached data: $$Data
ELS.
PRT.No cache found, computing...
' ... compute and store result ...
EIF.
' Example 2: Check before deleting
MEM.EXS|$$TempKey|$$HasTemp
IVV.$$HasTemp!0
MEM.DEL|$$TempKey
PRT.Temporary data cleaned up
ELS.
PRT.No temporary data to clean
EIF.
' Example 3: Conditional initialization
MEM.EXS|$$Counter|$$HasCounter
IVV.$$HasCounter!0
MEM.S|$$Counter|1
PRT.Counter initialized to 1
EIF.
Remarks
The MEM.EXS command requires the Memory Bank feature to be enabled in the MCP server configuration. If the feature is disabled, the command will return 0 (FALSE) and log a warning.
The command checks for keys in the standard MCP memory store, which includes both temporary (TEMP) and permanent (PERM) storage. The persistence type does not affect the existence check.
MEM.EXS and MEM.Exists are aliases for the same command. You can use either form.
Error Conditions
The command will fail with a parameter error if:
• The key parameter is missing
• The return variable parameter is missing
• Too many parameters are provided
See also:
• MEM.STO - Store Value in Memory
• MEM.RCL - Recall Value from Memory