External reference parsing error

[dangerwolf]

Description

For the formula '=+'C:\corpora\EENRON_with_configs_xlsx\spreadsheets[BAM-hplr.XLS]BAM-EGS'!$BC14', the correct interpretation should be an operator '+', followed by an external reference ''C:\corpora\EENRON_with_configs_xlsx\spreadsheets[BAM-hplr.XLS]BAM-EGS'!$BC14'.

Describe the results you received:
However, after running the code, the resulting interpretation is:
"[{"TValue": "C:\corpora\EENRON_with_configs_xlsx\spreadsheets\[BAM-hplr.XLS]BAM-EGS!$BC14", "TType": "Operand", "TSubType": "Range"}]".

Describe the results you expected:
“[{"TValue": "+", "TType": "OperatorInfix", "TSubType": "Math"},{"TValue": "C:\corpora\EENRON_with_configs_xlsx\spreadsheets\[BAM-hplr.XLS]BAM-EGS!$BC14", "TType": "Operand", "TSubType": "Range"}, ]”

Output of go version:

go version go1.24.5 windows/amd64

EFP version or commit ID:

[v0.0.1](https://github.com/xuri/efp/releases/tag/v0.0.1)

Environment details (OS, physical, etc.):
windows/amd64