%% Regex Parsing and Match Result Comparison Process
flowchart TD
Start["🔹 Start"] --> Step1_1["1.1 Split regex structure
（Using a special regular expression to match the target regex, decompose it into the following structures with a ratio of 1:1:1:1+:
▫️Prefix: Actual matching characters, anchors, group construct prefixes [(, (?>, (?=, etc.], inline comments, closing parenthesis ')','|'
▫️Quantifier 1: Basic quantifiers such as +, *, ?, {num1,num2}
▫️Quantifier 2: Lazy matching symbol '?'
▫️Comment: Inline comments, end-of-line comments, invalid whitespace (at least one empty comment as a separator)
"]
Step1_1 --> Step1_2["1.2 Parse into custom syntax tree
（Traverse all decomposed structures to generate a structured syntax tree）
The following actions may be performed:
▫️Simplify quantifiers
▫️Move quantifiers after ignored whitespace, inline comments, and end-of-line comments
▫️Simplify redundant '|' in conditional expressions
▫️Cross-platform compatible conversion (Reference:
Cross-platform compatibility issue)
"]
Step1_2 --> Step_input{"Is there input to match?"}
Step_input --> |Yes| Step2["2. Initialize input subscript
（Set txtpos = 0）"]
Step_input --> |No| Step9["9. Return compressed results"]
Step2 --> Step3["3. Infer new matches
（Start matching from txtpos）"]
Step3 --> Step4{"4. Match successful?"}
Step4 -->|Yes| Step5["5. Compare results with C# output
(Check Index and Length of all the captures of all groups)
(
Why need two validation modes? Because sometimes the outputs of the two modes are inconsistent)"]
Step5 --> Step6{"6. Is the current match length 0?"}
Step6 -->|Yes| Step6a["txtpos += 1
（Avoid infinite loops）"]
Step6 -->|No| Step6b["txtpos = end position of the current match"]
Step6a & Step6b --> Step7{"7. txtpos > input.Length?"}
Step7 -->|No| Step3
Step7 -->|Yes| Step8["8. Consistency check of the number of matches
（Compare the number of inferred matches with C# output, mark if inconsistent）"]
Step4 -->|Failure| Step8
Step8 --> Step9
Step9 --> End["🔹 End"]
%% Style definitions (consistent with the original example)
classDef startEnd fill:#f0f8ff,stroke:#1976d2,stroke-width:2px,rounded:10px
classDef process fill:#e8f5e9,stroke:#388e3c,stroke-width:1.5px,rounded:5px
classDef decision fill:#fff3e0,stroke:#f57c00,stroke-width:1.5px,diamond:true
%% Style binding (consistent with the original example)
class Start,End startEnd
class Step1_1,Step1_2,Step2,Step3,Step5,Step6a,Step6b,Step8,Step9 process
class Step_input,Step4,Step6,Step7 decision