Add support for new lines in Sequence (#40)

* Add support for new lines in Sequence

When using `diagon Sequence` it is not possible (at least I couldn't
find a way) to add new lines to the messages in the Sequence submodule.

This patch adds parameter `--new_lines_at_bsn` that results in
substituting literal `\n` with new lines.

Example:

```bash
$ echo "Alice -> Bob: send(\n  msg="Hello...",\n  length=8,\n)" | \
       diagon Sequence --new_lines_at_bsn=true
```

output:
```
┌─────┐          ┌───┐
│Alice│          │Bob│
└──┬──┘          └─┬─┘
   │               │
   │send(          │
   │  msg=Hello...,│
   │  length=8,    │
   │)              │
   │──────────────>│
┌──┴──┐          ┌─┴─┐
│Alice│          │Bob│
└─────┘          └───┘
```

* Add tests & refactor.

Co-authored-by: ArthurSonzogni <sonzogniarthur@gmail.com>

src/translator/sequence/Sequence.cpp

@@ -14,6 +14,23 @@
 #include "translator/antlr_error_listener.h"
 #include "translator/sequence/Graph.hpp"
 
+namespace {
+
+void SplitString(std::wstring input,
+                 const std::wstring& delimiter,
+                 std::vector<std::wstring>* out) {
+  size_t start = 0U;
+  size_t end = input.find(delimiter);
+  while (end != std::wstring::npos) {
+    out->push_back(input.substr(start, end - start));
+    start = end + delimiter.length();
+    end = input.find(delimiter, start);
+  }
+  out->push_back(input.substr(start));
+}
+
+}  // namespace
+
 void Actor::Draw(Screen& screen, int height) {
   screen.DrawBoxedText(left, 0, name);
   screen.DrawVerticalLine(3, height - 4, center);
@@ -211,6 +228,17 @@ std::vector<Translator::OptionDescription> Sequence::Options() {
           "Use the full unicode charset or only ASCII.",
           Widget::Checkbox,
       },
+      {
+          "interpret_backslash_n",
+          {
+              "false",
+              "true",
+          },
+          "true",
+          "Insert new lines at every occurence of '\\n' (backslash n) in the "
+          "message field.",
+          Widget::Checkbox,
+      },
   };
 }
 
@@ -254,13 +282,27 @@ std::string Sequence::Translate(const std::string& input,
 
   auto options = SerializeOption(options_string);
   ascii_only_ = (options["ascii_only"] == "true");
+  interpret_backslash_n_ = (options["interpret_backslash_n"] == "true");
 
   ComputeInternalRepresentation(input);
   UniformizeInternalRepresentation();
+  SplitByBackslashN();
   Layout();
   return Draw();
 }
 
+void Sequence::SplitByBackslashN() {
+  if (!interpret_backslash_n_) {
+    return;
+  }
+  for (auto& message : messages) {
+    std::vector<std::wstring> old = std::move(message.messages);
+    for(auto& it : old) {
+      SplitString(it, L"\\n", &message.messages);
+    }
+  }
+}
+
 void Sequence::ComputeInternalRepresentation(const std::string& input) {
   antlr4::ANTLRInputStream input_stream(input);
 

src/translator/sequence/Sequence.hpp

@@ -100,6 +100,8 @@ class Sequence : public Translator {
   void UniformizeActors();
   void UniformizeMessageID();
 
+  void SplitByBackslashN();
+
   // 3) Layout.
   void Layout();
   void LayoutComputeMessageWidth();
@@ -125,4 +127,5 @@ class Sequence : public Translator {
   std::map<int, int> message_index;
 
   bool ascii_only_;
+  bool interpret_backslash_n_ = false;
 };

test/Sequence/multiline/input

@@ -0,0 +1,3 @@
+A -> B: This is a\nmultiline string.
+A -> B: This is another\nmultiline string.
+B -> A: This is the \nlast one.

test/Sequence/multiline/output

@@ -0,0 +1,18 @@
+┌─┐               ┌─┐
+│A│               │B│
+└┬┘               └┬┘
+ │                 │ 
+ │This is a        │ 
+ │multiline string.│ 
+ │────────────────>│ 
+ │                 │ 
+ │This is another  │ 
+ │multiline string.│ 
+ │────────────────>│ 
+ │                 │ 
+ │  This is the    │ 
+ │  last one.      │ 
+ │<────────────────│ 
+┌┴┐               ┌┴┐
+│A│               │B│
+└─┘               └─┘

test/Sequence/multiline_interleaved/input

@@ -0,0 +1,5 @@
+1) A -> B : message\nnumber\n1
+2) A -> B : message\nnumber\n2
+
+A: 1<2
+B: 1>2

test/Sequence/multiline_interleaved/output

@@ -0,0 +1,17 @@
+┌─┐     ┌─┐
+│A│     │B│
+└┬┘     └┬┘
+ │       │ 
+ │──┐    │ 
+ │message│ 
+ │number │ 
+ │2 │    │ 
+ │──────>│ 
+ │  │    │ 
+ │message│ 
+ │number │ 
+ │1 │    │ 
+ │  └───>│ 
+┌┴┐     ┌┴┐
+│A│     │B│
+└─┘     └─┘

test/Sequence/multiline_interleaved_mixed/input

@@ -0,0 +1,5 @@
+1) A -> B : message number 1
+2) A -> B : message\nnumber\n2
+
+A: 1<2
+B: 1>2

test/Sequence/multiline_interleaved_mixed/output

@@ -0,0 +1,15 @@
+┌─┐              ┌─┐
+│A│              │B│
+└┬┘              └┬┘
+ │                │ 
+ │──┐             │ 
+ │  │ message     │ 
+ │  │ number      │ 
+ │  │ 2           │ 
+ │───────────────>│ 
+ │  │             │ 
+ │message number 1│ 
+ │  └────────────>│ 
+┌┴┐              ┌┴┐
+│A│              │B│
+└─┘              └─┘

test/Sequence/multiline_interleaved_mixed_2/input

@@ -0,0 +1,5 @@
+1) A -> B : message\nnumber\n1
+2) A -> B : message number 2
+
+A: 1<2
+B: 1>2

test/Sequence/multiline_interleaved_mixed_2/output

@@ -0,0 +1,15 @@
+┌─┐              ┌─┐
+│A│              │B│
+└┬┘              └┬┘
+ │                │ 
+ │──┐             │ 
+ │message number 2│ 
+ │───────────────>│ 
+ │  │             │ 
+ │  │ message     │ 
+ │  │ number      │ 
+ │  │ 1           │ 
+ │  └────────────>│ 
+┌┴┐              ┌┴┐
+│A│              │B│
+└─┘              └─┘