From 9801a7a04e44ed6c78f9f0eb0b3ecccdfc52526b Mon Sep 17 00:00:00 2001
From: Florin Iucha <florin@signbit.net>
Date: Mon, 6 Apr 2020 00:00:58 -0400
Subject: [PATCH] Preserve the indentation of external code

---
 .../antlr/net/signbit/samx/parser/SamX.g4     | 23 +++++++++++++++----
 .../signbit/samx/PrettyPrinterVisitor.java    |  9 ++++++--
 src/main/java/net/signbit/samx/Tokenize.java  |  3 +++
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/src/main/antlr/net/signbit/samx/parser/SamX.g4 b/src/main/antlr/net/signbit/samx/parser/SamX.g4
index 5d8c58d..8929ae4 100644
--- a/src/main/antlr/net/signbit/samx/parser/SamX.g4
+++ b/src/main/antlr/net/signbit/samx/parser/SamX.g4
@@ -20,7 +20,7 @@ grammar SamX;
 package net.signbit.samx.parser;
 }
 
-tokens { INDENT, DEDENT, END, INVALID }
+tokens { INDENT, DEDENT, END, INVALID, CODE_INDENT }
 
 @lexer::members 
 {
@@ -31,6 +31,9 @@ tokens { INDENT, DEDENT, END, INVALID }
    private boolean prepareProcessingCode = false;
    private boolean processingCode = false;
 
+   private int thisIndent = 0;
+   private int codeIndentBase = 0;
+
    private Token lastToken;
 
    @Override
@@ -125,6 +128,15 @@ tokens { INDENT, DEDENT, END, INVALID }
       }
    }
 
+   private void addCodeIndent()
+   {
+      CommonToken codeIndent = makeToken(SamXParser.CODE_INDENT, java.lang.Integer.toString(thisIndent - codeIndentBase));
+      codeIndent.setLine(_tokenStartLine);
+      codeIndent.setCharPositionInLine(_tokenStartCharPositionInLine);
+
+      tokens.add(codeIndent);
+   }
+
 }
 
 SKIP_
@@ -145,7 +157,7 @@ NEWLINE
    )
    {
       final char[] tokenText = getText().toCharArray();
-      int thisIndent = 0;
+      thisIndent = 0;
       for (char ch: tokenText)
       {
          if (ch == ' ')
@@ -186,6 +198,7 @@ NEWLINE
             {
                processingCode = true;
                prepareProcessingCode = false;
+               codeIndentBase = thisIndent;
             }
          }
 
@@ -265,10 +278,12 @@ flow : ( text | phrase | localInsert | url | inlineCode )+ ;
 paragraph : ( flow NEWLINE )+ NEWLINE ;
 recordRow : ( COLSEP flow )+ NEWLINE ;
 
-EXTCODE : (~'\n')+ { processingCode }?;
+EXTCODE : (~'\n')+ { processingCode }? { addCodeIndent(); };
 
 CODE_MARKER : '```(' { prepareProcessingCode = true; };
 
+externalCode : CODE_INDENT EXTCODE ;
+
 block :
      NAME TYPESEP attribute* description=flow? NEWLINE+ INDENT block+ DEDENT        # TypedBlock
    | NAME TYPESEP attribute* value=flow NEWLINE                                     # Field
@@ -280,7 +295,7 @@ block :
    | '"""[' text ']' NEWLINE ( INDENT block+ DEDENT )                               # CitationBlock
    | '>>>(' text ')' attribute*                                                     # InsertFragment
    | '<<<(' text ')' attribute*                                                     # IncludeFile
-   | CODE_MARKER language=text ')' attribute* NEWLINE+ INDENT (EXTCODE? NEWLINE)+ DEDENT     # CodeBlock
+   | CODE_MARKER language=text ')' attribute* NEWLINE+ INDENT (externalCode? NEWLINE)+ DEDENT     # CodeBlock
    | NEWLINE                                                                        # Empty
    ;
 
diff --git a/src/main/java/net/signbit/samx/PrettyPrinterVisitor.java b/src/main/java/net/signbit/samx/PrettyPrinterVisitor.java
index e5c08d8..70eeee7 100644
--- a/src/main/java/net/signbit/samx/PrettyPrinterVisitor.java
+++ b/src/main/java/net/signbit/samx/PrettyPrinterVisitor.java
@@ -362,10 +362,15 @@ public StringBuilder visitCodeBlock(SamXParser.CodeBlockContext ctx)
       builder.append('\n');
 
       indentLevel ++;
-      for (TerminalNode tn: ctx.EXTCODE())
+      for (SamXParser.ExternalCodeContext ecc: ctx.externalCode())
       {
          addIndent(builder);
-         builder.append(tn.getText());
+         int codeIndent = Integer.valueOf(ecc.CODE_INDENT().getText());
+         for (int ii = 0; ii < codeIndent; ++ii)
+         {
+            builder.append(' ');
+         }
+         builder.append(ecc.EXTCODE().getText());
          builder.append('\n');
       }
       indentLevel --;
diff --git a/src/main/java/net/signbit/samx/Tokenize.java b/src/main/java/net/signbit/samx/Tokenize.java
index efc5bbb..883cc61 100644
--- a/src/main/java/net/signbit/samx/Tokenize.java
+++ b/src/main/java/net/signbit/samx/Tokenize.java
@@ -67,6 +67,9 @@ public static void main(String[] args)
                   case SamXParser.INVALID:
                      tokenSymbol = "INVALID";
                      break;
+                  case SamXParser.CODE_INDENT:
+                     tokenSymbol = "CODE_IDT";
+                     break;
                   default:
                      tokenSymbol = "¯\\_(ツ)_/¯";
                      break;