[Refactor] Organize syntax highlighting rules into separate initialization functions for better readability and maintainability

Author: chrisdedman

src/Syntax.cpp

@@ -1,49 +1,95 @@
 #include "Syntax.h"
+#include <QColor>
+#include <QFont>
 
-Syntax::Syntax(QTextDocument *parent) : QSyntaxHighlighter(parent)
+Syntax::Syntax(QTextDocument *parent)
+    : QSyntaxHighlighter(parent)
 {
-  keywordFormat.setForeground(Qt::blue);
-  keywordFormat.setFontWeight(QFont::Bold);
-  QStringList keywordPatterns;
-  keywordPatterns << "\\bchar\\b" << "\\bclass\\b" << "\\bconst\\b"
-                  << "\\bdouble\\b" << "\\benum\\b" << "\\bexplicit\\b"
-                  << "\\bfriend\\b" << "\\binline\\b" << "\\bint\\b"
-                  << "\\blong\\b" << "\\bnamespace\\b" << "\\boperator\\b"
-                  << "\\bprivate\\b" << "\\bprotected\\b" << "\\bpublic\\b"
-                  << "\\bshort\\b" << "\\bsignals\\b" << "\\bsigned\\b"
-                  << "\\bslots\\b" << "\\bstatic\\b" << "\\bstruct\\b"
-                  << "\\btemplate\\b" << "\\btypedef\\b" << "\\btypename\\b"
-                  << "\\bunion\\b" << "\\bunsigned\\b" << "\\bvirtual\\b"
-                  << "\\bvoid\\b" << "\\bvolatile\\b" << "\\bforeach\\b";
-  foreach (const QString &pattern, keywordPatterns)
-  {
-    addPattern(pattern, keywordFormat);
-  }
+    initKeywordRules();
+    initFunctionRules();
+    initParenthesisRules();
+    initCharRules();
 
-  // Single line comment format expression
-  singleLineCommentFormat.setForeground(Qt::darkGray);
-  addPattern("//[^\n]*", singleLineCommentFormat);
+    // Keep these two calls are at the end
+    // to correctly apply the rules for strings and comments
+    initCommentRules();
+    initQuotationRules();
+}
+
+void Syntax::initKeywordRules()
+{
+    // Keyword format
+    keywordFormat.setForeground(Qt::blue);
+    keywordFormat.setFontWeight(QFont::Bold);
+
+    QStringList keywordPatterns = {
+        "\\bchar\\b", "\\bclass\\b", "\\bconst\\b",
+        "\\bdouble\\b", "\\benum\\b", "\\bexplicit\\b",
+        "\\bfriend\\b", "\\binline\\b", "\\bint\\b",
+        "\\blong\\b", "\\bnamespace\\b", "\\boperator\\b",
+        "\\bprivate\\b", "\\bprotected\\b", "\\bpublic\\b",
+        "\\bshort\\b", "\\bsignals\\b", "\\bsigned\\b",
+        "\\bslots\\b", "\\bstatic\\b", "\\bstruct\\b",
+        "\\btemplate\\b", "\\btypedef\\b", "\\btypename\\b",
+        "\\bunion\\b", "\\bunsigned\\b", "\\bvirtual\\b",
+        "\\bvoid\\b", "\\bvolatile\\b", "\\bforeach\\b"};
+
+    for (const QString &pattern : keywordPatterns)
+    {
+        addPattern(pattern, keywordFormat);
+    }
 
-  // Double quotation mark for string
-  quotationMark.setForeground(Qt::darkGreen);
-  addPattern("\".*\"", quotationMark);
+    iterationFormat.setForeground(Qt::darkMagenta);
+    iterationFormat.setFontWeight(QFont::Bold);
+    QStringList iterationPatterns = {
+        "\\bfor\\b", "\\bwhile\\b", "\\bdo\\b", "\\bif\\b", "\\belse\\b"};
+    for (const QString &pattern : iterationPatterns)
+    {
+        addPattern(pattern, iterationFormat);
+    }
+}
 
-  // Function format expression
-  functionFormat.setFontItalic(true);
-  functionFormat.setForeground(Qt::darkYellow);
-  addPattern("\\b[a-zA-Z_][a-zA-Z0-9_]*(?=\\s*\\()", functionFormat);
+void Syntax::initCommentRules()
+{
+    // Single line comment format expression
+    singleLineCommentFormat.setForeground(Qt::darkGray);
+    addPattern("//[^\n]*", singleLineCommentFormat);
 
-  // Color pattern for parenthesis
-  QColor parenthesisColor("#6495ED");
-  parenthesisFormat.setForeground(parenthesisColor);
-  addPattern("[()]", parenthesisFormat);
+    // TO-DO: Add multi-line comment support
+}
 
-  // Regex for single character format 'a', '\n', etc
-  charFormat.setForeground(Qt::darkCyan);
-  addPattern("'(\\\\.|[^'])'", charFormat);
+void Syntax::initQuotationRules()
+{
+    // Double quotation mark for string
+    quotationMark.setForeground(Qt::darkGreen);
+    addPattern("\"(\\\\.|[^\"\\\\])*\"", quotationMark);
+
+    //  TO-DO: Add single quotation mark for character
+}
+
+void Syntax::initFunctionRules()
+{
+    // Function format expression
+    functionFormat.setFontItalic(true);
+    functionFormat.setForeground(Qt::darkYellow);
+    addPattern("\\b(?!for\\b|if\\b|else\\b|while\\b|do\\b)[a-zA-Z_][a-zA-Z0-9_]*(?=\\s*\\()", functionFormat);
+}
+
+void Syntax::initParenthesisRules()
+{
+    // Color pattern for parenthesis
+    QColor parenthesisColor("#6495ED");
+    parenthesisFormat.setForeground(parenthesisColor);
+    addPattern("[()]", parenthesisFormat);
+}
+
+// Regex for single character format 'a', '\n', etc.
+void Syntax::initCharRules()
+{
+    charFormat.setForeground(Qt::darkCyan);
+    addPattern("'(\\\\.|[^'])'", charFormat);
 }
 
-// Add syntax highlighting patterns
 void Syntax::addPattern(const QString &pattern, const QTextCharFormat &format)
 {
     SyntaxRule rule;
@@ -54,13 +100,13 @@ void Syntax::addPattern(const QString &pattern, const QTextCharFormat &format)
 
 void Syntax::highlightBlock(const QString &text)
 {
-  foreach (const SyntaxRule &rule, syntaxRules)
-  {
-    QRegularExpressionMatchIterator matchIterator = rule.pattern.globalMatch(text);
-    while (matchIterator.hasNext())
+    for (const SyntaxRule &rule : syntaxRules)
     {
-      QRegularExpressionMatch match = matchIterator.next();
-      setFormat(match.capturedStart(), match.capturedLength(), rule.format);
+        QRegularExpressionMatchIterator matchIterator = rule.pattern.globalMatch(text);
+        while (matchIterator.hasNext())
+        {
+            QRegularExpressionMatch match = matchIterator.next();
+            setFormat(match.capturedStart(), match.capturedLength(), rule.format);
+        }
     }
-  }
 }