Fix issue with blank string characters

iamgio · Aug 1, 2023 · 0538b86 · 0538b86
1 parent 5e034e1
commit 0538b86
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Showing 3 changed files with 15 additions and 2 deletions.
diff --git a/core/src/main/kotlin/eu/iamgio/pikt/expression/ExpressionParser.kt b/core/src/main/kotlin/eu/iamgio/pikt/expression/ExpressionParser.kt
@@ -141,8 +141,13 @@ class ExpressionParser(
                 if (!requireNumber || characterPixel.isNumber || (characterPixel.characterContent == '-' && components.isEmpty())) {
                     // Grayscale pixel -> character, except for null character (code 0)
                     // Therefore, the null character is useful to force string initialization or concatenation.
-                    characterPixel.characterContent.takeIf { it.code != 0 }
-                        ?.let { components += StringCharacter(it) }
+                    characterPixel.characterContent.let { char ->
+                        components += if (char.code != 0) {
+                            StringCharacter(char)
+                        } else {
+                            StringBlankCharacter
+                        }
+                    }
                 } else {
                     reader.error("Member not expected while parsing number.")
                 }

diff --git a/core/src/main/kotlin/eu/iamgio/pikt/expression/StringExpression.kt b/core/src/main/kotlin/eu/iamgio/pikt/expression/StringExpression.kt
@@ -15,6 +15,12 @@ data class StringCharacter(val character: Char) : StringComponent
  */
 data class StringReference(val sequence: PixelSequence) : StringComponent
 
+/**
+ * An empty character that serves no purpose to the content of a string,
+ * but may be useful to force a string initialization or to initialize an empty string.
+ */
+object StringBlankCharacter : StringComponent
+
 /**
  * Expression that wraps a string value.
  *

diff --git a/core/src/main/kotlin/eu/iamgio/pikt/expression/kotlin/KotlinExpressionTranspiler.kt b/core/src/main/kotlin/eu/iamgio/pikt/expression/kotlin/KotlinExpressionTranspiler.kt
@@ -10,13 +10,15 @@ class KotlinExpressionTranspiler(private val scope: Scope) : ExpressionTranspile
         when (it) {
             is StringCharacter -> it.character.toString()
             is StringReference -> "\${${sequence(it.sequence)}}"
+            is StringBlankCharacter -> ""
         }
     } + "\""
 
     override fun number(expression: StringExpression) = expression.components.joinToString("") {
         when (it) {
             is StringCharacter -> it.character.toString()
             is StringReference -> "" // TODO maybe interpet it as a sum between variables?
+            is StringBlankCharacter -> ""
         }
     }