From 2c9a3f7cbda8e70a7468524d8aed71374a71cb9f Mon Sep 17 00:00:00 2001
From: Karol Stasiak <karol.m.stasiak@gmail.com>
Date: Fri, 31 Jul 2020 13:31:07 +0200
Subject: [PATCH] Add ENCODING_NOLOWER

---
 docs/lang/preprocessor.md                      |  2 ++
 src/main/scala/millfork/Platform.scala         |  1 +
 src/main/scala/millfork/parser/TextCodec.scala | 11 +++++++++++
 3 files changed, 14 insertions(+)

diff --git a/docs/lang/preprocessor.md b/docs/lang/preprocessor.md
index 66154206..d6711ff4 100644
--- a/docs/lang/preprocessor.md
+++ b/docs/lang/preprocessor.md
@@ -58,6 +58,8 @@ The following features are defined based on the chosen CPU and compilation optio
 
 * `ENCODING_SAME` - 1 if the encodings `default` and `src` are the same, 0 otherwise.
 
+* `ENCODING_NOLOWER` – 1 if the `default` encoding does not support lowercase ASCII letters.
+
 * `DECIMALS_SAME` - 1 if the encodings `default` and `src` have the same string terminator and decimal digits `'0'`-`'9'`, 0 otherwise.
 
 * `NULLCHAR_SAME` - 1 if the encodings `default` and `src` have the same string terminator, 0 otherwise.
diff --git a/src/main/scala/millfork/Platform.scala b/src/main/scala/millfork/Platform.scala
index 4a8d670f..163d29b7 100644
--- a/src/main/scala/millfork/Platform.scala
+++ b/src/main/scala/millfork/Platform.scala
@@ -318,6 +318,7 @@ object Platform {
       log.fatal(s"Invalid label file format: `$debugOutputFormatName`"))
 
     val builtInFeatures = builtInCpuFeatures(cpu) ++ Map(
+      "ENCODING_NOLOWER" -> toLong(codec.supportsLowercase),
       "ENCODING_SAME" -> toLong(codec.name == srcCodec.name),
       "DECIMALS_SAME" -> toLong(codec.stringTerminator == srcCodec.stringTerminator && (0 to 9).forall{c =>
         codec.encodeDigit(c) == srcCodec.encodeDigit(c)
diff --git a/src/main/scala/millfork/parser/TextCodec.scala b/src/main/scala/millfork/parser/TextCodec.scala
index ab0d1729..e37dc008 100644
--- a/src/main/scala/millfork/parser/TextCodec.scala
+++ b/src/main/scala/millfork/parser/TextCodec.scala
@@ -15,6 +15,8 @@ import millfork.node.Position
 final case class TextCodecWithFlags(codec: TextCodec, nullTerminated: Boolean, lengthPrefixed: Boolean, lenient: Boolean)
 
 sealed trait TextCodec {
+  val supportsLowercase: Boolean
+
   def name: String
 
   def stringTerminator: List[Int]
@@ -126,6 +128,8 @@ class UnicodeTextCodec(override val name: String, val charset: Charset, override
     else if (by == 0) '.'
     else '?'
   }
+
+  override val supportsLowercase: Boolean = true
 }
 
 class TableTextCodec(override val name: String,
@@ -180,6 +184,11 @@ class TableTextCodec(override val name: String,
     if (codePoints.forall(isPrintable)) f"`$s%s` ($u%s)"
     else u
   }
+
+  private def supportsChar(c: Char): Boolean = {
+    decompositions.contains(c) || directDecompositions.contains(c) || map.indexOf(c) >= 0
+  }
+
   private def encodeChar(log: Logger, position: Option[Position], c: Char, options: CompilationOptions, lenient: Boolean): Option[List[Int]] = {
       if (decompositions.contains(c)) {
         Some(decompositions(c).toList.flatMap(x => encodeChar(log, position, x, options, lenient).getOrElse(List(x.toInt))))
@@ -271,6 +280,8 @@ class TableTextCodec(override val name: String,
     if (i < 0) throw new IllegalStateException(s"For some reason, there is no digit $digit in the $name encoding?")
     List(i)
   }
+
+  override val supportsLowercase: Boolean = 'a' to 'z' forall(c => supportsChar(c))
 }
 
 object TextCodec {