Remove Guava dependency by replicating minimal case format transformation

Author: ZackPierce

build.gradle

@@ -165,7 +165,6 @@ def validationXsdPath = project(':sbe-tool').projectDir.toString() + '/src/main/
 project(':sbe-tool') {
  dependencies {
  compile 'org.agrona:agrona:0.9.6'
- compile 'com.google.guava:guava:21.0'
 
  testCompile files('build/classes/java/generated')
  }

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/rust/RustUtil.java

@@ -1,6 +1,5 @@
 package uk.co.real_logic.sbe.generation.rust;
 
-import com.google.common.base.CaseFormat;
 import org.agrona.Verify;
 import uk.co.real_logic.sbe.PrimitiveType;
 
@@ -96,8 +95,54 @@ static String formatMethodName(final String value)
  {
  return value;
  }
- final String fromUpper = toLowerFirstChar(value);
- return sanitizeMethodOrProperty(CaseFormat.LOWER_CAMEL.to(CaseFormat.LOWER_UNDERSCORE, fromUpper));
+ return sanitizeMethodOrProperty(toLowerUnderscoreFromCamel(value));
+ }
+
+ // Adapted from Guava, Apache License Version 2.0
+ private static String toLowerUnderscoreFromCamel(final String value)
+ {
+ if (value.isEmpty())
+ {
+ return value;
+ }
+ final String s = toLowerFirstChar(value);
+
+ // include some extra space for separators
+ final StringBuilder out = new StringBuilder(s.length() + 4);
+ int i = 0;
+ int j = -1;
+ while ((j = indexInUpperAlphaRange(s, ++j)) != -1)
+ {
+ final String word = s.substring(i, j).toLowerCase();
+ out.append(word);
+ if (!word.endsWith("_"))
+ {
+ out.append("_");
+ }
+ i = j;
+ }
+ return (i == 0)
+ ? s.toLowerCase()
+ : out.append(s.substring(i).toLowerCase()).toString();
+ }
+
+ // Adapted from Guava, Apache License Version 2.0
+ private static int indexInUpperAlphaRange(final CharSequence sequence, final int start)
+ {
+ final int length = sequence.length();
+ if (start < 0 || start > length)
+ {
+ throw new IndexOutOfBoundsException();
+ }
+ for (int i = start; i < length; i++)
+ {
+ final char c = sequence.charAt(i);
+ if ('A' <= c && c <= 'Z')
+ {
+ return i;
+ }
+ }
+ return -1;
  }
 
  private static String sanitizeMethodOrProperty(final String name)

sbe-tool/src/test/java/uk/co/real_logic/sbe/generation/rust/RustUtilTest.java

@@ -4,6 +4,7 @@
 import uk.co.real_logic.sbe.PrimitiveType;
 
 import static org.junit.Assert.assertEquals;
+import static uk.co.real_logic.sbe.generation.rust.RustUtil.formatMethodName;
 import static uk.co.real_logic.sbe.generation.rust.RustUtil.generateRustLiteral;
 
 public class RustUtilTest
@@ -63,4 +64,20 @@ public void generateRustLiteralNullValueParam()
  {
  generateRustLiteral(PrimitiveType.INT8, null);
  }
+
+ @Test
+ public void methodNameCasing()
+ {
+ assertEquals("", formatMethodName(""));
+ assertEquals("a", formatMethodName("a"));
+ assertEquals("a", formatMethodName("A"));
+ assertEquals("car", formatMethodName("Car"));
+ assertEquals("car", formatMethodName("car"));
+ assertEquals("decode_car", formatMethodName("DecodeCar"));
+ assertEquals("decode_car", formatMethodName("decodeCar"));
+ assertEquals("decode_car", formatMethodName("decode_car"));
+ assertEquals("decode_car", formatMethodName("Decode_car"));
+ assertEquals("decode_car", formatMethodName("decode_Car"));
+ assertEquals("decode_car", formatMethodName("Decode_Car"));
+ }
 }