diff --git a/src/aztec/encoder/state.rs b/src/aztec/encoder/state.rs
index a6333ab..d072ea6 100644
--- a/src/aztec/encoder/state.rs
+++ b/src/aztec/encoder/state.rs
@@ -76,9 +76,9 @@ impl State {
         let result = self.shiftAndAppend(HighLevelEncoder::MODE_PUNCT as u32, 0); // 0: FLG(n)
         let mut token = result.token;
         let mut bits_added = 3;
-        if eci < 0 {
+        /*if eci < 0 {
             token.add(0, 3); // 0: FNC1
-        } else if eci > 999999 {
+        } else */if eci > 999999 {
             return Err(Exceptions::IllegalArgumentException(
                 "ECI code must be between 0 and 999999".to_owned(),
             ));
diff --git a/src/client/result/ResultParser.rs b/src/client/result/ResultParser.rs
index 35da8a4..ed79f6e 100644
--- a/src/client/result/ResultParser.rs
+++ b/src/client/result/ResultParser.rs
@@ -239,7 +239,7 @@ pub fn isStringOfDigits(value: &str, length: usize) -> bool {
 }
 
 pub fn isSubstringOfDigits(value: &str, offset: usize, length: usize) -> bool {
-    if value.is_empty() || length <= 0 {
+    if value.is_empty() || length == 0 {
         return false;
     }
     let max = offset as usize + length;
diff --git a/src/client/result/VCardResultParser.rs b/src/client/result/VCardResultParser.rs
index 1985452..a3c4767 100644
--- a/src/client/result/VCardResultParser.rs
+++ b/src/client/result/VCardResultParser.rs
@@ -173,8 +173,8 @@ pub fn matchVCardPrefixedField(
     parseFieldDivider: bool,
 ) -> Option<Vec<Vec<String>>> {
     let mut matches: Vec<Vec<String>> = Vec::new();
-    let mut i = 0;
-    let max = rawText.len();
+    let mut i = 0_isize;
+    let max = rawText.len() as isize;
 
     // let equals_regex = Regex::new(EQUALS).unwrap();
     // let unescaped_semis = fancy_regex::Regex::new(UNESCAPED_SEMICOLONS).unwrap();
@@ -195,14 +195,14 @@ pub fn matchVCardPrefixedField(
         if i > 0 {
             i -= 1; // Find from i-1 not i since looking at the preceding character
         }
-        let cap_text = &rawText[i..];
+        let cap_text = &rawText[i as usize..];
         let cap_maybe = matcher_primary.captures(cap_text);
         //let matcher_maybe = matcher_primary.find_at(&lower_case_raw_text, i);
         if cap_maybe.is_none() {
             break;
         }
         let matcher = cap_maybe?;
-        i += matcher.get(0)?.end(); // group 0 = whole pattern; end(0) is past final colon
+        i += matcher.get(0)?.end() as isize; // group 0 = whole pattern; end(0) is past final colon
 
         let metadataString = matcher.get(1); // group 1 = metadata substring
         let mut metadata: Vec<String> = Vec::new();
@@ -236,18 +236,18 @@ pub fn matchVCardPrefixedField(
         }
 
         let matchStart = i; // Found the start of a match here
-        while let Some(pos) = rawText[i..].find('\n') {
+        while let Some(pos) = rawText[i as usize..].find('\n') {
             // Really, end in \r\n
-            i += pos; // + i;
+            i += pos as isize; // + i;
                       // while (i = rawText.indexOf('\n', i)) >= 0 { // Really, end in \r\n
-            if i < rawText.len() - 1 &&           // But if followed by tab or space,
-            (rawText.chars().nth(i + 1)? == ' ' ||        // this is only a continuation
-             rawText.chars().nth(i + 1)? == '\t')
+            if i < rawText.len() as isize- 1 &&           // But if followed by tab or space,
+            (rawText.chars().nth(i as usize+ 1)? == ' ' ||        // this is only a continuation
+             rawText.chars().nth(i as usize+ 1)? == '\t')
             {
                 i += 2; // Skip \n and continutation whitespace
             } else if quotedPrintable &&             // If preceded by = in quoted printable
-                   ((i >= 1 && rawText.chars().nth(i - 1)? == '=') || // this is a continuation
-                    (i >= 2 && rawText.chars().nth(i - 2)? == '='))
+                   ((i >= 1 && rawText.chars().nth(i as usize- 1)? == '=') || // this is a continuation
+                    (i >= 2 && rawText.chars().nth(i as usize - 2)? == '='))
             {
                 i += 1; // Skip \n
             } else {
@@ -263,10 +263,10 @@ pub fn matchVCardPrefixedField(
             // if matches == null {
             //   matches = new ArrayList<>(1); // lazy init
             // }
-            if i >= 1 && rawText.chars().nth(i - 1)? == '\r' {
+            if i >= 1 && rawText.chars().nth(i as usize- 1)? == '\r' {
                 i -= 1; // Back up over \r, which really should be there
             }
-            let mut element = rawText[matchStart..i].to_owned();
+            let mut element = rawText[matchStart as usize..i as usize].to_owned();
             if trim {
                 element = element.trim().to_owned();
             }
diff --git a/src/common/mod.rs b/src/common/mod.rs
index 7a77628..aa2e9b0 100644
--- a/src/common/mod.rs
+++ b/src/common/mod.rs
@@ -2342,7 +2342,7 @@ impl GridSampler for DefaultGridSampler {
         dimensionY: u32,
         transform: &PerspectiveTransform,
     ) -> Result<BitMatrix, Exceptions> {
-        if dimensionX <= 0 || dimensionY <= 0 {
+        if dimensionX == 0 || dimensionY == 0 {
             return Err(Exceptions::NotFoundException(
                 "getNotFoundInstance".to_owned(),
             ));
@@ -3227,7 +3227,7 @@ impl ECIInput for MinimalECIInput {
         if index >= self.length() as u32 {
             return Err(Exceptions::IndexOutOfBoundsException(index.to_string()));
         }
-        Ok(self.bytes[index as usize] > 255 && self.bytes[index as usize] <= u16::MAX)
+        Ok(self.bytes[index as usize] > 255)// && self.bytes[index as usize] <= u16::MAX)
     }
 
     /**
diff --git a/src/common/reedsolomon/mod.rs b/src/common/reedsolomon/mod.rs
index 7b0d0b2..3dccd6d 100644
--- a/src/common/reedsolomon/mod.rs
+++ b/src/common/reedsolomon/mod.rs
@@ -967,7 +967,7 @@ impl ReedSolomonEncoder {
             ));
         }
         let data_bytes = to_encode.len() - ec_bytes;
-        if data_bytes <= 0 {
+        if data_bytes == 0 {
             return Err(Exceptions::IllegalArgumentException(
                 "No data bytes provided".to_owned(),
             ));