Generate camelCase field names

2 files changed, 58 insertions, 2 deletions

diff --git a/nimpb/compiler/generator.nim b/nimpb/compiler/generator.nim
index fd820dd..5c4000a 100644
--- a/nimpb/compiler/generator.nim
+++ b/nimpb/compiler/generator.nim
@@ -8,6 +8,7 @@ import strutils
 import tables
 
 import nimpb/wkt/descriptor_pb
+import nimpb/utils
 
 import ../nimpb
 
@@ -303,7 +304,7 @@ proc sizeOfProc(field: Field): string =
 proc newField(file: ProtoFile, message: Message, desc: google_protobuf_FieldDescriptorProto): Field =
     new(result)
 
-    result.name = desc.name
+    result.name = toCamelCase(desc.name)
     result.number = desc.number
     result.label = desc.label
     result.ftype = desc.ftype
@@ -359,7 +360,7 @@ proc newField(file: ProtoFile, message: Message, desc: google_protobuf_FieldDesc
 proc newOneof(name: string): Oneof =
     new(result)
     result.fields = @[]
-    result.name = name
+    result.name = toCamelCase(name)
 
 proc newMessage(file: ProtoFile, names: Names, desc: google_protobuf_DescriptorProto): Message =
     new(result)
diff --git a/nimpb/utils.nim b/nimpb/utils.nim
new file mode 100644
index 0000000..8220ef2
--- /dev/null
+++ b/nimpb/utils.nim
@@ -0,0 +1,55 @@
+import strutils
+
+proc toCamelCase*(s: string): string =
+    ## Nimification of ToCamelCase() from
+    ## protobuf/src/google/protobuf/util/internal/utility.cc
+    result = newStringOfCap(len(s))
+
+    var
+        capitalizeNext = false
+        wasCapital = false
+        isCapital = false
+        firstWord = true
+
+    for index in 0..len(s)-1:
+        let ch = s[index]
+        wasCapital = isCapital
+        isCapital = isUpperAscii(ch)
+        if ch == '_':
+            capitalizeNext = true
+            if len(result) > 0:
+                firstWord = false
+        elif firstWord:
+            if len(result) > 0 and isCapital and (not wasCapital or (index+1 < len(s) and isLowerAscii(s[index+1]))):
+                firstWord = false
+                add(result, ch)
+            else:
+                add(result, toLowerAscii(ch))
+        elif capitalizeNext:
+            capitalizeNext = false
+            add(result, toUpperAscii(ch))
+        else:
+            add(result, toLowerAscii(ch))
+
+proc toSnakeCase*(s: string): string =
+    ## Nimification of ToSnakeCase() from
+    ## protobuf/src/google/protobuf/util/internal/utility.cc
+    result = newStringOfCap(len(s) * 2)
+
+    var
+        wasNotUnderscore = false
+        wasNotCap = false
+
+    for index in 0..len(s)-1:
+        if isUpperAscii(s[index]):
+            if wasNotUnderscore and
+               (wasNotCap or
+                (index+1 < len(s) and isLowerAscii(s[index+1]))):
+                add(result, '_')
+            add(result, toLowerAscii(s[index]))
+            wasNotUnderscore = true
+            wasNotCap = false
+        else:
+            add(result, s[index])
+            wasNotUnderscore = s[index] != '_'
+            wasNotCap = true