type name check fixes

compiler/fn.v

@@ -915,17 +915,6 @@ fn (p mut Parser) fn_call_args(f mut Fn) *Fn {
 	// p.gen(')')
 }
 
-fn contains_capital(s string) bool {
-	// for c in s {
-	for i := 0; i < s.len; i++ {
-		c := s[i]
-		if c >= `A` && c <= `Z` {
-			return true
-		}
-	}
-	return false
-}
-
 // "fn (int, string) int"
 fn (f Fn) typ_str() string {
 	mut sb := strings.new_builder(50)

compiler/parser.v

@@ -492,6 +492,9 @@ fn (p mut Parser) struct_decl() {
 		p.check(.dot)
 		name = p.check_name()
 	}
+	if !is_c && !good_type_name(name) {
+		p.error('bad struct name, e.g. use `HttpRequest` instead of `HTTPRequest`')  
+	} 
 	// Specify full type name
 	if !is_c && !p.builtin_pkg && p.mod != 'main' {
 		name = p.prepend_pkg(name)
@@ -592,7 +595,7 @@ fn (p mut Parser) struct_decl() {
 		if field_name in names {
 			p.error('duplicate field `$field_name`')
 		}
-		if p.mod != 'os' && contains_capital(field_name) {
+		if !is_c && p.mod != 'os' && contains_capital(field_name) {
 			p.error('struct fields cannot contain uppercase letters, use snake_case instead')
 		} 
 		names << field_name

compiler/scanner.v

@@ -758,3 +758,29 @@ fn (s mut Scanner) create_type_string(T Type, name string) {
 	s.inside_string = inside_string
 }
 
+fn contains_capital(s string) bool {
+	// for c in s {
+	for i := 0; i < s.len; i++ {
+		c := s[i]
+		if c >= `A` && c <= `Z` {
+			return true
+		}
+	}
+	return false
+}
+
+// HTTPRequest  bad
+// HttpRequest  good 
+fn good_type_name(s string) bool {
+	if s.len < 4 {
+		return true 
+	} 
+	for i in 2 .. s.len { 
+		if s[i].is_capital() && s[i-1].is_capital() && s[i-2].is_capital() {
+			return false 
+		} 
+	} 
+	return true 
+} 
+
+

vlib/builtin/int.v

@@ -188,6 +188,10 @@ pub fn (c byte) str() string {
 	return str
 }
 
+pub fn (c byte) is_capital() bool {
+	return c >= `A` && c <= `Z` 
+} 
+
 pub fn (b []byte) clone() []byte {
 	mut res := [byte(0); b.len] 
 	for i := 0; i < b.len; i++ {