Introduce minify_query

Useful to reduce the size of payload

Author: kamilkisiela

src/lib.rs

@@ -105,5 +105,6 @@ pub mod schema;
 
 pub use crate::query::parse_query;
 pub use crate::schema::parse_schema;
+pub use crate::query::minify_query;
 pub use crate::position::Pos;
 pub use crate::format::Style;

src/query/error.rs

@@ -13,7 +13,7 @@ pub type InternalError<'a> = Errors<Token<'a>, Token<'a>, Pos>;
 /// way to improve both error message and API.
 #[derive(Error, Debug)]
 #[error("query parse error: {}", _0)]
-pub struct ParseError(String);
+pub struct ParseError(pub (crate) String);
 
 impl<'a> From<InternalError<'a>> for ParseError {
     fn from(e: InternalError<'a>) -> ParseError {

src/query/minify.rs

@@ -0,0 +1,32 @@
+use crate::tokenizer::{Kind, Token, TokenStream};
+use super::ParseError;
+use combine::Positioned;
+use combine::StreamOnce;
+
+pub fn minify_query(source: String) ->  Result<String, ParseError> {
+  let mut bits: Vec<&str> = Vec::new();
+  let mut stream = TokenStream::new(source.as_str());
+  let mut prev_was_punctuator = false;
+
+  loop {
+      match stream.uncons() {
+          Ok(x) => {
+              let token: Token = x;
+              let is_non_punctuator = token.kind != Kind::Punctuator;
+
+              if prev_was_punctuator {
+                  if is_non_punctuator {
+                      bits.push(" ");
+                  }
+              }
+
+              bits.push(token.value);
+              prev_was_punctuator = is_non_punctuator;
+          }
+          Err(ref e) if e == &combine::easy::Error::end_of_input() => break,
+          Err(e) => return Err(ParseError(format!("{} at {}", e, stream.position()))),
+      }
+  }
+
+  Ok(bits.join(""))
+}

src/query/mod.rs

@@ -4,8 +4,9 @@ mod ast;
 mod error;
 mod format;
 mod grammar;
-
+mod minify;
 
 pub use self::grammar::{parse_query, consume_definition};
 pub use self::error::ParseError;
 pub use self::ast::*;
+pub use self::minify::minify_query;