1 files changed, 123 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/lexer/strings.rs b/crates/ra_syntax/src/lexer/strings.rs
new file mode 100644
index 000000000..5ff483d14
--- /dev/null
+++ b/crates/ra_syntax/src/lexer/strings.rs
@@ -0,0 +1,123 @@
+use SyntaxKind::{self, *};
+
+use lexer::ptr::Ptr;
+
+pub(crate) fn is_string_literal_start(c: char, c1: Option<char>, c2: Option<char>) -> bool {
+    match (c, c1, c2) {
+        ('r', Some('"'), _)
+        | ('r', Some('#'), _)
+        | ('b', Some('"'), _)
+        | ('b', Some('\''), _)
+        | ('b', Some('r'), Some('"'))
+        | ('b', Some('r'), Some('#')) => true,
+        _ => false,
+    }
+}
+
+pub(crate) fn scan_char(ptr: &mut Ptr) {
+    while let Some(c) = ptr.current() {
+        match c {
+            '\\' => {
+                ptr.bump();
+                if ptr.at('\\') || ptr.at('\'') {
+                    ptr.bump();
+                }
+            }
+            '\'' => {
+                ptr.bump();
+                return;
+            }
+            '\n' => return,
+            _ => {
+                ptr.bump();
+            }
+        }
+    }
+}
+
+pub(crate) fn scan_byte_char_or_string(ptr: &mut Ptr) -> SyntaxKind {
+    // unwrapping and not-exhaustive match are ok
+    // because of string_literal_start
+    let c = ptr.bump().unwrap();
+    match c {
+        '\'' => {
+            scan_byte(ptr);
+            BYTE
+        }
+        '"' => {
+            scan_byte_string(ptr);
+            BYTE_STRING
+        }
+        'r' => {
+            scan_raw_byte_string(ptr);
+            RAW_BYTE_STRING
+        }
+        _ => unreachable!(),
+    }
+}
+
+pub(crate) fn scan_string(ptr: &mut Ptr) {
+    while let Some(c) = ptr.current() {
+        match c {
+            '\\' => {
+                ptr.bump();
+                if ptr.at('\\') || ptr.at('"') {
+                    ptr.bump();
+                }
+            }
+            '"' => {
+                ptr.bump();
+                return;
+            }
+            _ => {
+                ptr.bump();
+            },
+        }
+    }
+}
+
+pub(crate) fn scan_raw_string(ptr: &mut Ptr) {
+    let mut hashes = 0;
+    while ptr.at('#') {
+        hashes += 1;
+        ptr.bump();
+    }
+    if !ptr.at('"') {
+        return;
+    }
+    ptr.bump();
+
+    while let Some(c) = ptr.bump() {
+        if c == '"' {
+            let mut hashes_left = hashes;
+            while ptr.at('#') && hashes_left > 0{
+                hashes_left -= 1;
+                ptr.bump();
+            }
+            if hashes_left == 0 {
+                return;
+            }
+        }
+    }
+}
+
+fn scan_byte(ptr: &mut Ptr) {
+    scan_char(ptr)
+}
+
+fn scan_byte_string(ptr: &mut Ptr) {
+    scan_string(ptr)
+}
+
+fn scan_raw_byte_string(ptr: &mut Ptr) {
+    if !ptr.at('"') {
+        return;
+    }
+    ptr.bump();
+
+    while let Some(c) = ptr.bump() {
+        if c == '"' {
+            return;
+        }
+    }
+}