Merge #1117

1117: [WIP] Tuple struct index inference r=matklad a=robojumper

The first commit adds a helper struct `ast::FieldKind` to facilitate inference.

The second commit adds a slightly modified test from #1109 while mentioning that there is a problem with how we're handling tuple indexing / floats.

cc #1109 

Co-authored-by: robojumper <[email protected]>

9 files changed, 126 insertions, 12 deletions

diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 9f5c41b0c..a06a6375d 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -17,7 +17,7 @@ pub use self::{
     generated::*,
     traits::*,
     tokens::*,
-    extensions::{PathSegmentKind, StructKind, SelfParamKind},
+    extensions::{PathSegmentKind, StructKind, FieldKind, SelfParamKind},
     expr_extensions::{ElseBranch, PrefixOp, BinOp, LiteralKind},
 };
 
diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index aec57c380..ca33b43e7 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -3,11 +3,8 @@
 
 use itertools::Itertools;
 
-use crate::{
-    SmolStr, SyntaxToken,
-    ast::{self, AstNode, children, child_opt},
-    SyntaxKind::*,
-};
+use crate::{SmolStr, SyntaxToken, ast::{self, AstNode, children, child_opt}, SyntaxKind::*, SyntaxElement};
+use ra_parser::SyntaxKind;
 
 impl ast::Name {
     pub fn text(&self) -> &SmolStr {
@@ -217,6 +214,33 @@ impl ast::ExprStmt {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum FieldKind<'a> {
+    Name(&'a ast::NameRef),
+    Index(SyntaxToken<'a>),
+}
+
+impl ast::FieldExpr {
+    pub fn index_token(&self) -> Option<SyntaxToken> {
+        self.syntax
+            .children_with_tokens()
+            // FIXME: Accepting floats here to reject them in validation later
+            .find(|c| c.kind() == SyntaxKind::INT_NUMBER || c.kind() == SyntaxKind::FLOAT_NUMBER)
+            .as_ref()
+            .and_then(SyntaxElement::as_token)
+    }
+
+    pub fn field_access(&self) -> Option<FieldKind> {
+        if let Some(nr) = self.name_ref() {
+            Some(FieldKind::Name(nr))
+        } else if let Some(tok) = self.index_token() {
+            Some(FieldKind::Index(tok))
+        } else {
+            None
+        }
+    }
+}
+
 impl ast::RefPat {
     pub fn is_mut(&self) -> bool {
         self.syntax().children_with_tokens().any(|n| n.kind() == MUT_KW)
diff --git a/crates/ra_syntax/src/syntax_error.rs b/crates/ra_syntax/src/syntax_error.rs
index 4b8c22a57..4198eefdb 100644
--- a/crates/ra_syntax/src/syntax_error.rs
+++ b/crates/ra_syntax/src/syntax_error.rs
@@ -95,6 +95,7 @@ pub enum SyntaxErrorKind {
     InvalidSuffix,
     InvalidBlockAttr,
     InvalidMatchInnerAttr,
+    InvalidTupleIndexFormat,
 }
 
 impl fmt::Display for SyntaxErrorKind {
@@ -139,6 +140,9 @@ impl fmt::Display for SyntaxErrorKind {
             InvalidMatchInnerAttr => {
                 write!(f, "Inner attributes are only allowed directly after the opening brace of the match expression")
             }
+            InvalidTupleIndexFormat => {
+                write!(f, "Tuple (struct) field access is only allowed through decimal integers with no underscores or suffix")
+            }
             ParseError(msg) => write!(f, "{}", msg.0),
         }
     }
diff --git a/crates/ra_syntax/src/validation.rs b/crates/ra_syntax/src/validation.rs
index fc534df83..c2f545173 100644
--- a/crates/ra_syntax/src/validation.rs
+++ b/crates/ra_syntax/src/validation.rs
@@ -3,6 +3,7 @@ mod byte_string;
 mod char;
 mod string;
 mod block;
+mod field_expr;
 
 use crate::{
     SourceFile, SyntaxError, AstNode, SyntaxNode,
@@ -17,6 +18,7 @@ pub(crate) fn validate(file: &SourceFile) -> Vec<SyntaxError> {
         let _ = visitor_ctx(&mut errors)
             .visit::<ast::Literal, _>(validate_literal)
             .visit::<ast::Block, _>(block::validate_block_node)
+            .visit::<ast::FieldExpr, _>(field_expr::validate_field_expr_node)
             .accept(node);
     }
     errors
diff --git a/crates/ra_syntax/src/validation/field_expr.rs b/crates/ra_syntax/src/validation/field_expr.rs
new file mode 100644
index 000000000..2b405062e
--- /dev/null
+++ b/crates/ra_syntax/src/validation/field_expr.rs
@@ -0,0 +1,12 @@
+use crate::{ast::{self, FieldKind},

+            SyntaxError,

+            SyntaxErrorKind::*,

+};

+

+pub(crate) fn validate_field_expr_node(node: &ast::FieldExpr, errors: &mut Vec<SyntaxError>) {

+    if let Some(FieldKind::Index(idx)) = node.field_access() {

+        if idx.text().chars().any(|c| c < '0' || c > '9') {

+            errors.push(SyntaxError::new(InvalidTupleIndexFormat, idx.range()));

+        }

+    }

+}

diff --git a/crates/ra_syntax/tests/data/parser/inline/err/0010_bad_tuple_index_expr.rs b/crates/ra_syntax/tests/data/parser/inline/err/0010_bad_tuple_index_expr.rs
new file mode 100644
index 000000000..30cc49138
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/err/0010_bad_tuple_index_expr.rs
@@ -0,0 +1,5 @@
+fn foo() {
+    x.0.;
+    x.1i32;
+    x.0x01;
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/err/0010_bad_tuple_index_expr.txt b/crates/ra_syntax/tests/data/parser/inline/err/0010_bad_tuple_index_expr.txt
new file mode 100644
index 000000000..c111f60ea
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/err/0010_bad_tuple_index_expr.txt
@@ -0,0 +1,51 @@
+SOURCE_FILE@[0; 47)
+  FN_DEF@[0; 46)
+    FN_KW@[0; 2) "fn"
+    WHITESPACE@[2; 3) " "
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7) "("
+      R_PAREN@[7; 8) ")"
+    WHITESPACE@[8; 9) " "
+    BLOCK@[9; 46)
+      L_CURLY@[9; 10) "{"
+      WHITESPACE@[10; 15) "\n    "
+      EXPR_STMT@[15; 20)
+        FIELD_EXPR@[15; 19)
+          PATH_EXPR@[15; 16)
+            PATH@[15; 16)
+              PATH_SEGMENT@[15; 16)
+                NAME_REF@[15; 16)
+                  IDENT@[15; 16) "x"
+          DOT@[16; 17) "."
+          err: `Tuple (struct) field access is only allowed through decimal integers with no underscores or suffix`
+          FLOAT_NUMBER@[17; 19) "0."
+        SEMI@[19; 20) ";"
+      WHITESPACE@[20; 25) "\n    "
+      EXPR_STMT@[25; 32)
+        FIELD_EXPR@[25; 31)
+          PATH_EXPR@[25; 26)
+            PATH@[25; 26)
+              PATH_SEGMENT@[25; 26)
+                NAME_REF@[25; 26)
+                  IDENT@[25; 26) "x"
+          DOT@[26; 27) "."
+          err: `Tuple (struct) field access is only allowed through decimal integers with no underscores or suffix`
+          INT_NUMBER@[27; 31) "1i32"
+        SEMI@[31; 32) ";"
+      WHITESPACE@[32; 37) "\n    "
+      EXPR_STMT@[37; 44)
+        FIELD_EXPR@[37; 43)
+          PATH_EXPR@[37; 38)
+            PATH@[37; 38)
+              PATH_SEGMENT@[37; 38)
+                NAME_REF@[37; 38)
+                  IDENT@[37; 38) "x"
+          DOT@[38; 39) "."
+          err: `Tuple (struct) field access is only allowed through decimal integers with no underscores or suffix`
+          INT_NUMBER@[39; 43) "0x01"
+        SEMI@[43; 44) ";"
+      WHITESPACE@[44; 45) "\n"
+      R_CURLY@[45; 46) "}"
+  WHITESPACE@[46; 47) "\n"
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.rs b/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.rs
index 3e69538e5..b8da2ddc3 100644
--- a/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.rs
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.rs
@@ -1,4 +1,5 @@
 fn foo() {
     x.foo;
     x.0.bar;
+    x.0();
 }
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.txt b/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.txt
index a86702843..78054ec5a 100644
--- a/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.txt
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0011_field_expr.txt
@@ -1,5 +1,5 @@
-SOURCE_FILE@[0; 37)
-  FN_DEF@[0; 36)
+SOURCE_FILE@[0; 48)
+  FN_DEF@[0; 47)
     FN_KW@[0; 2) "fn"
     WHITESPACE@[2; 3) " "
     NAME@[3; 6)
@@ -8,7 +8,7 @@ SOURCE_FILE@[0; 37)
       L_PAREN@[6; 7) "("
       R_PAREN@[7; 8) ")"
     WHITESPACE@[8; 9) " "
-    BLOCK@[9; 36)
+    BLOCK@[9; 47)
       L_CURLY@[9; 10) "{"
       WHITESPACE@[10; 15) "\n    "
       EXPR_STMT@[15; 21)
@@ -37,6 +37,21 @@ SOURCE_FILE@[0; 37)
           NAME_REF@[30; 33)
             IDENT@[30; 33) "bar"
         SEMI@[33; 34) ";"
-      WHITESPACE@[34; 35) "\n"
-      R_CURLY@[35; 36) "}"
-  WHITESPACE@[36; 37) "\n"
+      WHITESPACE@[34; 39) "\n    "
+      EXPR_STMT@[39; 45)
+        CALL_EXPR@[39; 44)
+          FIELD_EXPR@[39; 42)
+            PATH_EXPR@[39; 40)
+              PATH@[39; 40)
+                PATH_SEGMENT@[39; 40)
+                  NAME_REF@[39; 40)
+                    IDENT@[39; 40) "x"
+            DOT@[40; 41) "."
+            INT_NUMBER@[41; 42) "0"
+          ARG_LIST@[42; 44)
+            L_PAREN@[42; 43) "("
+            R_PAREN@[43; 44) ")"
+        SEMI@[44; 45) ";"
+      WHITESPACE@[45; 46) "\n"
+      R_CURLY@[46; 47) "}"
+  WHITESPACE@[47; 48) "\n"