Support type arguments on methods (FuelLabs#2974)

Fixes FuelLabs#2948. Now it's possible to write `foo.bar::<Baz>()`. The parser will also do recovery for `foo.field::<Args>`. Co-authored-by: Emily Herbert <[email protected]> Co-authored-by: Mohammad Fawaz <[email protected]>
mosker · Oct 10, 2022 · b6b1432 · b6b1432
1 parent dab1c74
commit b6b1432
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Showing 20 changed files with 144 additions and 39 deletions.
diff --git a/sway-ast/src/expr/mod.rs b/sway-ast/src/expr/mod.rs
@@ -1,4 +1,4 @@
-use crate::priv_prelude::*;
+use crate::{priv_prelude::*, PathExprSegment};
 
 pub mod asm;
 pub mod op_code;
@@ -50,7 +50,7 @@ pub enum Expr {
     MethodCall {
         target: Box<Expr>,
         dot_token: DotToken,
-        name: Ident,
+        path_seg: PathExprSegment,
         contract_args_opt: Option<Braces<Punctuated<ExprStructField, CommaToken>>>,
         args: Parens<Punctuated<Expr, CommaToken>>,
     },

diff --git a/sway-ast/src/path.rs b/sway-ast/src/path.rs
@@ -24,7 +24,7 @@ impl Spanned for PathExpr {
             None => self.prefix.span(),
         };
         let end = match self.suffix.last() {
-            Some((_double_colon_token, path_expr_segment)) => path_expr_segment.span(),
+            Some((_, path_expr_segment)) => path_expr_segment.span(),
             None => self.prefix.span(),
         };
         Span::join(start, end)
@@ -51,7 +51,7 @@ impl Spanned for PathExprSegment {
             None => self.name.span(),
         };
         let end = match &self.generics_opt {
-            Some((_double_colon_token, generic_args)) => generic_args.span(),
+            Some((_, generic_args)) => generic_args.span(),
             None => self.name.span(),
         };
         Span::join(start, end)
@@ -75,7 +75,7 @@ impl Spanned for PathType {
             None => self.prefix.span(),
         };
         let end = match self.suffix.last() {
-            Some((_double_colon_token, path_type_segment)) => path_type_segment.span(),
+            Some((_, path_type_segment)) => path_type_segment.span(),
             None => self.prefix.span(),
         };
         Span::join(start, end)
@@ -96,7 +96,7 @@ impl Spanned for PathTypeSegment {
             None => self.name.span(),
         };
         let end = match &self.generics_opt {
-            Some((_double_colon_token, generic_args)) => generic_args.span(),
+            Some((_, generic_args)) => generic_args.span(),
             None => self.name.span(),
         };
         Span::join(start, end)

diff --git a/sway-core/src/convert_parse_tree.rs b/sway-core/src/convert_parse_tree.rs
@@ -1265,16 +1265,21 @@ fn struct_path_and_fields_to_struct_expression(
 fn method_call_fields_to_method_application_expression(
     ec: &mut ErrorContext,
     target: Box<Expr>,
-    name: Ident,
+    path_seg: PathExprSegment,
     contract_args_opt: Option<Braces<Punctuated<ExprStructField, CommaToken>>>,
     args: Parens<Punctuated<Expr, CommaToken>>,
 ) -> Result<Box<MethodApplicationExpression>, ErrorEmitted> {
+    let (method_name, type_arguments) = path_expr_segment_to_ident_or_type_argument(ec, path_seg)?;
+
+    let span = match &*type_arguments {
+        [] => method_name.span(),
+        [.., last] => Span::join(method_name.span(), last.span.clone()),
+    };
+
     let method_name_binding = TypeBinding {
-        inner: MethodName::FromModule {
-            method_name: name.clone(),
-        },
-        type_arguments: vec![],
-        span: name.span(),
+        inner: MethodName::FromModule { method_name },
+        type_arguments,
+        span,
     };
     let contract_call_params = match contract_args_opt {
         None => Vec::new(),
@@ -1690,7 +1695,7 @@ fn expr_to_expression(ec: &mut ErrorContext, expr: Expr) -> Result<Expression, E
         },
         Expr::MethodCall {
             target,
-            name,
+            path_seg,
             args,
             contract_args_opt,
             ..
@@ -1699,7 +1704,7 @@ fn expr_to_expression(ec: &mut ErrorContext, expr: Expr) -> Result<Expression, E
                 method_call_fields_to_method_application_expression(
                     ec,
                     target,
-                    name,
+                    path_seg,
                     contract_args_opt,
                     args,
                 )?;
@@ -2272,9 +2277,8 @@ fn path_expr_segment_to_ident_or_type_argument(
         };
         return Err(ec.error(error));
     }
-    let generic_args = generics_opt.map(|(_, y)| y);
-    let type_args = match generic_args {
-        Some(x) => generic_args_to_type_arguments(ec, x)?,
+    let type_args = match generics_opt {
+        Some((_, x)) => generic_args_to_type_arguments(ec, x)?,
         None => Default::default(),
     };
     Ok((name, type_args))

diff --git a/sway-parse/src/error.rs b/sway-parse/src/error.rs
@@ -76,6 +76,8 @@ pub enum ParseErrorKind {
     ExpectedDocComment,
     #[error("Use the `struct` keyword to define records, instead of `class`.")]
     UnexpectedClass,
+    #[error("Field projections, e.g., `foo.bar` cannot have type arguments.")]
+    FieldProjectionWithGenericArgs,
 }
 
 #[derive(Debug, Error, Clone, PartialEq, Eq, Hash)]

diff --git a/sway-parse/src/expr/mod.rs b/sway-parse/src/expr/mod.rs
@@ -16,10 +16,10 @@ use sway_ast::punctuated::Punctuated;
 use sway_ast::token::Delimiter;
 use sway_ast::{
     AbiCastArgs, CodeBlockContents, Expr, ExprArrayDescriptor, ExprStructField,
-    ExprTupleDescriptor, IfCondition, IfExpr, LitInt, Literal, MatchBranch, MatchBranchKind,
-    Statement, StatementLet,
+    ExprTupleDescriptor, GenericArgs, IfCondition, IfExpr, LitInt, Literal, MatchBranch,
+    MatchBranchKind, PathExprSegment, Statement, StatementLet,
 };
-use sway_types::{Ident, Spanned};
+use sway_types::{Ident, Span, Spanned};
 
 mod asm;
 pub mod op_code;
@@ -495,36 +495,36 @@ fn parse_projection(parser: &mut Parser, ctx: ParseExprCtx) -> ParseResult<Expr>
             let target = Box::new(expr);
 
             // Try parsing a field access or a method call.
-            if let Some(name) = parser.take() {
+            if let Some(path_seg) = parser.guarded_parse::<Ident, PathExprSegment>()? {
                 if !ctx.parsing_conditional {
                     if let Some(contract_args) = Braces::try_parse(parser)? {
-                        let contract_args_opt = Some(contract_args);
-                        let args = Parens::parse(parser)?;
                         expr = Expr::MethodCall {
                             target,
                             dot_token,
-                            name,
-                            contract_args_opt,
-                            args,
+                            path_seg,
+                            contract_args_opt: Some(contract_args),
+                            args: Parens::parse(parser)?,
                         };
                         continue;
                     }
                 }
                 if let Some(args) = Parens::try_parse(parser)? {
-                    let contract_args_opt = None;
                     expr = Expr::MethodCall {
                         target,
                         dot_token,
-                        name,
-                        contract_args_opt,
+                        path_seg,
+                        contract_args_opt: None,
                         args,
                     };
                     continue;
                 }
+
+                // No arguments, so this is a field projection.
+                ensure_field_projection_no_generics(parser, &path_seg.generics_opt);
                 expr = Expr::FieldProjection {
                     target,
                     dot_token,
-                    name,
+                    name: path_seg.name,
                 };
                 continue;
             }
@@ -569,6 +569,17 @@ fn parse_projection(parser: &mut Parser, ctx: ParseExprCtx) -> ParseResult<Expr>
     }
 }
 
+/// Ensure we don't have `foo.bar::<...>` where `bar` isn't a method call.
+fn ensure_field_projection_no_generics(
+    parser: &mut Parser,
+    generic_args: &Option<(DoubleColonToken, GenericArgs)>,
+) {
+    if let Some((dct, generic_args)) = generic_args {
+        let span = Span::join(dct.span(), generic_args.span());
+        parser.emit_error_with_span(ParseErrorKind::FieldProjectionWithGenericArgs, span);
+    }
+}
+
 fn parse_func_app(parser: &mut Parser, ctx: ParseExprCtx) -> ParseResult<Expr> {
     let mut expr = parse_atom(parser, ctx)?;
     if expr.is_control_flow() && ctx.at_start_of_statement {

diff --git a/swayfmt/src/utils/language/expr/mod.rs b/swayfmt/src/utils/language/expr/mod.rs
@@ -14,9 +14,9 @@ use sway_ast::{
     keywords::{CommaToken, DotToken},
     punctuated::Punctuated,
     token::Delimiter,
-    Braces, CodeBlockContents, Expr, ExprStructField, MatchBranch, PathExpr,
+    Braces, CodeBlockContents, Expr, ExprStructField, MatchBranch, PathExpr, PathExprSegment,
 };
-use sway_types::{Ident, Spanned};
+use sway_types::Spanned;
 
 pub(crate) mod abi_cast;
 pub(crate) mod asm_block;
@@ -210,7 +210,7 @@ impl Format for Expr {
             Self::MethodCall {
                 target,
                 dot_token,
-                name,
+                path_seg,
                 contract_args_opt,
                 args,
             } => {
@@ -227,7 +227,7 @@ impl Format for Expr {
                         format_method_call(
                             target,
                             dot_token,
-                            name,
+                            path_seg,
                             contract_args_opt,
                             args,
                             &mut buf,
@@ -254,7 +254,7 @@ impl Format for Expr {
                         format_method_call(
                             target,
                             dot_token,
-                            name,
+                            path_seg,
                             contract_args_opt,
                             args,
                             formatted_code,
@@ -622,7 +622,7 @@ fn format_expr_struct(
 fn format_method_call(
     target: &Expr,
     dot_token: &DotToken,
-    name: &Ident,
+    path_seg: &PathExprSegment,
     contract_args_opt: &Option<Braces<Punctuated<ExprStructField, CommaToken>>>,
     args: &Parens<Punctuated<Expr, CommaToken>>,
     formatted_code: &mut FormattedCode,
@@ -638,7 +638,7 @@ fn format_method_call(
     }
     target.format(formatted_code, formatter)?;
     write!(formatted_code, "{}", dot_token.span().as_str())?;
-    name.format(formatted_code, formatter)?;
+    path_seg.format(formatted_code, formatter)?;
     if let Some(contract_args) = &contract_args_opt {
         ExprStructField::open_curly_brace(formatted_code, formatter)?;
         let contract_args = &contract_args.get();
@@ -787,14 +787,14 @@ fn expr_leaf_spans(expr: &Expr) -> Vec<ByteSpan> {
         Expr::MethodCall {
             target,
             dot_token,
-            name,
+            path_seg,
             contract_args_opt,
             args,
         } => {
             let mut collected_spans = Vec::new();
             collected_spans.append(&mut target.leaf_spans());
             collected_spans.push(ByteSpan::from(dot_token.span()));
-            collected_spans.push(ByteSpan::from(name.span()));
+            collected_spans.push(ByteSpan::from(path_seg.span()));
             if let Some(contract_args) = contract_args_opt {
                 collected_spans.append(&mut contract_args.leaf_spans());
             }

diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/Forc.lock b/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/Forc.lock
@@ -0,0 +1,4 @@
+[[package]]
+name = 'method_type_args_sound'
+source = 'root'
+dependencies = []
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/Forc.toml b/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/Forc.toml
@@ -0,0 +1,6 @@
+[project]
+authors = ["Fuel Labs <[email protected]>"]
+license = "Apache-2.0"
+name = "method_type_args_sound"
+entry = "main.sw"
+implicit-std = false
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/json_abi_oracle.json b/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/json_abi_oracle.json
@@ -0,0 +1 @@
+[]
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/src/main.sw b/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/src/main.sw
@@ -0,0 +1,11 @@
+contract;
+
+struct A {}
+
+impl A {
+    fn generic<T>(self, x: T) -> T { x }
+}
+
+fn foo() -> bool {
+    A {}.generic::<u8>(true)
+}
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/test.toml b/test/src/e2e_vm_tests/test_programs/should_fail/method_type_args_sound/test.toml
@@ -0,0 +1,4 @@
+category = "fail"
+
+# check: $()This parameter was declared as type u8, but argument of type bool was provided.
+# check: $()Mismatched types.
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/Forc.lock b/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/Forc.lock
@@ -0,0 +1,4 @@
+[[package]]
+name = 'unexpected_field_type_args'
+source = 'root'
+dependencies = []
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/Forc.toml b/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/Forc.toml
@@ -0,0 +1,6 @@
+[project]
+authors = ["Fuel Labs <[email protected]>"]
+license = "Apache-2.0"
+name = "unexpected_field_type_args"
+entry = "main.sw"
+implicit-std = false
diff --git a/...rc/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/json_abi_oracle.json b/...rc/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/json_abi_oracle.json
@@ -0,0 +1 @@
+[]
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/src/main.sw b/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/src/main.sw
@@ -0,0 +1,7 @@
+contract;
+
+struct A {
+    field: bool,
+}
+
+fn foo(a: A) -> bool { a.field::<bool> && 0 } // recovery witness.
diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/test.toml b/test/src/e2e_vm_tests/test_programs/should_fail/unexpected_field_type_args/test.toml
@@ -0,0 +1,4 @@
+category = "fail"
+
+# check: $()Field projections, e.g., `foo.bar` cannot have type arguments.
+# check: $()Mismatched types.
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/Forc.lock b/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/Forc.lock
@@ -0,0 +1,14 @@
+[[package]]
+name = 'core'
+source = 'path+from-root-1C4B691D300E54B2'
+dependencies = []
+
+[[package]]
+name = 'method_type_args'
+source = 'root'
+dependencies = ['std']
+
+[[package]]
+name = 'std'
+source = 'path+from-root-1C4B691D300E54B2'
+dependencies = ['core']
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/Forc.toml b/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/Forc.toml
@@ -0,0 +1,8 @@
+[project]
+authors = ["Fuel Labs <[email protected]>"]
+license = "Apache-2.0"
+name = "method_type_args"
+entry = "main.sw"
+
+[dependencies]
+std = { path = "../../../../../../../sway-lib-std" }
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/src/main.sw b/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/src/main.sw
@@ -0,0 +1,15 @@
+script;
+
+struct A {}
+
+impl A {
+    fn generic<T>(self, x: T) -> T { x }
+}
+
+fn foo() -> bool {
+    A {}.generic::<bool>(true)
+}
+
+fn main() {
+    let _ = foo();
+}
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/test.toml b/test/src/e2e_vm_tests/test_programs/should_pass/language/method_type_args/test.toml
@@ -0,0 +1,3 @@
+category = "run"
+expected_result = { action = "return", value = 0 }
+validate_abi = false