Make tests pass by using multiple-k lookahead

schala-lang/language/src/parsing.rs

@@ -10,7 +10,7 @@
 //!
 //! ## Top level structure
 //!
-//! ```
+//! ```text
 //! program := (statement delimiter)* EOF
 //! delimiter := NEWLINE | ";"
 //! statement := expression | declaration
@@ -20,7 +20,7 @@
 //! ## Declarations
 //!
 //! ### Types
-//! ```
+//! ```text
 //! type_declaration := "type" type_declaration_body
 //! type_declaration_body := "alias" type_alias | "mut"? type_singleton_name "=" type_body
 //! type_alias := IDENTIFIER "=" type_name
@@ -31,7 +31,7 @@
 //! ```
 //! ### Functions
 //!
-//! ```
+//! ```text
 //! func_declaration := func_signature func_body
 //! func_body := ε | nonempty_func_body
 //! nonempty_func_body := "{" (statement delimiter)* "}"
@@ -42,11 +42,11 @@
 //! ```
 //!
 //! ### Variable bindings
-//! ```binding_declaration := "let" "mut"? IDENTIFIER "=" expresion```
+//! ```text binding_declaration := "let" "mut"? IDENTIFIER "=" expresion```
 //!
 //! ### Interfaces
 //!
-//! ```
+//! ```text
 //! interface_declaration := "interface" type_singleton_name signature_block
 //! impl_declaration := "impl" type_singleton_name decl_block | "impl" type_singleton_name "for" type_name decl_block
 //! decl_block := "{" (func_declaration)* "}"
@@ -55,7 +55,7 @@
 //!
 //! ### Type Annotations
 //!
-//! ```
+//! ```text
 //! type_anno := ":" type_name
 //! type_name := type_singleton_name | "(" type_names ")"
 //! type_names := ε | type_name (, type_name)*
@@ -64,7 +64,7 @@
 //! ```
 //!
 //! ## Expressions
-//! ```
+//! ```text
 //! expression := precedence_expr type_anno+
 //! precedence_expr := prefix_expr
 //! prefix_expr := prefix_op call_expr
@@ -79,7 +79,7 @@
 //!
 //! ### Primary expressions
 //!
-//! ```
+//! ```text
 //! list_expr := "[" (expression, ",")* "]"
 //! lambda_expr := "\\" lambda_param_list type_anno+ nonempty_func_body
 //! lambda_param_list := formal_param_list |  formal_param
@@ -89,7 +89,7 @@
 //! ```
 //!
 //! ## Literals
-//! ```
+//! ```text
 //! literal := "true" | "false" | number_literal | STR_LITERAL
 //! named_struct := IDENTIFIER record_block
 //! record_block :=  "{" (record_entry, ",")* | "}" //TODO support anonymus structs, update syntax
@@ -103,7 +103,7 @@
 //! ```
 //!
 //! ### Patterns
-//! ```
+//! ```text
 //! pattern := "(" (pattern, ",")* ")" | simple_pattern
 //! simple_pattern := pattern_literal | record_pattern | tuple_struct_pattern
 //! pattern_literal := "true" | "false" | signed_number_literal | STR_LITERAL | IDENTIFIER
@@ -114,7 +114,7 @@
 //! ```
 //!
 //! ### If-expressions
-//! ```
+//! ```text
 //! if_expr := "if" discriminator ("then" condititional | "is" simple_pattern_match | guard_block)
 //! discriminator := precedence_expr (operator)+
 //! conditional := expr_or_block else_clause
@@ -126,7 +126,7 @@
 //! ```
 //!
 //! ### While expressions
-//! ```
+//! ```text
 //! while_expr := "while" while_cond "{" (statement delimiter)* "}"
 //! while_cond := ε | expression | expression "is"  pattern //TODO maybe is-expresions should be primary
 //! ```
@@ -134,7 +134,7 @@
 //! //TODO this implies there must be at least one enumerator, which the parser doesn"t support right
 //! //this second, and maybe should fail later anyway
 //! ### For-expressions
-//! ```
+//! ```text
 //! for_expr := "for" (enumerator | "{" enumerators "}") for_expr_body
 //! for_expr_body := "return" expression |  "{" (statement delimiter)* "}"
 //! enumerators := enumerator ("," enumerators)*
@@ -642,9 +642,9 @@ impl Parser {
         InvocationArgument::Ignored
       },
       Identifier(s) => {
-        self.token_handler.next();
+        match self.token_handler.peek_kind_n(1) {
-        match self.token_handler.peek_kind() {
           Operator(ref op) if **op == "=" => {
+            self.token_handler.next();
             self.token_handler.next();
             let expr = self.expression()?;
             InvocationArgument::Keyword { name: s.clone(), expr }