cyclane/wacc_37
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

feat: improved error messages

Browse Source
This commit is contained in:
Guy C 2025-02-04 17:03:46 +00:00
parent 4e50ed35ba
commit 4602b75628
1 changed files with 23 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
src/main/wacc/parser.scala
View File

@ -6,7 +6,8 @@ import parsley.Parsley.{atomic, many, notFollowedBy, pure}
import parsley.combinator.{countSome, sepBy}
import parsley.expr.{precedence, SOps, InfixL, InfixN, InfixR, Prefix, Atoms}
import parsley.errors.combinator._
import parsley.cats.combinator.{sepBy1, some}
import parsley.syntax.zipped._
import parsley.cats.combinator.{some}
import cats.data.NonEmptyList
object parser {
@ -72,12 +73,12 @@ object parser {
)
private lazy val `<pair-elem-type>` =
(`<base-type>` <**> (`<array-type>` </> identity)) |
`<pair-type>` ~> ((`<pair-elems-type>` <**> `<array-type>`) </> UntypedPairType)
`<pair-type>` ~> ((`<pair-elems-type>` <**> `<array-type>`.explain("for a pair to contain a pair type, it must be an array or erased pair")) </> UntypedPairType)
// TODO: better explanation here?
// Statements
private lazy val `<program>` = Program(
"begin" ~> many(atomic(`<type>` <~> `<ident>` <~ "(") <**> `<partial-func-decl>`),
`<stmt>` <~ "end"
"begin" ~> many(atomic(`<type>`.label("function declaration") <~> `<ident>` <~ "(") <**> `<partial-func-decl>`).label("function declaration"),
`<stmt>`.label("main program body") <~ "end"
)
private lazy val `<partial-func-decl>` =
(sepBy(`<param>`, ",") <~ ")" <~ "is" <~> `<stmt>`.guardAgainst {
@ -87,23 +88,28 @@ object parser {
}
private lazy val `<param>` = Param(`<type>`, `<ident>`)
private lazy val `<stmt>`: Parsley[NonEmptyList[Stmt]] =
sepBy1(`<basic-stmt>`, ";")
(
`<basic-stmt>`.label("main program body"),
(many(";" ~> `<basic-stmt>`.label("statement after ';'"))) </> Nil
).zipped(NonEmptyList.apply)
private lazy val `<basic-stmt>` =
(Skip from "skip")
| Read("read" ~> `<lvalue>`)
| Free("free" ~> `<expr>`)
| Return("return" ~> `<expr>`)
| Exit("exit" ~> `<expr>`)
| Print("print" ~> `<expr>`, pure(false))
| Print("println" ~> `<expr>`, pure(true))
| Free("free" ~> `<expr>`.label("a valid expression"))
| Return("return" ~> `<expr>`.label("a valid expression"))
| Exit("exit" ~> `<expr>`.label("a valid expression"))
| Print("print" ~> `<expr>`.label("a valid expression"), pure(false))
| Print("println" ~> `<expr>`.label("a valid expression"), pure(true))
| If(
"if" ~> `<expr>` <~ "then",
"if" ~> `<expr>`.label("a valid expression") <~ "then",
`<stmt>` <~ "else",
`<stmt>` <~ "fi"
)
| While("while" ~> `<expr>` <~ "do", `<stmt>` <~ "done")
| While("while" ~> `<expr>`.label("a valid expression") <~ "do", `<stmt>` <~ "done")
| Block("begin" ~> `<stmt>` <~ "end")
| VarDecl(`<type>`, `<ident>` <~ "=", `<rvalue>`)
| VarDecl(`<type>`, `<ident>` <~ "=", `<rvalue>`.label("a valid initial value for variable"))
// TODO: Can we inline the name of the variable in the message
| Assign(`<lvalue>` <~ "=", `<rvalue>`)
private lazy val `<lvalue>`: Parsley[LValue] =
`<pair-elem>` | `<ident-or-array-elem>`
@ -117,9 +123,10 @@ object parser {
Call(
"call" ~> `<ident>` <~ "(",
sepBy(`<expr>`, ",") <~ ")"
) | `<expr>`
) | `<expr>`.label("valid expression")
private lazy val `<pair-elem>` =
Fst("fst" ~> `<lvalue>`) | Snd("snd" ~> `<lvalue>`)
Fst("fst" ~> `<lvalue>`.label("a valid pair"))
| Snd("snd" ~> `<lvalue>`.label("a valid pair"))
private lazy val `<array-liter>` = ArrayLiter(
"[" ~> sepBy(`<expr>`, ",") <~ "]"
)