new functions: better format (using template) and tostring

src/Terrabuild.Common/String.fs

@@ -29,3 +29,6 @@ let startsWith (start: string) (s: string) =
 
 let trim (s: string) =
     s.Trim()
+
+let replace (substring: string) (value: string) (s: string) =
+    s.Replace(substring, value)

src/Terrabuild.Configuration.Tests/TestFiles/WORKSPACE2

@@ -40,6 +40,7 @@ configuration {
         secret2: $list.2
         secret3: !false + !true
         secret4: format("1", 2, $toto, true, nothing)
+        secret5: tostring(42)
     }
 }
 

src/Terrabuild.Configuration.Tests/Workspace.fs

@@ -91,8 +91,9 @@ let parseWorkspace2() =
                                     Expr.Number 2
                                     Expr.Variable "toto"
                                     Expr.Bool true
-                                    Expr.Nothing
-                                ]) ] }
+                                    Expr.Nothing ])
+                                "secret5", Expr.Function (Function.ToString, [Expr.Number 42])
+                              ] }
 
         let extDotnet =
             { Container = Some "mcr.microsoft.com/dotnet/sdk:8.0.101"

src/Terrabuild.Configuration/Gen/ProjectParser.fsi

@@ -30,6 +30,7 @@ type token =
   | COUNT
   | VERSION
   | FORMAT
+  | TOSTRING
   | MINUS
   | PLUS
   | COMMA
@@ -84,6 +85,7 @@ type tokenId =
     | TOKEN_COUNT
     | TOKEN_VERSION
     | TOKEN_FORMAT
+    | TOKEN_TOSTRING
     | TOKEN_MINUS
     | TOKEN_PLUS
     | TOKEN_COMMA

src/Terrabuild.Configuration/Gen/WorkspaceParser.fsi

@@ -27,6 +27,7 @@ type token =
   | COUNT
   | VERSION
   | FORMAT
+  | TOSTRING
   | MINUS
   | PLUS
   | COMMA
@@ -78,6 +79,7 @@ type tokenId =
     | TOKEN_COUNT
     | TOKEN_VERSION
     | TOKEN_FORMAT
+    | TOKEN_TOSTRING
     | TOKEN_MINUS
     | TOKEN_PLUS
     | TOKEN_COMMA

src/Terrabuild.Configuration/ProjectParser/Lexer.fsl

@@ -30,6 +30,7 @@ rule token = parse
     | "count" { COUNT }
     | "version" { VERSION }
     | "format" { FORMAT }
+    | "tostring" { TOSTRING }
     | "??" { DOUBLE_QUESTION }
     | "?" { QUESTION }
     | ".?" { DOT_QUESTION }

src/Terrabuild.Configuration/ProjectParser/Parser.fsy

@@ -30,7 +30,7 @@ let debugPrint s = ignore s
 %token EQUAL DOUBLE_EQUAL NOT_EQUAL
 %token COMMA
 %token MINUS PLUS
-%token TRIM UPPER LOWER REPLACE COUNT VERSION FORMAT
+%token TRIM UPPER LOWER REPLACE COUNT VERSION FORMAT TOSTRING
 %token DOUBLE_QUESTION QUESTION COLON BANG
 %token EOF
 %token PROJECT EXTENSION TARGET 
@@ -149,6 +149,7 @@ Expr:
     | COUNT ExprTuple { Expr.Function (Function.Count, $2)}
     | VERSION ExprTuple { Expr.Function (Function.Version, $2) }
     | FORMAT ExprTuple { Expr.Function (Function.Format, $2) }
+    | TOSTRING ExprTuple { Expr.Function (Function.ToString, $2) }
     | Expr DOUBLE_QUESTION Expr { Expr.Function (Function.Coalesce, [$1; $3]) }
     | Expr QUESTION Expr COLON Expr { Expr.Function (Function.Ternary, [$1; $3; $5] ) }
     | BANG Expr { Expr.Function (Function.Not, [$2]) }

src/Terrabuild.Configuration/WorkspaceParser/Lexer.fsl

@@ -30,6 +30,7 @@ rule token = parse
     | "count" { COUNT }
     | "version" { VERSION }
     | "format" { FORMAT }
+    | "tostring" { TOSTRING }
     | "??" { DOUBLE_QUESTION }
     | "?" { QUESTION }
     | ".?" { DOT_QUESTION }

src/Terrabuild.Configuration/WorkspaceParser/Parser.fsy

@@ -30,7 +30,7 @@ let debugPrint s = ignore s
 %token EQUAL DOUBLE_EQUAL NOT_EQUAL
 %token COMMA
 %token MINUS PLUS
-%token TRIM UPPER LOWER REPLACE COUNT VERSION FORMAT
+%token TRIM UPPER LOWER REPLACE COUNT VERSION FORMAT TOSTRING
 %token DOUBLE_QUESTION QUESTION COLON BANG
 %token EOF
 %token WORKSPACE TARGET CONFIGURATION EXTENSION
@@ -134,6 +134,7 @@ Expr:
     | COUNT ExprTuple { Expr.Function (Function.Count, $2)}
     | VERSION ExprTuple { Expr.Function (Function.Version, $2) }
     | FORMAT ExprTuple { Expr.Function (Function.Format, $2) }
+    | TOSTRING ExprTuple { Expr.Function (Function.ToString, $2) }
     | Expr DOUBLE_QUESTION Expr { Expr.Function (Function.Coalesce, [$1; $3]) }
     | Expr QUESTION Expr COLON Expr { Expr.Function (Function.Ternary, [$1; $3; $5] ) }
     | BANG Expr { Expr.Function (Function.Not, [$2]) }

src/Terrabuild.Expressions.Tests/Eval.fs

@@ -166,15 +166,17 @@ let version() =
     result |> should equal expected
 
 [<Test>]
-let format() =
-    let expected = Value.String "\\o/42truetiti"
+let formatList() =
+    let expected = Value.String "\\o/THIS42ISAtrueTEMPLATEtiti"
     let expectedUsedVars = Set [ "toto" ]
 
     let context = { evaluationContext
                     with Variables = Map ["toto", Value.String "\\o/" |> mkVar] }
 
+    // format("{0}THIS{1}IS{2}A{3}TEMPLATE{4}", $toto, 42, nothing, true, "titi")
     let result, varUsed =
         eval context (Expr.Function (Function.Format, [
+            Expr.String "{0}THIS{1}IS{2}A{3}TEMPLATE{4}"
             Expr.Variable "toto"
             Expr.Number 42
             Expr.Nothing
@@ -183,6 +185,25 @@ let format() =
     varUsed |> should equal expectedUsedVars
     result |> should equal expected
 
+[<Test>]
+let formatMap() =
+    let expected = Value.String "THIS\\o/IS42ATEMPLATEtrue"
+    let expectedUsedVars = Set [ "args" ]
+
+    let context = { evaluationContext
+                    with Variables = Map ["args", Value.Map (Map [ "string", Value.String "\\o/"
+                                                                   "number", Value.Number 42
+                                                                   "nothing", Value.Nothing
+                                                                   "bool", Value.Bool true ]) |> mkVar ] }
+
+    // format("THIS{string}IS{number}A{nothing}TEMPLATE{bool}", $args)
+    let result, varUsed =
+        eval context (Expr.Function (Function.Format, [
+            Expr.String "THIS{string}IS{number}A{nothing}TEMPLATE{bool}"
+            Expr.Variable "args" ]))
+    varUsed |> should equal expectedUsedVars
+    result |> should equal expected
+
 
 [<Test>]
 let listItem() =

src/Terrabuild.Expressions/Eval.fs

@@ -11,6 +11,14 @@ type EvaluationContext = {
 }
 
 let rec eval (context: EvaluationContext) (expr: Expr) =
+    let valueToString v =
+        match v with
+        | Value.Nothing -> ""
+        | Value.Bool b -> if b then "true" else "false"
+        | Value.Number n -> $"{n}"
+        | Value.String s -> s
+        | _ -> TerrabuildException.Raise($"Unsupported type for format {v}")
+
     let rec eval (expr: Expr) =
         match expr with
         | Expr.Nothing -> Value.Nothing, Set.empty
@@ -76,18 +84,41 @@ let rec eval (context: EvaluationContext) (expr: Expr) =
                     | Some version -> Value.String version
                     | _ -> TerrabuildException.Raise($"Unknown project reference '{str}'")
 
-                | Function.Format, values ->
-                    let formatValue v =
-                        match v with
-                        | Value.Nothing -> ""
-                        | Value.Bool b -> if b then "true" else "false"
-                        | Value.Number n -> $"{n}"
-                        | Value.String s -> s
-                        | _ -> TerrabuildException.Raise($"Unsupported type for format {v}")
-
-                    values
-                    |> List.fold (fun acc value -> $"{acc}{formatValue value}") ""
-                    |> Value.String
+                | Function.ToString, [value] -> valueToString value |> Value.String
+
+                | Function.Format, [Value.String template; Value.Map values] ->
+                    let rec replaceAll template =
+                        match template with
+                        | String.Regex "{([^}]+)}" [name] ->
+                            let value =
+                                match values |> Map.tryFind name with
+                                | Some value -> valueToString value
+                                | _ -> TerrabuildException.Raise($"Field {name} does not exist")
+                            template
+                            |> String.replace $"{{{name}}}" value
+                            |> replaceAll
+                        | _ -> template
+
+                    replaceAll template |> Value.String
+
+                | Function.Format, Value.String template :: values ->
+                    let values = values |> List.map valueToString
+
+                    let rec replaceAll template =
+                        match template with
+                        | String.Regex "{([^}]+)}" [index] ->
+                            let value =
+                                match System.Int32.TryParse index with
+                                | (true, index) -> 
+                                    if 0 <= index && index < values.Length then values[index]
+                                    else TerrabuildException.Raise($"Format index is out of range")
+                                | _ -> TerrabuildException.Raise($"Format index is not a number")
+                            template
+                            |> String.replace $"{{{index}}}" value
+                            |> replaceAll
+                        | _ -> template
+
+                    replaceAll template |> Value.String
 
                 | Function.Item, [Value.Map map; Value.String key] ->
                     match map |> Map.tryFind key with

src/Terrabuild.Expressions/Expr.fs

@@ -11,6 +11,7 @@ type Function =
     | Count
     | Version
     | Format
+    | ToString
     | Item
     | TryItem
     | Coalesce