Update docs and samples for int/string map keys

Author: pchalamet

docs/embedding-fscript-language.md

@@ -141,7 +141,7 @@ Host-visible static types are represented by `Type`:
 - `TList of Type`
 - `TTuple of Type list`
 - `TRecord of Map<string, Type>`
-- `TStringMap of Type`
+- `TMap of Type * Type`
 - `TOption of Type`
 - `TFun of Type * Type`
 - `TNamed of string`
@@ -150,6 +150,7 @@ Host-visible static types are represented by `Type`:
 - `TVar of int`
 
 Use `Types.typeToString` for display/diagnostics.
+The postfix script type syntax `'a map` corresponds to `TMap(TString, 'a)`.
 
 ## Runtime values
 
@@ -163,7 +164,7 @@ Evaluation returns `Value`:
 - `VList of Value list`
 - `VTuple of Value list`
 - `VRecord of Map<string, Value>`
-- `VStringMap of Map<string, Value>`
+- `VMap of Map<MapKey, Value>`
 - `VOption of Value option`
 - `VUnionCase of string * string * Value option`
 - `VUnionCtor of string * string`

docs/language-choices.md

@@ -21,6 +21,7 @@ let x =
   - `'a map`
 - Map values use native literals:
   - `{ ["a"] = 1; ["b"] = 2 }`
+  - `{ [1] = "one"; [2] = "two" }`
 - Map update/merge is available directly in literals:
   - `{ ["a"] = 1; ..tail }`
 - Function types use arrow syntax:
@@ -55,6 +56,7 @@ let x =
 - Typed decoding workflows use `typeof Name` tokens with host externs.
 - Capability maps can use `nameof identifier` for stable script-side function keys.
 - Capability maps use string keys in map literals (`[expr]` where `expr : string`).
+- Maps also support integer keys (`[expr]` where `expr : int`) for numeric indexing scenarios.
 
 ## Formatting and layout choices
 - `match` case columns align.

docs/supported-types.md

@@ -14,17 +14,18 @@ This document specifies the value and type system used by the interpreter.
 - List: `'a list`
 - Tuple: `(t1 * t2 * ...)`
 - Option: `'a option`
-- String-keyed map: `'a map`
+- Map (string-keyed alias): `'a map`
 - Record: structural record types
 - Discriminated union: named union types with cases
 
 ## Map literals
 - Native map literal syntax:
   - empty: `{}`
   - populated: `{ ["a"] = 1; ["b"] = 2 }`
+  - int keys: `{ [1] = "one"; [2] = "two" }`
   - spread update: `{ ["a"] = 1; ..tail }`
   - multiline entries are supported in an indented block.
-- Keys are bracketed expressions and must have type `string` (for example `{ [keyExpr] = value }`).
+- Keys are bracketed expressions and must have type `string` or `int` (for example `{ [keyExpr] = value }`).
 - Record literals and map literals share `{ ... }` braces:
   - map entries use `[expr] = value`
   - record entries use `Field = value`
@@ -76,7 +77,7 @@ This document specifies the value and type system used by the interpreter.
 - `VUnit`, `VInt`, `VFloat`, `VBool`, `VString`
 - `VList`, `VTuple`
 - `VRecord`
-- `VStringMap`
+- `VMap`
 - `VOption`
 - `VUnionCase`, `VUnionCtor`
 - `VClosure`

docs/syntax-and-indentation.md

@@ -38,6 +38,7 @@ This document describes the concrete syntax accepted by the interpreter and the
   - record patterns in cases: `{ Field = pattern; ... }`
   - map patterns in cases support keyed lookup and extraction:
     - keyed lookup: `{ ["key"] = v }`
+    - int-key lookup: `{ [1] = v }`
     - multiple keys: `{ ["a"] = x; ["b"] = y }`
     - optional tail capture: `{ ["a"] = x; ..tail }`
     - dynamic extraction (preserved): `{ [k] = v; ..tail }`
@@ -57,11 +58,12 @@ This document describes the concrete syntax accepted by the interpreter and the
 - Maps:
   - empty `{}`
   - literal `{ ["a"] = 1; ["b"] = 2 }`
+  - int-key literal `{ [1] = "one"; [2] = "two" }`
   - update/merge with spread `{ ["a"] = 1; ..tail }`
   - map entries always use bracketed keys (`[expr] = value`)
   - record entries use field assignments (`Field = value`)
   - when braces are empty (`{}`), the literal is a map
-  - keys are bracketed expressions (`[expr]`) and must infer to `string`
+  - keys are bracketed expressions (`[expr]`) and must infer to `string` or `int`
   - if entries start on the next line, `{` must be on its own line
   - multiline example:
   ```fsharp

samples/map-matching.fss

@@ -4,6 +4,11 @@ let values =
       ["beta"] = 20
       ["gamma"] = 30 }
 
+let indexed =
+    { [1] = "one"
+      [2] = "two"
+      [3] = "three" }
+
 match values with
 | { ["alpha"] = v1; ..tail } ->
     print $"alpha={v1}; tail={tail}"
@@ -18,3 +23,8 @@ match values with
 | { [k] = v; ..tail } ->
     print $"dynamic extraction: {k} = {v}, tail={tail}"
 | _ -> print "no dynamic match"
+
+match indexed with
+| { [1] = first; [2] = second; ..tail } ->
+    print $"int-key match: first={first}, second={second}, tail={tail}"
+| _ -> print "no int-key match"

samples/types-showcase.fss

@@ -22,6 +22,9 @@ type Subscription =
 let scores =
     { ["math"] = 20; ["science"] = 18 }
 
+let statusByCode =
+    { [200] = "ok"; [404] = "not-found" }
+
 
 let user = { Id = 1; Name = "Ada"; Tags = ["engineer"; "writer"]; Address = Some { City = "London"; Zip = 12345 }; Scores = scores; Pair = (7, "seven") }
 let subscription = Premium 12
@@ -75,6 +78,7 @@ let monthlyPrice =
     | Premium amount -> amount
 
 let missing = "missing"
+let unknown = "unknown"
 
 print $"User: {updated.Name}"
 print $"City: {city}"
@@ -90,6 +94,7 @@ print $"Subscription price: {monthlyPrice}"
 print $"Structural address from literal: {format_address parisAddress}"
 print $"Structural address from OfficeAddress: {format_address officeAddress}"
 print $"Capability for format_address: {Map.tryGet formatAddressKey capabilities |> Option.defaultValue missing}"
+print $"HTTP 200: {statusByCode[200] |> Option.defaultValue unknown}"
 
 
 updated.Tags |> List.iter print