Add 'len <expr>' operator.

[whenjobs.git] / lib / whenexpr.ml

diff --git a/lib/whenexpr.ml b/lib/whenexpr.ml
index f24e9ed..8ccde2c 100644 (file)
--- a/lib/whenexpr.ml
+++ b/lib/whenexpr.ml
@@ -47,6 +47,7 @@ type whenexpr =
   | Expr_mul of whenexpr * whenexpr
   | Expr_div of whenexpr * whenexpr
   | Expr_mod of whenexpr * whenexpr
+  | Expr_len of whenexpr
   | Expr_changes of string
   | Expr_increases of string
   | Expr_decreases of string
@@ -202,6 +203,9 @@ and expr_of_iexpr _loc = function
   | IExpr_app ("mod", exprs) ->
     two_params _loc "+" exprs (fun e1 e2 -> Expr_mod (e1, e2))
 
+  | IExpr_app (("len"|"length"|"size"), exprs) ->
+    one_param _loc "len" exprs (fun e1 -> Expr_len e1)
+
   | IExpr_app (("change"|"changes"|"changed"), [IExpr_var v]) ->
     Expr_changes v
 
@@ -274,6 +278,7 @@ let rec string_of_whenexpr = function
     sprintf "%s / %s" (string_of_whenexpr e1) (string_of_whenexpr e2)
   | Expr_mod (e1, e2) ->
     sprintf "%s mod %s" (string_of_whenexpr e1) (string_of_whenexpr e2)
+  | Expr_len e -> sprintf "len %s" (string_of_whenexpr e)
   | Expr_changes v -> sprintf "changes %s" v
   | Expr_increases v -> sprintf "increases %s" v
   | Expr_decreases v -> sprintf "decreases %s" v
@@ -310,7 +315,8 @@ let rec dependencies_of_whenexpr = function
   | Expr_div (e1, e2)
   | Expr_mod (e1, e2) ->
     dependencies_of_whenexpr e1 @ dependencies_of_whenexpr e2
-  | Expr_not e ->
+  | Expr_not e
+  | Expr_len e ->
     dependencies_of_whenexpr e
   | Expr_changes v
   | Expr_increases v
@@ -417,6 +423,11 @@ let rec eval_whenexpr variables prev_variables onload = function
     and e2 = eval_whenexpr variables prev_variables onload e2 in
     mod_values e1 e2
 
+  | Expr_len e ->
+    let e = eval_whenexpr variables prev_variables onload e in
+    let e = string_of_variable e in
+    T_int (big_int_of_int (String.length e))
+
   | Expr_changes v ->
     let prev_value, curr_value = get_prev_curr_value variables prev_variables v in
     if compare_values prev_value curr_value <> 0 then