avoid using Str when Strings suffices

src/core/pretty.ml

@@ -77,19 +77,16 @@ let forget_var vs = forget_id iprinter vs.vs_name
 
 let extract_op ls =
   let s = ls.ls_name.id_string in
-  let len = String.length s in
-  if len < 7 then None else
-  let inf = String.sub s 0 6 in
-  if inf = "infix "  then Some (String.sub s 6 (len - 6)) else
-  let prf = String.sub s 0 7 in
-  if prf = "prefix " then Some (String.sub s 7 (len - 7)) else
+  try Some (Strings.remove_prefix "infix " s) with Not_found ->
+  try Some (Strings.remove_prefix "prefix " s) with Not_found ->
   None
 
-let tight_op s = let c = String.sub s 0 1 in c = "!" || c = "?"
+let tight_op s =
+  s <> "" && (let c = String.get s 0 in c = '!' || c = '?')
 
 let escape_op s =
-  let s = Str.replace_first (Str.regexp "^\\*.") " \\0" s in
-  let s = Str.replace_first (Str.regexp ".\\*$") "\\0 " s in
+  let s = if Strings.has_prefix "*" s then " " ^ s else s in
+  let s = if Strings.ends_with s "*" then s ^ " " else s in
   s
 
 (* theory names always start with an upper case letter *)

src/mlw/expr.ml

@@ -1106,17 +1106,13 @@ let forget_let_defn = function
   | LDsym (s,_) -> forget_rs s
   | LDrec rdl -> List.iter (fun fd -> forget_rs fd.rec_sym) rdl
 
-let extract_op s =
-  let s = s.id_string in
-  let len = String.length s in
-  if len < 7 then None else
-  let inf = String.sub s 0 6 in
-  if inf = "infix "  then Some (String.sub s 6 (len - 6)) else
-  let prf = String.sub s 0 7 in
-  if prf = "prefix " then Some (String.sub s 7 (len - 7)) else
+let extract_op {id_string = s} =
+  try Some (Strings.remove_prefix "infix " s) with Not_found ->
+  try Some (Strings.remove_prefix "prefix " s) with Not_found ->
   None
 
-let tight_op s = let c = String.sub s 0 1 in c = "!" || c = "?"
+let tight_op s =
+  s <> "" && (let c = String.get s 0 in c = '!' || c = '?')
 
 let print_rs fmt ({rs_name = {id_string = nm}} as s) =
   if nm = "mixfix []" then pp_print_string fmt "([])" else
@@ -1127,8 +1123,8 @@ let print_rs fmt ({rs_name = {id_string = nm}} as s) =
   if nm = "mixfix [_.._]" then pp_print_string fmt "([_.._])" else
   match extract_op s.rs_name, s.rs_logic with
   | Some s, _ ->
-      let s = Str.replace_first (Str.regexp "^\\*.") " \\0" s in
-      let s = Str.replace_first (Str.regexp ".\\*$") "\\0 " s in
+      let s = if Strings.has_prefix "*" s then " " ^ s else s in
+      let s = if Strings.ends_with s "*" then s ^ " " else s in
       fprintf fmt "(%s)" s
   | _, RLnone | _, RLlemma ->
       pp_print_string fmt (id_unique sprinter s.rs_name)

src/mlw/vc.ml

@@ -109,8 +109,8 @@ let expl_loop_vari = Ident.create_label "expl:loop variant decrease"
 let expl_variant   = Ident.create_label "expl:variant decrease"
 let _expl_type_inv  = Ident.create_label "expl:type invariant"
 
-let lab_has_expl = let expl_regexp = Str.regexp "expl:" in
-  Slab.exists (fun l -> Str.string_match expl_regexp l.lab_string 0)
+let lab_has_expl lab =
+  Slab.exists (fun l -> Strings.has_prefix "expl:" l.lab_string) lab
 
 let vc_expl loc l ({t_label = lab} as f) =
   let lab = if lab_has_expl lab then lab else Slab.add l lab in

src/parser/parser.mly

@@ -25,47 +25,26 @@
   let model_label = Ident.create_label "model"
   let model_projected = Ident.create_label "model_projected"
 
-  let is_model_label l =
-    match l with
+  let is_model_label l = match l with
+    | Lstr lab -> Ident.lab_equal lab model_label ||
+                  Ident.lab_equal lab model_projected
     | Lpos _ -> false
-    | Lstr lab ->
-      (lab = model_label) || (lab = model_projected)
 
+  let model_lab_present labels = List.exists is_model_label labels
 
-  let model_lab_present labels =
-    try
-      ignore(List.find is_model_label labels);
-      true
-    with Not_found ->
-      false
-
-  let model_trace_regexp = Str.regexp "model_trace:"
-
-  let is_model_trace_label l =
-    match l with
+  let is_model_trace_label l = match l with
+    | Lstr lab -> Strings.has_prefix "model_trace:" lab.Ident.lab_string
     | Lpos _ -> false
-    | Lstr lab ->
-      try
-	ignore(Str.search_forward model_trace_regexp lab.Ident.lab_string 0);
-	true
-      with Not_found -> false
-
-  let model_trace_lab_present labels =
-    try
-      ignore(List.find is_model_trace_label labels);
-      true
-    with Not_found ->
-      false
+
+  let model_trace_lab_present labels = List.exists is_model_trace_label labels
 
   let add_model_trace name labels =
-    if (model_lab_present labels) && (not (model_trace_lab_present labels)) then
+    if model_lab_present labels && not (model_trace_lab_present labels) then
       (Lstr (Ident.create_label ("model_trace:" ^ name)))::labels
     else
       labels
 
-  let add_lab id l =
-    let l = add_model_trace id.id_str l in
-    { id with id_lab = l }
+  let add_lab id l = { id with id_lab = add_model_trace id.id_str l }
 
   let id_anonymous loc = { id_str = "_"; id_lab = []; id_loc = loc }
 

src/printer/smtv2.ml

@@ -205,18 +205,14 @@ let collect_model_ls info ls =
       add_model_element
       (t_label ?loc:ls.ls_name.id_loc ls.ls_name.id_label t) info.info_model
 
-let model_trace_regexp = Str.regexp "model_trace:"
+let model_trace_prefix = "model_trace:"
   (* The term labeled with "model_trace:name" will be in counter-example with name "name" *)
 
-let label_starts_with regexp l =
-  try
-    ignore(Str.search_forward regexp l.lab_string 0);
-    true
-  with Not_found -> false
-
-let get_label labels regexp =
-  Slab.choose (Slab.filter (label_starts_with regexp) labels)
+let get_label labels prefix =
+  let check l = Strings.has_prefix prefix l.lab_string in
+  Slab.choose (Slab.filter check labels)
 
+(* TODO: add "remove_suffix" to Strings and use it here instead of regexps *)
 let add_old lab_str =
   try
     let pos = Str.search_forward (Str.regexp "@") lab_str 0 in
@@ -234,7 +230,7 @@ let model_trace_for_postcondition ~labels info =
      model_trace label in a form function_name@result
   *)
   try
-    let trace_label = get_label labels model_trace_regexp in
+    let trace_label = get_label labels model_trace_prefix in
     let lab_str = add_old trace_label.lab_string in
     if lab_str = trace_label.lab_string then
       labels
@@ -271,7 +267,7 @@ let check_enter_vc_term t info =
     try
       (* Label "model_func" => the VC is postcondition or precondition *)
       (* Extract the function name from "model_func" label *)
-      let fun_label = get_label t.t_label (Str.regexp "model_func") in
+      let fun_label = get_label t.t_label "model_func:" in
       vc_term_info.vc_func_name <- Some (get_fun_name fun_label.lab_string);
     with Not_found ->
       (* No label "model_func" => the VC is not postcondition or precondition *)

src/transform/intro_vc_vars_counterexmp.ml

@@ -28,7 +28,7 @@ let model_vc_label = Ident.create_label "model_vc"
   (* Identifies the term that triggers the VC. *)
 let model_vc_post_label = Ident.create_label "model_vc_post"
 (* Identifies the postcondition that triggers the VC. *)
-let model_trace_regexp = Str.regexp "model_trace:"
+let model_trace_prefix = "model_trace:"
   (* The term labeled with "model_trace:name" will be in counterexample with name "name" *)
 
 (* Information about the term that triggers VC.  *)
@@ -41,17 +41,12 @@ type vc_term_info = {
   (* true if VC was generated for precondition or postcondition *)
 }
 
-let label_starts_with regexp l =
-  try
-    ignore(Str.search_forward regexp l.lab_string 0);
-    true
-  with Not_found -> false
-
-let get_label labels regexp =
-  Slab.choose (Slab.filter (label_starts_with regexp) labels)
+let get_label labels prefix =
+  let check l = Strings.has_prefix prefix l.lab_string in
+  Slab.choose (Slab.filter check labels)
 
-let is_model_vc_label l = if l = model_vc_label || l = model_vc_post_label then true
-  else false
+let is_model_vc_label l =
+  lab_equal l model_vc_label || lab_equal l model_vc_post_label
 
 let check_enter_vc_term t info =
   (* Check whether the term that triggers VC is entered.
@@ -71,6 +66,7 @@ let check_exit_vc_term t info =
     info.vc_inside <- false;
   end
 
+(* TODO: add "remove_suffix" to Strings and use it here instead of regexps *)
 let add_old lab_str =
   try
     let pos = Str.search_forward (Str.regexp "@") lab_str 0 in
@@ -89,7 +85,7 @@ let model_trace_for_postcondition ~labels =
      exist model_trace label in labels, labels otherwise.
   *)
   try
-    let trace_label = get_label labels model_trace_regexp in
+    let trace_label = get_label labels model_trace_prefix in
     let lab_str = add_old trace_label.lab_string in
     if lab_str = trace_label.lab_string then
       labels

src/util/strings.ml

@@ -73,7 +73,8 @@ let has_prefix pref s =
     with Exit -> false
 
 let remove_prefix pref s =
+  let sl = String.length s in
   let l = String.length pref in
-  if String.length s < l then raise Not_found else
+  if sl < l then raise Not_found else
   for i = 0 to l - 1 do if s.[i] <> pref.[i] then raise Not_found done;
-  String.sub s l (String.length s - l)
+  String.sub s l (sl - l)