From 670de54bd219fffcb54ee2a2e2d7edff44c956ff Mon Sep 17 00:00:00 2001
From: Sasha Demin <ademin@mpi-inf.mpg.de>
Date: Tue, 3 Oct 2023 01:49:29 +0200
Subject: [PATCH] take variable names seriously

---
 src/parametrizations.jl         | 10 ++++-----
 src/util.jl                     | 36 +++++++++++++++++++++++++++++++++
 test/constructive_membership.jl | 11 ++++++++++
 3 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/src/parametrizations.jl b/src/parametrizations.jl
index 39ab8705f..0023f8f0d 100644
--- a/src/parametrizations.jl
+++ b/src/parametrizations.jl
@@ -165,9 +165,9 @@ function check_constructive_field_membership(
         @assert length(fracs_gen) == length(tag_names)
         tag_names
     else
-        map(i -> "T$i", 1:length(fracs_gen))
+        gen_tag_names(length(fracs_gen), "Tag")
     end
-    sat_string = "_t"
+    sat_string = gen_tag_name("Sat")
     @info """
     Tags:
     $(join(map(x -> string(x[1]) * " -> " * string(x[2]),  zip(fracs_gen, tag_strings)), "\t\n"))
@@ -318,9 +318,9 @@ function reparametrize_with_respect_to(ode, new_states, new_params)
     n_active_generators =
         (length(generating_funcs) - length(ode.u_vars) - length(ode.y_vars))
     tag_names = vcat(
-        ["_T$i" for i in 1:n_active_generators],
-        map(v -> "_$(uppercase(string(v)))", ode.u_vars),
-        map(v -> "_$(uppercase(string(v)))", ode.y_vars),
+        gen_tag_names(n_active_generators, "Internal"),
+        gen_tag_names(length(ode.u_vars), "Input"),
+        gen_tag_names(length(ode.y_vars), "Output"),
     )
     @info """
     Tag names: 
diff --git a/src/util.jl b/src/util.jl
index 068780c54..474c73d32 100644
--- a/src/util.jl
+++ b/src/util.jl
@@ -408,6 +408,42 @@ end
 
 # ------------------------------------------------------------------------------
 
+"""
+    gen_tag_name(base; stop_words)
+    gen_tag_names(n, base; stop_words)
+
+Generates a string which will not collide with the words in `stop_words`.
+
+## Arguments
+
+- `n`: Generates a sequence of unique strings of length `n`
+- `base`: A string or a vector of strings, the base for the generated sequence
+- `stop_words`: A vector of strings, stop words
+"""
+function gen_tag_name(base = "T"; stop_words = Vector{String}())
+    return first(gen_tag_names(1, base, stop_words = stop_words))
+end
+
+function gen_tag_names(n::Integer, base = "T"; stop_words = Vector{String}())
+    sequence = if base isa Vector{String}
+        @assert n == length(base)
+        base
+    else
+        repeat([base], n)
+    end
+    while true
+        rand_token = Int(rand(UInt8))
+        sequence = map(c -> "$(rand_token)__$c", sequence)
+        sequence = map(ic -> "$(ic[2])_$(ic[1])", enumerate(sequence))
+        if all(elem -> !(elem in stop_words), sequence)
+            break
+        end
+    end
+    return sequence
+end
+
+# ------------------------------------------------------------------------------
+
 """
     switch_ring(v, ring)
 
diff --git a/test/constructive_membership.jl b/test/constructive_membership.jl
index 927579d09..d80aca25f 100644
--- a/test/constructive_membership.jl
+++ b/test/constructive_membership.jl
@@ -8,6 +8,7 @@
         StructuralIdentifiability.check_constructive_field_membership(
             StructuralIdentifiability.RationalFunctionField(generators),
             map(f -> f // one(f), to_be_reduced),
+            tag_names = ["T1", "T2"],
         )
     tags = gens(base_ring(parent(first(remainders))))
 
@@ -26,6 +27,16 @@
         [(generators = [T1^2], to_be_reduced = [T1, T1^2], memberships = Bool[0, 1])],
     )
 
+    R, (T1, t, _t) = PolynomialRing(Nemo.QQ, ["T1", "t", "_t"])
+    append!(
+        cases,
+        [(
+            generators = [T1, t, _t],
+            to_be_reduced = [_t, t, T1 * t * _t],
+            memberships = Bool[1, 1, 1],
+        )],
+    )
+
     R, (x,) = PolynomialRing(Nemo.QQ, ["x"])
     append!(
         cases,