Merge 67d8fc0 into aff74fb

src/macros.jl

@@ -188,6 +188,15 @@ function parse_constraint(_error::Function, sense::Symbol, lhs, rhs)
     (sense, vectorized) = _check_vectorized(sense)
     vectorized, parse_one_operator_constraint(_error, vectorized, Val(sense), lhs, rhs)...
 end
+function parse_constraint(_error::Function, ::Val{:call}, args...)
+    return parse_constraint(_error, Val(args[1]), args[2:end]...)
+end
+
+function parse_constraint(_error::Function, sense::Val, F...)
+    sense_symbol = typeof(sense).parameters[1]
+    (sense, vectorized) = _check_vectorized(sense_symbol)
+    vectorized, parse_one_operator_constraint(_error, vectorized, Val(sense), F...)...
+end
 
 function parse_ternary_constraint(_error::Function, vectorized::Bool, lb, ::Union{Val{:(<=)}, Val{:(≤)}}, aff, rsign::Union{Val{:(<=)}, Val{:(≤)}}, ub)
     newaff, parseaff = _MA.rewrite(aff)
@@ -237,7 +246,16 @@ function parse_constraint_head(_error::Function, ::Val, args...)
     _unknown_constraint_expr(_error)
 end
 function parse_constraint(_error::Function, args...)
-    _unknown_constraint_expr(_error)
+    # Define this as the last fallback: either this is a function call that may
+    # be overridden by extensions, or a syntax that is not recognised.
+    # Multiple dispatch does not work here, due to ambiguity with:
+    #     parse_constraint(_error::Function, lb, lsign::Symbol, aff, rsign::Symbol, ub)
+    if args[1] isa Symbol
+        (sense, vectorized) = _check_vectorized(args[1])
+        vectorized, parse_one_operator_constraint(_error, vectorized, Val(sense), args[2:end]...)...
+    else
+        _unknown_constraint_expr(_error)
+    end
 end
 
 # Generic fallback.

test/macros.jl

@@ -176,6 +176,20 @@ function custom_expression_test(ModelType::Type{<:JuMP.AbstractModel})
     end
 end
 
+function JuMP.parse_one_operator_constraint(_error::Function, ::Bool, ::Val{:f}, x)
+    return :(), :(build_constraint($_error, $(esc(x)), $(esc(CustomType()))))
+end
+function custom_function_test(ModelType::Type{<:JuMP.AbstractModel})
+    @testset "Custom function" begin
+        model = ModelType()
+        @variable(model, x)
+        @constraint(model, con_ref, f(x))
+        con = JuMP.constraint_object(con_ref)
+        @test jump_function(con) == x
+        @test moi_set(con) isa CustomSet
+    end
+end
+
 function macros_test(ModelType::Type{<:JuMP.AbstractModel}, VariableRefType::Type{<:JuMP.AbstractVariableRef})
     @testset "build_constraint on variable" begin
         m = ModelType()
@@ -357,8 +371,8 @@ function macros_test(ModelType::Type{<:JuMP.AbstractModel}, VariableRefType::Typ
     end
 
     build_constraint_keyword_test(ModelType)
-
     custom_expression_test(ModelType)
+    custom_function_test(ModelType)
 end
 
 @testset "Macros for JuMP.Model" begin