Add a new macro @rulenode

Allows for convenient `RuleNode` construction
in the form `RuleNode`s are already printed in
(`1{2,3}` for `RuleNode(1, [RuleNode(2), RuleNode(3)]`)

Project.toml

@@ -1,7 +1,7 @@
 name = "HerbCore"
 uuid = "2b23ba43-8213-43cb-b5ea-38c12b45bd45"
 authors = ["Jaap de Jong <[email protected]>", "Nicolae Filat <[email protected]>", "Tilman Hinnerichs <[email protected]>", "Sebastijan Dumancic <[email protected]>"]
-version = "0.3.2"
+version = "0.3.3"
 
 [compat]
 julia = "^1.8"

src/HerbCore.jl

@@ -7,6 +7,7 @@ include("grammar.jl")
 export
        AbstractRuleNode,
        RuleNode,
+       @rulenode,
        AbstractHole,
        AbstractUniformHole,
        UniformHole,

src/rulenode.jl

@@ -91,6 +91,47 @@ Create a [`RuleNode`](@ref) for the [`AbstractGrammar`](@ref) rule with index `i
 """
 RuleNode(ind::Int, children::Vector{<:AbstractRuleNode}) = RuleNode(ind, nothing, children)
 
+function _shorthand2rulenode(i::Integer)
+    :(RuleNode($i))
+end
+
+function _shorthand2rulenode(ex::Expr)
+    @assert ex.head==:curly "Input to the @rulenode macro should be in the form of: 1{2,3}"
+    :(RuleNode(
+        # Interpolate the _value_ of the first rule (1 from 1{2,3})
+        # into the first argument of the RuleNode constructor
+        $(ex.args[1]),
+        [
+        # Fill in the array of children recursively with the contents of the
+        # curly brackets (2 and 3 from 1{2,3})
+            $([_shorthand2rulenode(child) for child in ex.args[2:end]]...)
+        ]
+    ))
+end
+
+"""
+    @rulenode 
+
+Construct a [`RuleNode`](@ref) using the shorthand notation [`RuleNode`](@ref)s are printed
+with using [`Base.show`](@ref). Does not support [`AbstractHole`](@ref)s.
+
+# Examples
+
+```jldoctest
+julia> @rulenode 1{4{5,6},1{2,3}}
+1{4{5,6},1{2,3}}
+
+julia> @rulenode 1
+1
+
+julia> @rulenode 1{2, 3}
+1{2,3}
+```
+"""
+macro rulenode(ex::Union{Integer, Expr})
+    _shorthand2rulenode(ex)
+end
+
 """
     RuleNode(ind::Int, _val::Any)
 

test/runtests.jl

@@ -259,6 +259,23 @@ using Test
             @test hasdynamicvalue(Hole(BitVector((1, 0)))) == false
         end
 
+        @testset "@rulenode" begin
+            node = @rulenode 1{2, 3}
+            children = get_children(node)
+            @test get_rule(node) == 1
+            @test get_rule(children[1]) == 2
+            @test get_rule(children[2]) == 3
+
+            node = @rulenode 1
+            children = get_children(node)
+            @test get_rule(node) == 1
+            @test isempty(children)
+
+            node = @rulenode 1{4{5, 6}, 1{2, 3}}
+            @test get_rule(node) == 1
+            @test depth(node) == 3
+        end
+
         @testset "show" begin
             node = RuleNode(1, [RuleNode(1), RuleNode(2), RuleNode(3)])
             io = IOBuffer()