Fix EBNF to BNF conversion bug.

Expression trees with identical contents were not hashed identically.
This meant that dictionary keyed by Tree did not recognise when
a tree was already present.

src/load_grammar.jl

@@ -147,7 +147,7 @@ const RULES = Dict(
 
 mutable struct EBNF_to_BNF <: Transformer_InPlace
     new_rules::Array{Tuple{String,Tree,Any}}
-    rules_by_expr::Dict{Union{String,LarkSymbol,Tree},NonTerminal}
+    rules_by_expr::Dict{Union{String,LarkSymbol,Tree}, NonTerminal}
     prefix::String
     i::Int
     rule_options::Union{Nothing,RuleOptions}
@@ -640,7 +640,10 @@ compile(g::Grammar, start, terminals_to_keep) = begin
         ebnf_to_bnf.prefix = name
         anon_tokens_transf.rule_options = rule_options
         tree = transform(transformer,rule_tree)
-        push!(rules,(name, transform(ebnf_to_bnf,tree), options))
+        @debug "After anon transf" name tree
+        res = transform(ebnf_to_bnf,tree)
+        @debug "After bnf transf" res
+        push!(rules,(name, res, options))
     end
 
     append!(rules, ebnf_to_bnf.new_rules)

src/parsers/grammar_analysis.jl

@@ -218,9 +218,11 @@ expand_rule(g::GrammarAnalyzer,source_rule, rules_by_origin=nothing) = begin
     _expand_rule(_rule) = begin
         Channel() do rule_chan
             #@assert !_rule.is_term _rule
+            @debug "Expanding" _rule
             for r in rules_by_origin[_rule]
                 init_ptr = RulePtr(r,0)
                 push!(init_ptrs,init_ptr)
+                @debug "Added rule" init_ptr
 
                 if !isempty(r.expansion)
                     # Next symbol from this
@@ -236,5 +238,6 @@ expand_rule(g::GrammarAnalyzer,source_rule, rules_by_origin=nothing) = begin
 
     _ = collect(bfs([source_rule], _expand_rule))
 
+    @debug "Final rules after expansion" init_ptrs
     return init_ptrs
 end

src/parsers/lalr_analysis.jl

@@ -177,8 +177,11 @@ compute_lr0_states(l::LALR_Analyzer) = begin
         end
         push!(l.lr0_states,state)
     end
+    @debug "Number of lr0 start states" length(l.lr0_start_states)
+    @debug "Start states: $(l.lr0_start_states)"
     collect(bfs(values(l.lr0_start_states),step))
-    #println("lr0_states after: $(l.lr0_states)")
+    @debug "Number of lr0 states" length(l.lr0_states)
+    @debug "lr0_states after:" l.lr0_states
 end
 
 compute_reads_relations(l::LALR_Analyzer) = begin
@@ -294,22 +297,26 @@ end
 compute_lalr1_states(l::LALR_Analyzer) = begin
     m = IdDict{LR0ItemSet,IdDict{String,Tuple{Symbol,Union{Set{RulePtr},Rule}}}}()
     reduce_reduce = []
+    @debug "Have $(length(l.lr0_states)) states"
     for state in l.lr0_states
         actions = IdDict{LarkSymbol,Tuple{Symbol,Union{Set{RulePtr},Rule}}}()
         for (la, next_state) in state.transitions
             actions[la] = (:shift, next_state.closure)
         end
 
         for (la, rules) in state.lookaheads
+            @debug "State" state
             if length(rules) > 1
                 # Try to resolve conflict based on priority
                 p = [(r.options.priority !== nothing ? r.options.priority : 0, r) for r in rules]
                 sort!(p,by=r -> r[1], rev=true)
                 best, second_best = p[1:2]
+                @debug "Conflict:" state la p
                 if best[1] > second_best[1]
                     rules = [best[2]]
                 else
                     push!(reduce_reduce,(state, la, rules))
+                    @debug "Reduce/reduce conflict" reduce_reduce[end]
                 end
             end
             if la in keys(actions)

src/tree.jl

@@ -106,8 +106,12 @@ end
 end
 ==#
 
-Base.hash(t1::Tree) = begin
-    return hash(t1.data,hash(t1.children))
+Base.hash(t1::Tree,h::UInt) = begin
+    h = hash(t1.data,h)
+    for t in t1.children
+        h = hash(t, h)
+    end
+    return h
 end
 
 find_pred(t::Tree,pred) = begin