Commit 6b911f1e94

Andrew Kelley <superjoe30@gmail.com>
2015-11-24 03:21:52
delete parser generator. let's try recursive descent
1 parent 5b663dd
src/parser.cpp
@@ -79,8 +79,13 @@ void ast_print(AstNode *node, int indent) {
     }
 }
 
-AstNode *ast_create_root(Token *token) {
-    return nullptr;
+struct ParseContext {
+    Buf *buf;
+    AstNode *root;
+};
+
+AstNode *ast_create_root(void) {
+    zig_panic("TODO create root");
 }
 
 void ast_invalid_token_error(Buf *buf, Token *token) {
@@ -88,3 +93,17 @@ void ast_invalid_token_error(Buf *buf, Token *token) {
     buf_init_from_mem(&token_value, buf_ptr(buf) + token->start_pos, token->end_pos - token->start_pos);
     ast_error(token, "invalid token: '%s'", buf_ptr(&token_value));
 }
+
+void ast_parse_fn_decls(ParseContext *pc, ZigList<AstNode *> *fn_decls) {
+    zig_panic("TODO parse fn decls");
+}
+
+AstNode *ast_parse(Buf *buf, ZigList<Token> *tokens) {
+    ParseContext pc = {0};
+    pc.buf = buf;
+    pc.root = ast_create_root();
+
+    ast_parse_fn_decls(&pc, &pc.root->data.root.fn_decls);
+
+    return pc.root;
+}
src/parser.hpp
@@ -91,6 +91,6 @@ const char *node_type_str(NodeType node_type);
 
 void ast_print(AstNode *node, int indent);
 
-AstNode *ast_create_root(Token *token);
+AstNode *ast_create_root(void);
 
 #endif
src/parsergen.cpp
@@ -1,1125 +0,0 @@
-/*
- * Copyright (c) 2015 Andrew Kelley
- *
- * This file is part of zig, which is MIT licensed.
- * See http://opensource.org/licenses/MIT
- */
-
-#include "util.hpp"
-#include "buffer.hpp"
-#include "list.hpp"
-
-#include <stdio.h>
-#include <stdarg.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <errno.h>
-#include <limits.h>
-
-#define WHITESPACE \
-    ' ': \
-    case '\t': \
-    case '\n': \
-    case '\f': \
-    case '\r': \
-    case 0xb
-
-#define DIGIT \
-    '0': \
-    case '1': \
-    case '2': \
-    case '3': \
-    case '4': \
-    case '5': \
-    case '6': \
-    case '7': \
-    case '8': \
-    case '9'
-
-#define LOWER_ALPHA \
-    'a': \
-    case 'b': \
-    case 'c': \
-    case 'd': \
-    case 'e': \
-    case 'f': \
-    case 'g': \
-    case 'h': \
-    case 'i': \
-    case 'j': \
-    case 'k': \
-    case 'l': \
-    case 'm': \
-    case 'n': \
-    case 'o': \
-    case 'p': \
-    case 'q': \
-    case 'r': \
-    case 's': \
-    case 't': \
-    case 'u': \
-    case 'v': \
-    case 'w': \
-    case 'x': \
-    case 'y': \
-    case 'z'
-
-#define UPPER_ALPHA \
-    'A': \
-    case 'B': \
-    case 'C': \
-    case 'D': \
-    case 'E': \
-    case 'F': \
-    case 'G': \
-    case 'H': \
-    case 'I': \
-    case 'J': \
-    case 'K': \
-    case 'L': \
-    case 'M': \
-    case 'N': \
-    case 'O': \
-    case 'P': \
-    case 'Q': \
-    case 'R': \
-    case 'S': \
-    case 'T': \
-    case 'U': \
-    case 'V': \
-    case 'W': \
-    case 'X': \
-    case 'Y': \
-    case 'Z'
-
-#define ALPHA \
-    LOWER_ALPHA: \
-    case UPPER_ALPHA
-
-#define SYMBOL_CHAR \
-    ALPHA: \
-    case DIGIT: \
-    case '_'
-
-static Buf *fetch_file(FILE *f) {
-    int fd = fileno(f);
-    struct stat st;
-    if (fstat(fd, &st))
-        zig_panic("unable to stat file: %s", strerror(errno));
-    off_t big_size = st.st_size;
-    if (big_size > INT_MAX)
-        zig_panic("file too big");
-    int size = (int)big_size;
-
-    Buf *buf = buf_alloc_fixed(size);
-    size_t amt_read = fread(buf_ptr(buf), 1, buf_len(buf), f);
-    if (amt_read != (size_t)buf_len(buf))
-        zig_panic("error reading: %s", strerror(errno));
-
-    return buf;
-}
-
-static int usage(const char *arg0) {
-    fprintf(stderr, "Usage: %s in-grammar.txt out-parser.c\n", arg0);
-    return 1;
-}
-
-struct Token {
-    Buf name;
-    int id;
-};
-
-struct RuleNode;
-
-struct RuleTuple {
-    ZigList<RuleNode *> children;
-    Buf body;
-};
-
-struct RuleMany {
-    RuleNode *child;
-};
-
-struct RuleOr {
-    Buf name;
-    Buf union_field_name;
-    ZigList<RuleNode *> children;
-};
-
-struct RuleToken {
-    Token *token;
-};
-
-struct RuleList {
-    RuleNode *rule;
-    RuleToken *separator;
-};
-
-struct RuleSubRule {
-    RuleNode *child;
-
-    // for lexer use only
-    Buf name;
-};
-
-enum RuleNodeType {
-    RuleNodeTypeTuple,
-    RuleNodeTypeMany,
-    RuleNodeTypeList,
-    RuleNodeTypeOr,
-    RuleNodeTypeToken,
-    RuleNodeTypeSubRule,
-};
-
-struct RuleNode {
-    RuleNodeType type;
-    int lex_line;
-    int lex_column;
-    union {
-        RuleTuple tuple;
-        RuleMany many;
-        RuleList list;
-        RuleOr _or;
-        RuleToken token;
-        RuleSubRule sub_rule;
-    };
-};
-
-
-enum CodeGenType {
-    CodeGenTypeTransition,
-    CodeGenTypeError,
-    CodeGenTypeSave,
-    CodeGenTypePushNode,
-    CodeGenTypeCapture,
-    CodeGenTypePopNode,
-    CodeGenTypeEatToken,
-};
-
-struct CodeGenError {
-    Buf *msg;
-};
-
-struct CodeGenCapture {
-    Buf *body;
-    bool is_root;
-    Buf *field_names;
-    Buf *union_field_name;
-};
-
-struct CodeGen {
-    CodeGenType type;
-    union {
-        CodeGenError error;
-        CodeGenCapture capture;
-    };
-};
-
-struct ParserState {
-    ZigList<CodeGen *> code_gen_list;
-    // One for each token ID.
-    ParserState **transition;
-    int index;
-    bool is_error;
-};
-
-enum LexState {
-    LexStateStart,
-    LexStateRuleName,
-    LexStateRuleFieldNameStart,
-    LexStateRuleFieldName,
-    LexStateWaitForColon,
-    LexStateTupleRule,
-    LexStateFnName,
-    LexStateTokenStart,
-    LexStateToken,
-    LexStateBody,
-    LexStateEndOrOr,
-    LexStateSubTupleName,
-};
-
-struct LexStack {
-    LexState state;
-};
-
-struct Gen {
-    ZigList<RuleNode *> rules;
-
-    ZigList<ParserState *> transition_table;
-    ParserState *start_state;
-    ZigList<Token *> tokens;
-    RuleNode *root;
-    int biggest_tuple_len;
-
-    Buf *in_buf;
-    LexState lex_state;
-    int lex_line;
-    int lex_column;
-    RuleNode *lex_cur_or_rule;
-    RuleNode *lex_cur_tuple_rule;;
-    int lex_cur_rule_begin;
-    int lex_fn_name_begin;
-    int lex_pos;
-    ZigList<LexStack> lex_stack;
-    int lex_token_name_begin;
-    int lex_body_begin;
-    int lex_body_end;
-    int lex_sub_tuple_begin;
-    int lex_field_name_begin;
-};
-
-static ParserState *create_state(Gen *g) {
-    ParserState *state = allocate<ParserState>(1);
-    state->index = -1;
-    state->transition = allocate<ParserState*>(g->tokens.length);
-    return state;
-}
-
-static void fill_state_with_transition(Gen *g, ParserState *source, ParserState *dest) {
-    for (int i = 0; i < g->tokens.length; i += 1) {
-        source->transition[i] = dest;
-    }
-}
-
-static void state_add_code(ParserState *state, CodeGen *code) {
-    state->code_gen_list.append(code);
-}
-
-static void state_add_save_token(ParserState *state) {
-    CodeGen *code = allocate<CodeGen>(1);
-    code->type = CodeGenTypeSave;
-    state_add_code(state, code);
-}
-
-static void state_add_error(ParserState *state, Buf *msg) {
-    CodeGen *code = allocate<CodeGen>(1);
-    code->type = CodeGenTypeError;
-    code->error.msg = msg;
-    state_add_code(state, code);
-    state->is_error = true;
-}
-
-static void state_add_transition(ParserState *state) {
-    CodeGen *code = allocate<CodeGen>(1);
-    code->type = CodeGenTypeTransition;
-    state_add_code(state, code);
-}
-
-static void state_add_push_node(ParserState *state) {
-    CodeGen *code = allocate<CodeGen>(1);
-    code->type = CodeGenTypePushNode;
-    state_add_code(state, code);
-}
-
-static CodeGen *codegen_create_capture(Buf *body, bool is_root, int field_name_count, Buf *union_field_name) {
-    CodeGen *code = allocate<CodeGen>(1);
-    code->type = CodeGenTypeCapture;
-    code->capture.body = body;
-    code->capture.is_root = is_root;
-    code->capture.field_names = allocate<Buf>(field_name_count);
-    code->capture.union_field_name = union_field_name;
-    return code;
-}
-
-static void state_add_pop_node(ParserState *state) {
-    CodeGen *code = allocate<CodeGen>(1);
-    code->type = CodeGenTypePopNode;
-    state_add_code(state, code);
-}
-
-static void state_add_eat_token(ParserState *state) {
-    CodeGen *code = allocate<CodeGen>(1);
-    code->type = CodeGenTypeEatToken;
-    state_add_code(state, code);
-}
-
-
-static void gen(Gen *g, RuleNode *node, Buf *out_field_name, ParserState *cur_state,
-        ZigList<ParserState *> *end_states, bool is_root)
-{
-    struct PossibleState {
-        ParserState *test_state;
-        ZigList<ParserState *> end_states;
-    };
-    assert(node);
-    switch (node->type) {
-        case RuleNodeTypeToken:
-            {
-                buf_init_from_str(out_field_name, "token");
-
-                state_add_save_token(cur_state);
-
-                ParserState *ok_state = create_state(g);
-                ParserState *err_state = create_state(g);
-                state_add_error(err_state, buf_sprintf("expected token '%s'", buf_ptr(&node->token.token->name)));
-
-                fill_state_with_transition(g, cur_state, err_state);
-                cur_state->transition[node->token.token->id] = ok_state;
-                state_add_transition(cur_state);
-                state_add_eat_token(cur_state);
-
-                end_states->append(ok_state);
-            }
-            break;
-        case RuleNodeTypeTuple:
-            {
-
-                int field_name_count = node->tuple.children.length;
-                CodeGen *code = codegen_create_capture(&node->tuple.body, is_root, field_name_count,
-                        out_field_name);
-
-                ZigList<ParserState *> *my_end_states = allocate<ZigList<ParserState *>>(1);
-                my_end_states->append(cur_state);
-                for (int child_index = 0; child_index < node->tuple.children.length; child_index += 1) {
-                    RuleNode *child = node->tuple.children.at(child_index);
-
-                    ZigList<ParserState *> *more_end_states = allocate<ZigList<ParserState *>>(1);
-                    for (int i = 0; i < my_end_states->length; i += 1) {
-                        ParserState *use_state = my_end_states->at(i);
-                        gen(g, child, &code->capture.field_names[i], use_state, more_end_states, false);
-                    }
-
-                    my_end_states = more_end_states;
-                }
-
-                for (int i = 0; i < my_end_states->length; i += 1) {
-                    ParserState *use_state = my_end_states->at(i);
-                    state_add_code(use_state, code);
-
-                    end_states->append(use_state);
-                }
-            }
-            break;
-        case RuleNodeTypeMany:
-            zig_panic("TODO");
-            break;
-        case RuleNodeTypeList:
-            zig_panic("TODO");
-            break;
-        case RuleNodeTypeOr:
-            {
-                buf_init_from_buf(out_field_name, &node->_or.union_field_name);
-
-                state_add_push_node(cur_state);
-
-                // TODO this probably need to get moved when or can handle conflicts
-                state_add_save_token(cur_state);
-                state_add_transition(cur_state);
-                state_add_eat_token(cur_state);
-
-
-                int possible_state_count = node->_or.children.length;
-                PossibleState *possible_states = allocate<PossibleState>(possible_state_count);
-                for (int i = 0; i < possible_state_count; i += 1) {
-                    RuleNode *child = node->_or.children.at(i);
-                    assert(child->type == RuleNodeTypeTuple);
-
-                    PossibleState *possible_state = &possible_states[i];
-                    possible_state->test_state = create_state(g);
-                    gen(g, child, &node->_or.union_field_name, possible_state->test_state,
-                            &possible_state->end_states, is_root);
-                }
-
-                // try to merge all the possible states into new state.
-                ParserState *err_state = create_state(g);
-                state_add_error(err_state, buf_create_from_str("unexpected token"));
-                for (int token_i = 0; token_i < g->tokens.length; token_i += 1) {
-                    bool any_called_it = false;
-                    bool conflict = false;
-                    for (int state_i = 0; state_i < possible_state_count; state_i += 1) {
-                        PossibleState *possible_state = &possible_states[state_i];
-                        if (!possible_state->test_state->transition[token_i]->is_error) {
-                            if (any_called_it) {
-                                conflict = true;
-                            } else {
-                                any_called_it = true;
-                            }
-                        }
-                    }
-                    if (conflict) {
-                        zig_panic("TODO state transition conflict");
-                    } else {
-                        cur_state->transition[token_i] = err_state;
-                        for (int state_i = 0; state_i < possible_state_count; state_i += 1) {
-                            PossibleState *possible_state = &possible_states[state_i];
-                            if (!possible_state->test_state->transition[token_i]->is_error) {
-                                cur_state->transition[token_i] = possible_state->test_state->transition[token_i];
-                            }
-                        }
-                    }
-                }
-
-                for (int state_i = 0; state_i < possible_state_count; state_i += 1) {
-                    PossibleState *possible_state = &possible_states[state_i];
-                    for (int end_i = 0; end_i < possible_state->end_states.length; end_i += 1) {
-                        ParserState *state = possible_state->end_states.at(end_i);
-                        state_add_pop_node(state);
-
-                        end_states->append(state);
-                    }
-                }
-            }
-            break;
-        case RuleNodeTypeSubRule:
-            {
-                RuleNode *child = node->sub_rule.child;
-                gen(g, child, out_field_name, cur_state, end_states, false);
-            }
-            break;
-    }
-}
-
-static Token *find_token_by_name(Gen *g, Buf *name) {
-    for (int i = 0; i < g->tokens.length; i += 1) {
-        Token *token = g->tokens.at(i);
-        if (buf_eql_buf(name, &token->name))
-            return token;
-    }
-    return nullptr;
-}
-
-static Token *find_or_create_token(Gen *g, Buf *name) {
-    Token *token = find_token_by_name(g, name);
-    if (!token) {
-        token = allocate<Token>(1);
-        token->id = g->tokens.length;
-        buf_init_from_mem(&token->name, buf_ptr(name), buf_len(name));
-        g->tokens.append(token);
-    }
-    return token;
-}
-
-__attribute__ ((format (printf, 2, 3)))
-static void lex_error(Gen *g, const char *format, ...) {
-    int line = g->lex_line + 1;
-    int column = g->lex_column + 1;
-
-    va_list ap;
-    va_start(ap, format);
-    fprintf(stderr, "Grammar Error: Line %d, column %d: ", line, column);
-    vfprintf(stderr, format, ap);
-    fprintf(stderr, "\n");
-    va_end(ap);
-    exit(EXIT_FAILURE);
-}
-
-static void lex_push_stack(Gen *g) {
-    g->lex_stack.append({g->lex_state});
-}
-
-static void lex_pop_stack(Gen *g) {
-    LexStack *entry = &g->lex_stack.last();
-    g->lex_state = entry->state;
-    g->lex_stack.pop();
-}
-
-static RuleNode *create_rule_node(Gen *g) {
-    RuleNode *node = allocate<RuleNode>(1);
-    node->lex_line = g->lex_line;
-    node->lex_column = g->lex_column;
-    return node;
-}
-
-static void begin_rule(Gen *g) {
-    assert(!g->lex_cur_or_rule);
-    assert(!g->lex_cur_tuple_rule);
-
-    g->lex_cur_or_rule = create_rule_node(g);
-    g->lex_cur_or_rule->type = RuleNodeTypeOr;
-
-    g->lex_cur_tuple_rule = create_rule_node(g);
-    g->lex_cur_tuple_rule->type = RuleNodeTypeTuple;
-    g->lex_cur_rule_begin = g->lex_pos;
-}
-
-static void end_rule(Gen *g) {
-    assert(g->lex_cur_or_rule);
-    assert(!g->lex_cur_tuple_rule);
-
-    g->rules.append(g->lex_cur_or_rule);
-    g->lex_cur_or_rule = nullptr;
-}
-
-static void perform_or(Gen *g) {
-    assert(g->lex_cur_or_rule);
-    assert(!g->lex_cur_tuple_rule);
-
-    g->lex_cur_tuple_rule = create_rule_node(g);
-    g->lex_cur_tuple_rule->type = RuleNodeTypeTuple;
-    g->lex_cur_rule_begin = g->lex_pos;
-}
-
-static void end_rule_name(Gen *g) {
-    assert(g->lex_cur_or_rule);
-    char *ptr = &buf_ptr(g->in_buf)[g->lex_cur_rule_begin];
-    int len = g->lex_pos - g->lex_cur_rule_begin;
-    buf_init_from_mem(&g->lex_cur_or_rule->_or.name, ptr, len);
-}
-
-static void begin_rule_field_name(Gen *g) {
-    assert(g->lex_cur_or_rule);
-    g->lex_field_name_begin = g->lex_pos;
-}
-
-static void end_rule_field_name(Gen *g) {
-    assert(g->lex_cur_or_rule);
-    char *ptr = &buf_ptr(g->in_buf)[g->lex_field_name_begin];
-    int len = g->lex_pos - g->lex_field_name_begin;
-    buf_init_from_mem(&g->lex_cur_or_rule->_or.union_field_name, ptr, len);
-}
-
-static void begin_fn_name(Gen *g) {
-    g->lex_fn_name_begin = g->lex_pos;
-    lex_push_stack(g);
-}
-
-static void end_fn_name(Gen *g) {
-    char *ptr = &buf_ptr(g->in_buf)[g->lex_fn_name_begin];
-    int len = g->lex_pos - g->lex_fn_name_begin;
-    if (mem_eql_str(ptr, len, "token")) {
-        g->lex_state = LexStateTokenStart;
-    } else {
-        lex_error(g, "invalid function name: '%s'", buf_ptr(buf_create_from_mem(ptr, len)));
-    }
-}
-
-static void begin_token_name(Gen *g) {
-    g->lex_token_name_begin = g->lex_pos;
-}
-
-static void end_token_name(Gen *g) {
-    assert(g->lex_cur_tuple_rule);
-    assert(g->lex_cur_tuple_rule->type == RuleNodeTypeTuple);
-
-    char *ptr = &buf_ptr(g->in_buf)[g->lex_token_name_begin];
-    int len = g->lex_pos - g->lex_token_name_begin;
-    Buf token_name = {0};
-    buf_init_from_mem(&token_name, ptr, len);
-
-    Token *token = find_or_create_token(g, &token_name);
-    RuleNode *node = create_rule_node(g);
-    node->type = RuleNodeTypeToken;
-    node->token.token = token;
-
-    g->lex_cur_tuple_rule->tuple.children.append(node);
-
-
-    lex_pop_stack(g);
-}
-
-static void begin_tuple_body(Gen *g) {
-    assert(g->lex_cur_tuple_rule->type == RuleNodeTypeTuple);
-    g->lex_body_begin = g->lex_pos;
-}
-
-static void end_tuple_body(Gen *g) {
-    assert(g->lex_cur_or_rule);
-    assert(g->lex_cur_tuple_rule->type == RuleNodeTypeTuple);
-    int end_pos = g->lex_pos + 1;
-    char *ptr = &buf_ptr(g->in_buf)[g->lex_body_begin];
-    int len = end_pos - g->lex_body_begin;
-    buf_init_from_mem(&g->lex_cur_tuple_rule->tuple.body, ptr, len);
-
-    g->lex_cur_or_rule->_or.children.append(g->lex_cur_tuple_rule);
-    g->lex_cur_tuple_rule = nullptr;
-}
-
-static void begin_sub_tuple(Gen *g) {
-    g->lex_sub_tuple_begin = g->lex_pos;
-    lex_push_stack(g);
-}
-
-static void end_sub_tuple(Gen *g) {
-    assert(g->lex_cur_tuple_rule->type == RuleNodeTypeTuple);
-    char *ptr = &buf_ptr(g->in_buf)[g->lex_sub_tuple_begin];
-    int len = g->lex_pos - g->lex_sub_tuple_begin;
-
-    RuleNode *node = create_rule_node(g);
-    node->type = RuleNodeTypeSubRule;
-    buf_init_from_mem(&node->sub_rule.name, ptr, len);
-
-    g->lex_cur_tuple_rule->tuple.children.append(node);
-
-    lex_pop_stack(g);
-}
-
-static RuleNode *find_rule_node(Gen *g, Buf *name) {
-    for (int i = 0; i < g->rules.length; i += 1) {
-        RuleNode *node = g->rules.at(i);
-        assert(node->type == RuleNodeTypeOr);
-        if (buf_eql_buf(&node->_or.name, name)) {
-            return node;
-        }
-    }
-    return nullptr;
-}
-
-static void initialize_rules(Gen *g) {
-    g->lex_state = LexStateStart;
-    for (g->lex_pos = 0; g->lex_pos < buf_len(g->in_buf); g->lex_pos += 1) {
-        uint8_t c = buf_ptr(g->in_buf)[g->lex_pos];
-        switch (g->lex_state) {
-            case LexStateStart:
-                switch (c) {
-                    case WHITESPACE:
-                        // ignore
-                        break;
-                    case UPPER_ALPHA:
-                        begin_rule(g);
-                        g->lex_state = LexStateRuleName;
-                        break;
-                    default:
-                        lex_error(g, "invalid char: '%c'", c);
-                }
-                break;
-            case LexStateRuleName:
-                switch (c) {
-                    case '<':
-                        end_rule_name(g);
-                        g->lex_state = LexStateRuleFieldNameStart;
-                        break;
-                    case SYMBOL_CHAR:
-                        // ok
-                        break;
-                    default:
-                        lex_error(g, "expected '<', not '%c'", c);
-                }
-                break;
-            case LexStateRuleFieldNameStart:
-                switch (c) {
-                    case SYMBOL_CHAR:
-                        begin_rule_field_name(g);
-                        g->lex_state = LexStateRuleFieldName;
-                        break;
-                    default:
-                        lex_error(g, "expected field name, not '%c'", c);
-                }
-                break;
-            case LexStateRuleFieldName:
-                switch (c) {
-                    case SYMBOL_CHAR:
-                        // ok
-                        break;
-                    case '>':
-                        end_rule_field_name(g);
-                        g->lex_state = LexStateWaitForColon;
-                        break;
-                }
-                break;
-            case LexStateWaitForColon:
-                switch (c) {
-                    case WHITESPACE:
-                        // ignore
-                        break;
-                    case ':':
-                        g->lex_state = LexStateTupleRule;
-                        break;
-                    default:
-                        lex_error(g, "invalid char: '%c'", c);
-                }
-                break;
-            case LexStateTupleRule:
-                switch (c) {
-                    case WHITESPACE:
-                        // ignore
-                        break;
-                    case LOWER_ALPHA:
-                        begin_fn_name(g);
-                        g->lex_state = LexStateFnName;
-                        break;
-                    case UPPER_ALPHA:
-                        begin_sub_tuple(g);
-                        g->lex_state = LexStateSubTupleName;
-                        break;
-                    case '{':
-                        begin_tuple_body(g);
-                        g->lex_state = LexStateBody;
-                        break;
-                    default:
-                        lex_error(g, "expected rule, not '%c'", c);
-                }
-                break;
-            case LexStateFnName:
-                switch (c) {
-                    case LOWER_ALPHA:
-                        // ignore
-                        break;
-                    case '(':
-                        end_fn_name(g);
-                        break;
-                    default:
-                        lex_error(g, "expected '('");
-                }
-                break;
-            case LexStateTokenStart:
-                switch (c) {
-                    case WHITESPACE:
-                        // ignore
-                        break;
-                    case ALPHA:
-                        begin_token_name(g);
-                        g->lex_state = LexStateToken;
-                        break;
-                    default:
-                        lex_error(g, "expected token name, not '%c'", c);
-                }
-                break;
-            case LexStateToken:
-                switch (c) {
-                    case ALPHA:
-                        // ignore
-                        break;
-                    case ')':
-                        end_token_name(g);
-                        break;
-                    default:
-                        lex_error(g, "expected token name or ')', not '%c'", c);
-                }
-                break;
-            case LexStateBody:
-                switch (c) {
-                    case '}':
-                        end_tuple_body(g);
-                        g->lex_state = LexStateEndOrOr;
-                        break;
-                    default:
-                        // ignore
-                        break;
-                }
-                break;
-            case LexStateEndOrOr:
-                switch (c) {
-                    case WHITESPACE:
-                        // ignore
-                        break;
-                    case ';':
-                        end_rule(g);
-                        g->lex_state = LexStateStart;
-                        break;
-                    case '|':
-                        perform_or(g);
-                        g->lex_state = LexStateTupleRule;
-                        break;
-                    default:
-                        lex_error(g, "expected ';' or '|'");
-                }
-                break;
-            case LexStateSubTupleName:
-                switch (c) {
-                    case ALPHA:
-                        // ignore
-                        break;
-                    case WHITESPACE:
-                        end_sub_tuple(g);
-                        assert(g->lex_state == LexStateTupleRule);
-                        break;
-                    default:
-                        lex_error(g, "expected rule name, not '%c'", c);
-                }
-                break;
-        }
-        if (c == '\n') {
-            g->lex_line += 1;
-            g->lex_column = 0;
-        } else {
-            g->lex_column += 1;
-        }
-    }
-    switch (g->lex_state) {
-        case LexStateStart:
-            // ok
-            break;
-        case LexStateEndOrOr:
-        case LexStateRuleName:
-        case LexStateWaitForColon:
-        case LexStateTupleRule:
-        case LexStateFnName:
-        case LexStateTokenStart:
-        case LexStateToken:
-        case LexStateBody:
-        case LexStateSubTupleName:
-        case LexStateRuleFieldNameStart:
-        case LexStateRuleFieldName:
-            lex_error(g, "unexpected EOF");
-            break;
-    }
-
-    // Iterate over the rules and
-    //  * resolve child references into pointers
-    //  * calculate the biggest tuple len
-    bool any_errors = false;
-    for (int or_i = 0; or_i < g->rules.length; or_i += 1) {
-        RuleNode *or_node = g->rules.at(or_i);
-        assert(or_node->type == RuleNodeTypeOr);
-
-        for (int tuple_i = 0; tuple_i < or_node->_or.children.length; tuple_i += 1) {
-            RuleNode *tuple_node = or_node->_or.children.at(tuple_i);
-            assert(tuple_node->type == RuleNodeTypeTuple);
-            g->biggest_tuple_len = max(g->biggest_tuple_len, tuple_node->tuple.children.length);
-
-            for (int child_i = 0; child_i < tuple_node->tuple.children.length; child_i += 1) {
-                RuleNode *child = tuple_node->tuple.children.at(child_i);
-
-                if (child->type == RuleNodeTypeSubRule) {
-                    int line = child->lex_line + 1;
-                    int column = child->lex_column + 1;
-                    RuleNode *referenced_node = find_rule_node(g, &child->sub_rule.name);
-                    if (!referenced_node) {
-                        fprintf(stderr, "Grammar Error: Line %d, column %d: Rule not defined: '%s'\n",
-                                line, column, buf_ptr(&child->sub_rule.name));
-                        any_errors = true;
-                    }
-                    child->sub_rule.child = referenced_node;
-                }
-            }
-        }
-    }
-
-    if (any_errors) {
-        exit(EXIT_FAILURE);
-    }
-}
-
-enum TemplateState {
-    TemplateStateStart,
-    TemplateStateDollar,
-    TemplateStateNumber,
-};
-
-static Buf *fill_template(Buf *body, const char *result_name, Buf *field_names) {
-    //fprintf(stderr, "fill template input:\n%s\n", buf_ptr(body));
-    Buf *result = buf_alloc();
-    TemplateState state = TemplateStateStart;
-    int digit_start;
-    for (int i = 0; i < buf_len(body); i += 1) {
-        uint8_t c = buf_ptr(body)[i];
-        switch (state) {
-            case TemplateStateStart:
-                switch (c) {
-                    case '$':
-                        state = TemplateStateDollar;
-                        break;
-                    default:
-                        buf_append_char(result, c);
-                        break;
-                }
-                break;
-            case TemplateStateDollar:
-                switch (c) {
-                    case '$':
-                        buf_append_str(result, result_name);
-                        state = TemplateStateStart;
-                        break;
-                    case DIGIT:
-                        digit_start = i;
-                        state = TemplateStateNumber;
-                        break;
-                    default:
-                        buf_append_char(result, '$');
-                        buf_append_char(result, c);
-                        state = TemplateStateStart;
-                        break;
-                }
-                break;
-            case TemplateStateNumber:
-                switch (c) {
-                    case DIGIT:
-                        // nothing
-                        break;
-                    default:
-                        {
-                            Buf *num_buf = buf_create_from_mem(&buf_ptr(body)[digit_start], i - digit_start);
-                            int index = atoi(buf_ptr(num_buf)) - 1;
-                            buf_appendf(result, "(top_node->data[%d].%s)%c",
-                                    index, buf_ptr(&field_names[index]), c);
-
-                            state = TemplateStateStart;
-                        }
-                        break;
-                }
-                break;
-        }
-    }
-    switch (state) {
-        case TemplateStateStart:
-            // OK
-            break;
-        default:
-            zig_panic("unable to fill grammar template");
-    }
-    //fprintf(stderr, "fill template output:\n%s\n", buf_ptr(result));
-    return result;
-}
-
-static void build_transition_table(Gen *g, ParserState *state) {
-    if (!state)
-        return;
-    if (state->index >= 0)
-        return;
-    state->index = g->transition_table.length;
-    g->transition_table.append(state);
-    for (int i = 0; i < g->tokens.length; i += 1) {
-        ParserState *other_state = state->transition[i];
-        build_transition_table(g, other_state);
-    }
-}
-
-int main(int argc, char **argv) {
-    const char *in_filename = argv[1];
-    const char *out_filename = argv[2];
-
-    if (!in_filename || !out_filename)
-        return usage(argv[0]);
-
-    FILE *in_f;
-    if (strcmp(in_filename, "-") == 0) {
-        in_f = stdin;
-    } else {
-        in_f = fopen(in_filename, "rb");
-    }
-
-    FILE *out_f;
-    if (strcmp(out_filename, "-") == 0) {
-        out_f = stdout;
-    } else {
-        out_f = fopen(out_filename, "wb");
-    }
-
-    if (!in_f || !out_f)
-        zig_panic("unable to open file(s)");
-
-    Gen g = {0};
-
-    g.in_buf = fetch_file(in_f);
-    initialize_rules(&g);
-
-    g.root = g.rules.at(0);
-
-    g.start_state = create_state(&g);
-    Buf root_field_name = {0};
-    ZigList<ParserState *> end_states = {0};
-    gen(&g, g.root, &root_field_name, g.start_state, &end_states, true);
-    build_transition_table(&g, g.start_state);
-
-    fprintf(out_f, "/* This file is generated by parsergen.cpp */\n");
-    fprintf(out_f, "\n");
-    fprintf(out_f, "#include \"src/parser.hpp\"\n");
-    fprintf(out_f, "#include <stdio.h>\n");
-
-    fprintf(out_f, "\n");
-    fprintf(out_f, "/*\n");
-    fprintf(out_f, "enum TokenId {\n");
-    for (int i = 0; i < g.tokens.length; i += 1) {
-        Token *token = g.tokens.at(i);
-        fprintf(out_f, "    TokenId%s = %d,\n", buf_ptr(&token->name), token->id);
-    }
-    fprintf(out_f, "};\n");
-    fprintf(out_f, "*/\n");
-    for (int i = 0; i < g.tokens.length; i += 1) {
-        Token *token = g.tokens.at(i);
-        fprintf(out_f, "static_assert(TokenId%s == %d, \"wrong token id\");\n",
-                buf_ptr(&token->name), token->id);
-    }
-    fprintf(out_f, "\n");
-
-    fprintf(out_f, "struct ParserGenNode {\n");
-    fprintf(out_f, "    int next_index;\n");
-    fprintf(out_f, "    union {\n");
-    fprintf(out_f, "        Token *token;\n");
-    fprintf(out_f, "        AstNode *node;\n");
-    fprintf(out_f, "    } data[%d];\n", g.biggest_tuple_len);
-    fprintf(out_f, "};\n");
-    fprintf(out_f, "\n");
-
-    fprintf(out_f, "AstNode * ast_parse(Buf *buf, ZigList<Token> *tokens) {\n");
-
-    fprintf(out_f, "    static const int transition[%d][%d] = {\n", g.transition_table.length, g.tokens.length);
-    for (int state_index = 0; state_index < g.transition_table.length; state_index += 1) {
-        ParserState *state = g.transition_table.at(state_index);
-        fprintf(out_f, "        {\n");
-
-        for (int token_id = 0; token_id < g.tokens.length; token_id += 1) {
-            ParserState *dest = state->transition[token_id];
-            fprintf(out_f, "            %d,\n", dest ? dest->index : -1);
-        }
-
-        fprintf(out_f, "        },\n");
-    }
-    fprintf(out_f, "    };\n");
-
-
-    fprintf(out_f, "    int state = 0;\n");
-    fprintf(out_f, "    int token_index = 0;\n");
-    fprintf(out_f, "    Token *token = &tokens->at(token_index);\n");
-    fprintf(out_f, "    AstNode *root = nullptr;\n");
-    fprintf(out_f, "    ZigList<ParserGenNode *> stack = {0};\n");
-    fprintf(out_f, "    ParserGenNode *top_node = nullptr;\n");
-
-    fprintf(out_f, "    for (;;) {\n");
-    fprintf(out_f, "        switch (state) {\n");
-
-    for (int state_i = 0; state_i < g.transition_table.length; state_i += 1) {
-        ParserState *state = g.transition_table.at(state_i);
-        fprintf(out_f, "            case %d: {\n", state_i);
-        for (int code_i = 0; code_i < state->code_gen_list.length; code_i += 1) {
-            CodeGen *code = state->code_gen_list.at(code_i);
-            switch (code->type) {
-                case CodeGenTypeTransition:
-                    fprintf(out_f, "                if (token->id < 0 || token->id >= %d) {\n", g.tokens.length);
-                    fprintf(out_f, "                    ast_invalid_token_error(buf, token);\n");
-                    fprintf(out_f, "                }\n");
-                    fprintf(out_f, "                assert(transition[%d][token->id] >= 0);\n", state->index);
-                    fprintf(out_f, "                assert(transition[%d][token->id] < %d);\n",
-                            state->index, g.transition_table.length);
-                    fprintf(out_f, "                state = transition[%d][token->id];\n", state->index);
-                    break;
-                case CodeGenTypeError:
-                    fprintf(out_f, "                token_index -= 1;\n");
-                    fprintf(out_f, "                token = &tokens->at(token_index);\n");
-                    fprintf(out_f, "                ast_error(token, \"%s\");\n", buf_ptr(code->error.msg));
-                    break;
-                case CodeGenTypeSave:
-                    fprintf(out_f, "                top_node->data[top_node->next_index++].token = token;\n");
-                    break;
-                case CodeGenTypePushNode:
-                    fprintf(out_f, "                top_node = allocate<ParserGenNode>(1);\n");
-                    fprintf(out_f, "                stack.append(top_node);\n");
-                    break;
-                case CodeGenTypeCapture:
-                    if (code->capture.is_root) {
-                        Buf *code_text = fill_template(code->capture.body, "root", code->capture.field_names);
-                        fprintf(out_f, "%s\n", buf_ptr(code_text));
-                        fprintf(out_f, "                return root;\n");
-                    } else {
-                        fprintf(out_f, "                ParserGenNode *parent_node = stack.at(stack.length - 2);\n");
-                        Buf *dest = buf_sprintf("parent_node->data[parent_node->next_index++].%s",
-                                buf_ptr(code->capture.union_field_name));
-                        Buf *code_text = fill_template(code->capture.body, buf_ptr(dest),
-                                code->capture.field_names);
-                        fprintf(out_f, "%s\n", buf_ptr(code_text));
-                    }
-                    break;
-                case CodeGenTypePopNode:
-                    fprintf(out_f, "                stack.pop();\n");
-                    fprintf(out_f, "                top_node = stack.length ? stack.last() : nullptr;\n");
-                    break;
-                case CodeGenTypeEatToken:
-                    fprintf(out_f, "                token_index += 1;\n");
-                    fprintf(out_f, "                token = (token_index < tokens->length) ? &tokens->at(token_index) : nullptr;\n");
-                    break;
-            }
-        }
-        fprintf(out_f, "                break;\n");
-        fprintf(out_f, "            }\n");
-    }
-    fprintf(out_f, "            default:\n");
-    fprintf(out_f, "                zig_panic(\"unreachable\");\n");
-
-    fprintf(out_f, "        }\n");
-    fprintf(out_f, "    }\n");
-    fprintf(out_f, "    zig_panic(\"unreachable\");\n");
-    fprintf(out_f, "}\n");
-
-    return 0;
-}
CMakeLists.txt
@@ -21,7 +21,6 @@ include_directories(
 )
 
 set(GRAMMAR_TXT "${CMAKE_BINARY_DIR}/simple.txt")
-set(PARSER_GENERATED_CPP "${CMAKE_BINARY_DIR}/parser_generated.cpp")
 
 set(ZIG_SOURCES
     "${CMAKE_SOURCE_DIR}/src/buffer.cpp"
@@ -30,13 +29,6 @@ set(ZIG_SOURCES
     "${CMAKE_SOURCE_DIR}/src/parser.cpp"
     "${CMAKE_SOURCE_DIR}/src/tokenizer.cpp"
     "${CMAKE_SOURCE_DIR}/src/util.cpp"
-    ${PARSER_GENERATED_CPP}
-)
-
-set(PARSERGEN_SOURCES
-    "${CMAKE_SOURCE_DIR}/src/parsergen.cpp"
-    "${CMAKE_SOURCE_DIR}/src/util.cpp"
-    "${CMAKE_SOURCE_DIR}/src/buffer.cpp"
 )
 
 set(CONFIGURE_OUT_FILE "${CMAKE_BINARY_DIR}/config.h")
@@ -63,15 +55,3 @@ target_link_libraries(zig LINK_PUBLIC
 )
 install(TARGETS zig DESTINATION bin)
 
-add_executable(parsergen ${PARSERGEN_SOURCES})
-set_target_properties(parsergen PROPERTIES
-    LINKER_LANGUAGE C
-    COMPILE_FLAGS ${EXE_CFLAGS})
-
-
-add_custom_command(
-    OUTPUT ${PARSER_GENERATED_CPP}
-    COMMAND parsergen ARGS ${GRAMMAR_TXT} ${PARSER_GENERATED_CPP}
-    DEPENDS ${GRAMMAR_TXT} ${PARSERGEN_SOURCES}
-    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
-)