Import OCC sources to OSMORA.ORG

Signed-off-by: Ian Moffett <ian@osmora.org>
Signed-off-by: Quinn Stephens <quinn@osmora.org>

7 files changed, 606 insertions, 0 deletions

diff --git a/src/hash.c b/src/hash.c
new file mode 100644
index 0000000..0e6e879
--- /dev/null
+++ b/src/hash.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "hash.h"
+
+hash_t
+hash(const void *data, size_t len)
+{
+    hash_t hash;
+
+    hash = FNV_OFFSET_BASIS;
+    while (len--) {
+        hash ^= *((uint8_t *)data++);
+        hash *= FNV_PRIME;
+    }
+
+    return hash;
+}
+
+hash_t
+hash_string(const char *str)
+{
+    hash_t hash;
+
+    hash = FNV_OFFSET_BASIS;
+    while (*str) {
+        hash ^= *((uint8_t *)str++);
+        hash *= FNV_PRIME;
+    }
+
+    return hash;
+}
diff --git a/src/hashmap.c b/src/hashmap.c
new file mode 100644
index 0000000..cc7f2db
--- /dev/null
+++ b/src/hashmap.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stddef.h>
+#include "hashmap.h"
+#include "log.h"
+
+void
+hashmap_remove(struct hashmap_entry *entry)
+{
+    list_remove(&entry->list_entry);
+}
+
+void
+hashmap_add(struct hashmap map, struct hashmap_entry *entry)
+{
+    list_prepend(&map.rows[entry->hash % map.row_count], &entry->list_entry);
+}
+
+struct hashmap_entry *
+hashmap_find(struct hashmap map, hash_t hash)
+{
+    struct hashmap_entry *head, *entry;
+
+    entry = head = (struct hashmap_entry *)map.rows[hash % map.row_count].head;
+    do {
+        if (entry->hash == hash) {
+            return entry;
+        }
+
+        entry = (struct hashmap_entry *)entry->list_entry.next;
+    } while (entry != head);
+
+    return NULL;
+}
+
+void
+hashmap_init(struct hashmap map)
+{
+    for (size_t r = 0; r < map.row_count; r++) {
+        list_init(&map.rows[r]);
+    }
+}
diff --git a/src/lexer/char_info.c b/src/lexer/char_info.c
new file mode 100644
index 0000000..d66c651
--- /dev/null
+++ b/src/lexer/char_info.c
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "lexer/char_info.h"
+
+uint8_t char_info[CHAR_INFO_COUNT] = {
+    /*
+        NUL SOH STX ETX
+        EOT ENQ ACK BEL
+        BS  TAB LF  VT
+        FF  CR  SO  SI
+    */
+    0           , 0           , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+    0           , CHAR_HORZ_WS, CHAR_VERT_WS, CHAR_VERT_WS,
+    CHAR_VERT_WS, CHAR_HORZ_WS, 0           , 0           ,
+
+    /*
+        DLE DC1 DC2 DC3
+        DC4 NAK SYN ETB
+        CAN EM  SUB ESC
+        FS  GS  RS  US
+    */
+    0           , 0           , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+
+    /*
+          ! " #
+        $ % & '
+        ( ) * +
+        , - . /
+    */
+    CHAR_HORZ_WS, 0           , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+
+    /*
+        0 1 2 3
+        4 5 6 7
+        8 9 : ;
+        < = > ?
+    */
+    CHAR_DIGIT  , CHAR_DIGIT  , CHAR_DIGIT  , CHAR_DIGIT  ,
+    CHAR_DIGIT  , CHAR_DIGIT  , CHAR_DIGIT  , CHAR_DIGIT  ,
+    CHAR_DIGIT  , CHAR_DIGIT  , 0           , 0           ,
+    0           , 0           , 0           , 0           ,
+
+    /*
+        @ A B C
+        D E F G
+        H I J K
+        L M N O
+    */
+    0           , CHAR_XUPPER , CHAR_XUPPER , CHAR_XUPPER ,
+    CHAR_XUPPER , CHAR_XUPPER , CHAR_XUPPER , CHAR_UPPER  ,
+    CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  ,
+    CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  ,
+
+    /*
+        P Q R S
+        T U V W
+        X Y Z [
+        \ ] ^ _
+    */
+    CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  ,
+    CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  ,
+    CHAR_UPPER  , CHAR_UPPER  , CHAR_UPPER  , 0           ,
+    0           , 0           , 0           , 0           ,
+
+    /*
+        ` a b c
+        d e f g
+        h i j k
+        l m n o
+    */
+    0           , CHAR_XLOWER , CHAR_XLOWER , CHAR_XLOWER ,
+    CHAR_XLOWER , CHAR_XLOWER , CHAR_XLOWER , CHAR_LOWER  ,
+    CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  ,
+    CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  ,
+
+    /*
+        p q r s
+        t u v w
+        x y z {
+        | } ~ DEL
+    */
+    CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  ,
+    CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  ,
+    CHAR_LOWER  , CHAR_LOWER  , CHAR_LOWER  , 0           ,
+    0           , 0           , 0           , 0           ,
+};
diff --git a/src/lexer/keywords.c b/src/lexer/keywords.c
new file mode 100644
index 0000000..7bb6b47
--- /dev/null
+++ b/src/lexer/keywords.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <string.h>
+#include "hash.h"
+#include "lexer/keywords.h"
+#include "log.h"
+
+#define KEYWORD_COUNT 1
+
+#define KEYWORD_MAP_ROWS 16
+
+static struct list map_rows[KEYWORD_MAP_ROWS];
+static struct hashmap map;
+
+static struct {
+    const char *str;
+    enum token_kind value;
+} info[KEYWORD_COUNT] = {
+    { "void", TK_VOID }
+};
+
+static void
+add_keyword(const char *str, enum token_kind value)
+{
+    struct keyword *kwd;
+
+    kwd = malloc(sizeof(struct keyword));
+    if (kwd == NULL) {
+        log_error("Failed to allocate memory for keyword \"%s\"\n", str);
+        return;
+    }
+
+    kwd->len = strlen(str);
+    kwd->value = value;
+
+    kwd->hashmap_entry.hash = hash(str, kwd->len);
+    hashmap_add(map, &kwd->hashmap_entry);
+}
+
+struct keyword *
+keywords_find(struct token *tok)
+{
+    struct keyword *kwd;
+
+    kwd = (struct keyword *)hashmap_find(map, tok->hash);
+
+    /* Check that the lengths match just in case */
+    if (kwd != NULL && kwd->len == tok->len) {
+        return kwd;
+    }
+
+    return NULL;
+}
+
+void
+keywords_init(void)
+{
+    log_debug("Initializing keywords...\n");
+
+    /* Intiailize hashmap */
+    map.rows = map_rows;
+    map.row_count = KEYWORD_MAP_ROWS;
+    hashmap_init(map);
+
+    /* Register all keywords */
+    for (int k = 0; k < KEYWORD_COUNT; k++) {
+        add_keyword(info[k].str, info[k].value);
+    }
+}
diff --git a/src/lexer/lexer.c b/src/lexer/lexer.c
new file mode 100644
index 0000000..183bd76
--- /dev/null
+++ b/src/lexer/lexer.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "lexer.h"
+#include "lexer/char_info.h"
+#include "lexer/keywords.h"
+#include "log.h"
+
+static void
+skip_whitespace(struct lexer *ctx)
+{
+    while (char_info[(int)*ctx->pos] & CHAR_WHITESPACE) {
+        if (char_info[(int)*ctx->pos] & CHAR_VERT_WS) {
+            ctx->line++;
+            ctx->line_start = ctx->pos + 1;
+        }
+
+        ctx->pos++;
+    }
+}
+
+static void
+lex_identifier(struct lexer *ctx, struct token *tok)
+{
+    struct keyword *kwd;
+
+    /* Find end of identifier */
+    ctx->pos++;
+    while (char_info[(int)*ctx->pos] & CHAR_ALNUM || *ctx->pos == '_') {
+        ctx->pos++;
+    }
+
+    /* Calculate length and hash */
+    tok->len = (size_t)(ctx->pos - tok->pos);
+    tok->hash = hash(tok->pos, tok->len);
+
+    /* Look for a keyword matching the identifier */
+    kwd = keywords_find(tok);
+    if (kwd != NULL) {
+        tok->kind = kwd->value;
+    } else {
+        tok->kind = TK_IDENTIFIER;
+    }
+}
+
+bool
+lexer_next(struct lexer *ctx, struct token *tok)
+{
+    if (ctx == NULL || tok == NULL) {
+        return false;
+    }
+
+    skip_whitespace(ctx);
+
+    tok->pos = ctx->pos;
+    tok->line = ctx->line;
+    tok->col = (int)(tok->pos - ctx->line_start) + 1;
+
+    if (char_info[(int)*ctx->pos] & CHAR_ALPHA || *ctx->pos == '_') {
+        lex_identifier(ctx, tok);
+        return true;
+    }
+
+    if (*ctx->pos == '\0') {
+        tok->kind = TK_EOF;
+        return true;
+    }
+
+    tok->kind = TK_UNKNOWN;
+    return true;
+}
+
+bool
+lexer_init(struct lexer *ctx, const char *src)
+{
+    log_debug("Initializing lexer...\n");
+
+    if (ctx == NULL || src == NULL) {
+        return false;
+    }
+
+    ctx->pos = src;
+    ctx->line_start = ctx->pos;
+    ctx->line = 1;
+
+    /* TODO: Only do this once */
+    keywords_init();
+
+    return true;
+}
diff --git a/src/log.c b/src/log.c
new file mode 100644
index 0000000..e3cf82f
--- /dev/null
+++ b/src/log.c
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include "log.h"
+
+void
+__log_debug(const char *src, const char *fmt, ...)
+{
+    va_list args;
+
+    fprintf(stderr, "\033[1;90m[debug]\033[0m %s(): ", src);
+    va_start(args, fmt);
+    vprintf(fmt, args);
+    va_end(args);
+}
+
+void
+__log_warn(const char *src, const char *fmt, ...)
+{
+    va_list args;
+
+    fprintf(stderr, "\033[1;93m[warning]\033[0m %s(): ", src);
+    va_start(args, fmt);
+    vfprintf(stderr, fmt, args);
+    va_end(args);
+}
+
+void
+__log_error(const char *src, const char *fmt, ...)
+{
+    va_list args;
+
+    fprintf(stderr, "\033[1;91m[error]\033[0m %s(): ", src);
+    va_start(args, fmt);
+    vfprintf(stderr, fmt, args);
+    va_end(args);
+}
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..e7a3225
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2025 Quinn Stephens and the OSMORA team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "lexer.h"
+#include "log.h"
+
+static const char *src = "void main";
+
+static void
+tok_error(struct token *tok, const char *fmt, ...)
+{
+    va_list args;
+
+    fprintf(stderr, "\033[1;97m%d:%d: \033[1;91merror: \033[0m", tok->line, tok->col);
+    va_start(args, fmt);
+    vfprintf(stderr, fmt, args);
+    va_end(args);
+}
+
+int
+main(int argc, char **argv)
+{
+    struct lexer lexer;
+    struct token tok;
+
+    (void)argc;
+    (void)argv;
+
+    if (!lexer_init(&lexer, src)) {
+        return EXIT_FAILURE;
+    }
+
+    while (lexer_next(&lexer, &tok)) {
+        if (tok.kind == TK_EOF) {
+            return EXIT_SUCCESS;
+        }
+
+        if (tok.kind == TK_UNKNOWN) {
+            tok_error(&tok, "unrecognized token\n");
+            return EXIT_FAILURE;
+        }
+
+        if (tok.kind == TK_VOID) {
+            log_debug("got void\n");
+        } else if (tok.kind == TK_IDENTIFIER) {
+            log_debug("got identifier \"%.*s\"\n", tok.len, tok.pos);
+        }
+    }
+
+    return EXIT_SUCCESS;
+}