Refactor into monorepo

1 files changed, 139 insertions, 0 deletions

diff --git a/pit/src/lexer.c b/pit/src/lexer.c
new file mode 100644
index 0000000..a2b0c7d
--- /dev/null
+++ b/pit/src/lexer.c
@@ -0,0 +1,139 @@
+#include <lcq/pit/utils.h>
+#include <lcq/pit/lexer.h>
+
+const char *PIT_LEX_TOKEN_NAMES[PIT_LEX_TOKEN__SENTINEL] = {
+    /* [PIT_LEX_TOKEN_EOF] = */ "eof",
+    /* [PIT_LEX_TOKEN_LPAREN] = */ "lparen",
+    /* [PIT_LEX_TOKEN_RPAREN] = */ "rparen",
+    /* [PIT_LEX_TOKEN_LSQUARE] = */ "lsquare",
+    /* [PIT_LEX_TOKEN_RSQUARE] = */ "rsquare",
+    /* [PIT_LEX_TOKEN_DOT] = */ "dot",
+    /* [PIT_LEX_TOKEN_QUOTE] = */ "quote",
+    /* [PIT_LEX_TOKEN_INTEGER_LITERAL] = */ "integer_literal",
+    /* [PIT_LEX_TOKEN_STRING_LITERAL] = */ "string_literal",
+    /* [PIT_LEX_TOKEN_SYMBOL] = */ "symbol",
+};
+
+const char *pit_lex_token_name(pit_lex_token t) {
+    return PIT_LEX_TOKEN_NAMES[t];
+}
+
+static bool is_more_input(pit_lexer *st) {
+    return st && st->end < st->len;
+}
+
+static int is_symchar(int c) {
+    return c != '(' && c != ')' && c != '[' && c != ']' && c != '.' && c != '\'' && c != '"'
+        && pit_libc_ctype_isprint(c)
+        && !pit_libc_ctype_isspace(c);
+}
+
+static int is_hexdigit(int c) {
+    return pit_libc_ctype_isdigit(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F');
+}
+
+static char peek(pit_lexer *st) {
+    if (is_more_input(st)) return st->input[st->end];
+    else return 0;
+}
+
+static char advance(pit_lexer *st) {
+    if (is_more_input(st)) {
+        char ret = st->input[st->end++];
+        if (ret == '\n') {
+            st->line += 1;
+            st->column = 0;
+        } else {
+            st->column += 1;
+        }
+        return ret;
+    }
+    else return 0;
+}
+
+static bool match(pit_lexer *st, int (*f)(int)) {
+    if (f(peek(st))) {
+        advance(st);
+        return true;
+    } else return false;
+}
+
+void pit_lex_bytes(pit_lexer *ret, char *buf, i64 len) {
+    ret->len = len;
+    ret->input = buf;
+    ret->start = 0;
+    ret->end = 0;
+    ret->line = ret->start_line = 1;
+    ret->column = ret->start_column = 0;
+    ret->error = NULL;
+}
+
+pit_lex_token pit_lex_next(pit_lexer *st) {
+restart:
+    st->start = st->end;
+    st->start_line = st->line;
+    st->start_column = st->column;
+    char c = advance(st);
+    switch (c) {
+    case 0: return PIT_LEX_TOKEN_EOF;
+    case ';': while (is_more_input(st) && advance(st) != '\n'); goto restart;
+    case '(': return PIT_LEX_TOKEN_LPAREN;
+    case ')': return PIT_LEX_TOKEN_RPAREN;
+    case '[': return PIT_LEX_TOKEN_LSQUARE;
+    case ']': return PIT_LEX_TOKEN_RSQUARE;
+    case '.': return PIT_LEX_TOKEN_DOT;
+    case '\'': return PIT_LEX_TOKEN_QUOTE;
+    case '"':
+        while (peek(st) != '"') {
+            if (peek(st) == '\\') advance(st); /* skip escaped characters */
+            if (!advance(st)) {
+                st->error = "unterminated string";
+                return PIT_LEX_TOKEN_ERROR;
+            }
+        }
+        advance(st);
+        return PIT_LEX_TOKEN_STRING_LITERAL;
+    default: {
+        if (pit_libc_ctype_isspace(c)) goto restart;
+        pit_lex_token ret = PIT_LEX_TOKEN_INTEGER_LITERAL;
+        int num_idx = 0;
+        bool hex = false;
+        bool leading_dash = false;
+        bool zero_prefix = false;
+        if (!is_symchar(c)) {
+            st->error = "unknown character";
+            return PIT_LEX_TOKEN_ERROR;
+        } else {
+            do {
+                leading_dash = false;
+                switch (num_idx) {
+                case 0:
+                    if (c == '0') zero_prefix = true;
+                    else if (c == '-') { leading_dash = true; continue; }
+                    break;
+                case 1:
+                    if (zero_prefix) {
+                        if (c == 'x') { hex = true; continue; }
+                        else if (c == 'o' || c == 'b') continue;
+                    }
+                    break;
+                }
+                if (!(pit_libc_ctype_isdigit(c) || (hex && is_hexdigit(c)))) ret = PIT_LEX_TOKEN_SYMBOL;
+                ++num_idx;
+            } while (c = peek(st), match(st, is_symchar));
+        }
+        if (leading_dash) return PIT_LEX_TOKEN_SYMBOL;
+        return ret;
+    }
+    }
+}
+
+void pit_lex_cstr(pit_lexer *ret, char *buf) {
+    ret->input = buf;
+    ret->len = (i64) pit_libc_string_strlen(buf);
+    ret->start = 0;
+    ret->end = 0;
+    ret->line = ret->start_line = 1;
+    ret->column = ret->start_column = 0;
+    ret->error = NULL;
+}