init

Author:    Simon <sfja.skp@edu.mercantec.dk>

.clang-format

@@ -0,0 +1,9 @@
+BasedOnStyle: WebKit
+IndentWidth: 4
+ColumnLimit: 80
+IndentCaseLabels: true
+BreakBeforeBraces: Custom
+BraceWrapping:
+    AfterFunction: true
+    SplitEmptyFunction: false
+

.gitignore

@@ -0,0 +1,5 @@
+
+compile_flags.txt
+cli
+*.o
+

Makefile

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+
+CFLAGS = -std=c17 -Wall -Wextra -Wpedantic -Wconversion
+LFLAGS = -lm
+
+SRC = $(wildcard *.c)
+OBJ = $(patsubst %.c, %.o, $(SRC))
+
+HEADERS = $(wildcard *.h)
+
+TARGET = cli
+
+all: compile_flags.txt$(TARGET)
+
+$(TARGET): $(OBJ)
+	gcc $^ -o $@ $(LFLAGS)
+
+%.o: %.c $(HEADERS)
+	gcc $< -c -o $@ $(CFLAGS)
+
+clean:
+	$(RM) *.o $(TARGET)
+
+compile_flags.txt:
+	echo -xc $(CPP_FLAGS) | sed 's/\s\+/\n/g' > compile_flags.txt
+

main.c

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+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef enum {
+    TokenTypeEof,
+    TokenTypeNewline,
+    TokenTypeSemicolon,
+    TokenTypePlus,
+    TokenTypeInt,
+    TokenTypeId,
+} TokenType;
+
+typedef struct {
+    TokenType type;
+    size_t index, length;
+    int line, column;
+} Token;
+
+typedef struct {
+    size_t index;
+    int line, column;
+} LexerPosition;
+
+typedef struct {
+    const char* text;
+    size_t length;
+    LexerPosition position;
+} Lexer;
+
+void construct_lexer(Lexer* self, const char* text, size_t length)
+{
+    *self = (Lexer) {
+        .text = text,
+        .length = length,
+        .position = {
+            .index = 0,
+            .line = 1,
+            .column = 1,
+        },
+    };
+}
+
+bool is_whitespace_char(char c) { return c == ' ' || c == '\t'; }
+bool is_int_char(char c) { return c >= '0' && c <= '9'; }
+bool is_id_char(char c)
+{
+    return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_'
+        || is_int_char(c);
+}
+
+bool lexer_done(const Lexer* self)
+{
+    return self->position.index >= self->length;
+}
+
+void lexer_step(Lexer* self)
+{
+    if (self->text[self->position.index] == '\n') {
+        self->position.line += 1;
+        self->position.column = 1;
+    } else {
+        self->position.column += 1;
+    }
+    self->position.index += 1;
+}
+
+char lexer_current(const Lexer* self)
+{
+    return self->text[self->position.index];
+}
+
+LexerPosition lexer_position(const Lexer* self) { return self->position; }
+
+Token lexer_token_from(const Lexer* self, TokenType type, LexerPosition start)
+{
+    return (Token) {
+        .type = type,
+        .index = start.index,
+        .length = self->position.index,
+        .line = start.line,
+        .column = start.column,
+    };
+}
+
+void lexer_skip_whitespace(Lexer* self)
+{
+    lexer_step(self);
+    while (!lexer_done(self) && is_whitespace_char(lexer_current(self)))
+        lexer_step(self);
+}
+
+Token lexer_make_int_token(Lexer* self)
+{
+    LexerPosition start = self->position;
+    lexer_step(self);
+    while (!lexer_done(self) && is_int_char(lexer_current(self)))
+        lexer_step(self);
+    return lexer_token_from(self, TokenTypeInt, start);
+}
+
+Token lexer_make_id_token(Lexer* self)
+{
+    LexerPosition start = self->position;
+    lexer_step(self);
+    while (!lexer_done(self) && is_id_char(lexer_current(self)))
+        lexer_step(self);
+    return lexer_token_from(self, TokenTypeId, start);
+}
+
+Token lexer_make_static_token(Lexer* self)
+{
+    switch (lexer_current(self)) {
+        case '\n':
+
+        default:
+            printf("unrecognized char '%c'\n", lexer_current(self));
+            exit(EXIT_FAILURE);
+    }
+}
+
+Token lexer_make_token(Lexer* self)
+{
+    if (lexer_done(self)) {
+        return lexer_token_from(self, TokenTypeEof, lexer_position(self));
+    } else if (is_whitespace_char(lexer_current(self))) {
+        lexer_skip_whitespace(self);
+        return lexer_make_token(self);
+    } else if (is_int_char(lexer_current(self))) {
+        return lexer_make_int_token(self);
+    } else if (is_id_char(is_int_char(lexer_current(self)))) {
+        return lexer_make_id_token(self);
+    } else {
+        return lexer_make_static_token(self);
+    };
+}
+
+Token lexer_next(Lexer* self) { return lexer_make_token(self); }
+
+int main() { printf("hello world\n"); }