code errors - init

src/main/kotlin/blitz/codeerrors/Errors.kt

@@ -0,0 +1,122 @@
+package blitz.codeerrors
+
+import blitz.str.MutMultiLineString
+import blitz.str.MutString
+import blitz.term.AnsiiMode
+import blitz.term.Terminal
+
+object Errors {
+    data class Source(
+        val file: String,
+        val content: MutMultiLineString
+    )
+
+    data class Location(
+        val source: Source,
+        val line: Int,
+        val col: Int,
+        val size: Int,
+    )
+
+    data class Error(
+        val message: String,
+        val level: Level,
+        val loc: Location,
+        val isHint: Boolean = false,
+    ) {
+        enum class Level {
+            INFO,
+            WARN,
+            ERROR,
+            ;
+
+            operator fun plus(other: Level): Level =
+                when (this) {
+                    INFO -> other
+                    WARN -> if (other == ERROR) other else this
+                    ERROR -> this
+                }
+        }
+    }
+
+    data class PrintConfig(
+        val styles: Map<Error.Level, AnsiiMode> = mapOf(
+            Error.Level.INFO to Terminal.COLORS.WHITE.fg,
+            Error.Level.WARN to Terminal.COLORS.YELLOW.fg,
+            Error.Level.ERROR to Terminal.COLORS.RED.fg
+        ),
+        val levelStr: (Error.Level) -> String = {
+            when (it) {
+                Error.Level.INFO -> "note"
+                Error.Level.WARN -> "warning"
+                Error.Level.ERROR -> "error"
+            }
+        },
+        val underlineString: (len: Int) -> String = {
+            if (it == 0) "" else "^" + "~".repeat(it - 1)
+        },
+    )
+
+    fun print(config: PrintConfig, errors: Iterable<Error>) {
+        val bySources = errors.groupBy { it.loc.source }
+        bySources.forEach { (source, errors) ->
+            val worst = errors
+                .map { it.level }
+                .reduce { acc, level -> acc + level }
+            Terminal.errln("File: \"${source.file}\"", config.styles[worst]!!)
+            Terminal.errln("================================================================================", config.styles[worst]!!)
+
+            val perLines = errors
+                .groupBy { it.loc.line }
+                .entries
+                .sortedBy { it.key }
+
+            perLines.forEach { (line, errors) ->
+                errors.asSequence().filterNot { it.isHint }.forEach { err ->
+                    Terminal.err(config.levelStr(err.level), config.styles[err.level]!!, Terminal.STYLES.BOLD)
+                    Terminal.errln(": ${err.message}", Terminal.STYLES.BOLD)
+                }
+
+                val msg = MutMultiLineString(' ')
+                val lineStr = line.toString()
+                msg[1, 2] = lineStr
+                var nextCol = 3 + lineStr.length
+                msg[0, nextCol] = '|' // TODO: print above and below source but dimmed?
+                msg[1, nextCol] = '|'
+                msg[2, nextCol] = '|'
+                nextCol += 2
+                if (line > 0)
+                    msg[0, nextCol] = source.content[line - 1]
+                msg[1, nextCol] = source.content[line]
+
+                // TODO: underline
+
+                // TODO: hints
+
+                Terminal.errln(msg.toString())
+            }
+
+            Terminal.errln("================================================================================", config.styles[worst]!!)
+        }
+    }
+}
+
+fun main() {
+    val source = Errors.Source("main.kt", MutMultiLineString.from("""
+        fn main() {
+            return 1
+        }
+    """.trimIndent(), ' '))
+
+    val errors = listOf(
+        Errors.Error(
+            "Cannot return integer from function with return type void",
+            Errors.Error.Level.ERROR,
+            Errors.Location(source, 1, 11, 1)
+        )
+    )
+
+    val config = Errors.PrintConfig()
+
+    Errors.print(config, errors)
+}

src/main/kotlin/blitz/str/MutMultiLineString.kt

@@ -17,6 +17,16 @@ class MutMultiLineString(
         return lines[row][col]
     }
 
+    /** if out of bounds, extends with @see fill */
+    operator fun get(row: Int): MutString {
+        if (row >= lines.size) {
+            repeat(row - lines.size + 1) {
+                lines.add(MutString(fill = fill))
+            }
+        }
+        return lines[row]
+    }
+
     /** if out of bounds, extends with @see fill */
     operator fun set(row: Int, col: Int, value: Char) {
         if (row >= lines.size) {
@@ -50,4 +60,14 @@ class MutMultiLineString(
 
     override fun toString(): String =
         lines.joinToString(separator = "\n")
+
+    companion object {
+        fun from(str: String, fill: Char): MutMultiLineString {
+            val res = MutMultiLineString(fill)
+            str.lines().forEach {
+                res.lines += MutString(it, fill)
+            }
+            return res
+        }
+    }
 }