Add fn:duration:parse for Go-style duration string parsing

builtin/builtin.go

@@ -133,6 +133,7 @@ var (
 		symbols.DurationFromHours:   symbols.NewFunType(ast.DurationBound /* <= */, ast.Float64Bound),
 		symbols.DurationFromMinutes: symbols.NewFunType(ast.DurationBound /* <= */, ast.Float64Bound),
 		symbols.DurationFromSeconds: symbols.NewFunType(ast.DurationBound /* <= */, ast.Float64Bound),
+		symbols.DurationParse:       symbols.NewFunType(ast.DurationBound /* <= */, ast.StringBound),
 	}
 
 	// ReducerFunctions has those built-in functions with are reducers.

functional/functional.go

@@ -839,6 +839,22 @@ func EvalApplyFn(applyFn ast.ApplyFn, subst ast.Subst) (ast.Constant, error) {
 		}
 		return ast.Duration(int64(s * float64(time.Second))), nil
 
+	case symbols.DurationParse.Symbol:
+		if l := len(evaluatedArgs); l != 1 {
+			return ast.Constant{}, fmt.Errorf("fn:duration:parse expected 1 argument, got %d", l)
+		}
+		str, err := evaluatedArgs[0].StringValue()
+		if err != nil {
+			return ast.Constant{}, fmt.Errorf("fn:duration:parse argument must be string: %w", err)
+		}
+		// Go's time.ParseDuration supports: h, m, s, ms, us (or µs), ns
+		// Examples: "1h30m", "500ms", "-2h45m30s", "1.5h"
+		d, err := time.ParseDuration(str)
+		if err != nil {
+			return ast.Constant{}, fmt.Errorf("fn:duration:parse failed: %w", err)
+		}
+		return ast.Duration(int64(d)), nil
+
 	default:
 		return EvalNumericApplyFn(applyFn, subst)
 	}

functional/functional_test.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"math"
 	"testing"
+	"time"
 
 	"github.com/google/mangle/ast"
 	"github.com/google/mangle/parse"
@@ -1503,3 +1504,61 @@ func TestDurationFromUnits(t *testing.T) {
 		})
 	}
 }
+
+func TestDurationParse(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		want    ast.Constant
+		wantErr bool
+	}{
+		// Basic single-unit durations
+		{"hours", "2h", ast.Duration(2 * int64(time.Hour)), false},
+		{"minutes", "30m", ast.Duration(30 * int64(time.Minute)), false},
+		{"seconds", "45s", ast.Duration(45 * int64(time.Second)), false},
+		{"milliseconds", "500ms", ast.Duration(500 * int64(time.Millisecond)), false},
+		{"microseconds_us", "100us", ast.Duration(100 * int64(time.Microsecond)), false},
+		{"microseconds_µs", "100µs", ast.Duration(100 * int64(time.Microsecond)), false},
+		{"nanoseconds", "1000ns", ast.Duration(1000), false},
+
+		// Combined durations (Go-style)
+		{"hours_minutes", "1h30m", ast.Duration(int64(time.Hour) + 30*int64(time.Minute)), false},
+		{"hours_minutes_seconds", "2h45m30s", ast.Duration(2*int64(time.Hour) + 45*int64(time.Minute) + 30*int64(time.Second)), false},
+		{"minutes_seconds", "5m30s", ast.Duration(5*int64(time.Minute) + 30*int64(time.Second)), false},
+
+		// Decimal values
+		{"decimal_hours", "1.5h", ast.Duration(int64(1.5 * float64(time.Hour))), false},
+		{"decimal_seconds", "2.5s", ast.Duration(int64(2.5 * float64(time.Second))), false},
+
+		// Negative durations
+		{"negative_hours", "-2h", ast.Duration(-2 * int64(time.Hour)), false},
+		{"negative_combined", "-1h30m", ast.Duration(-int64(time.Hour) - 30*int64(time.Minute)), false},
+
+		// Zero
+		{"zero", "0s", ast.Duration(0), false},
+
+		// Error cases
+		{"invalid_unit", "5d", ast.Duration(0), true}, // 'd' (days) not supported by Go
+		{"invalid_format", "abc", ast.Duration(0), true},
+		{"empty_string", "", ast.Duration(0), true},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			expr := ast.ApplyFn{symbols.DurationParse, []ast.BaseTerm{ast.String(test.input)}}
+			got, err := EvalApplyFn(expr, ast.ConstSubstMap{})
+			if test.wantErr {
+				if err == nil {
+					t.Errorf("EvalApplyFn(%v) expected error, got %v", expr, got)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("EvalApplyFn(%v) failed with %v", expr, err)
+			}
+			if !got.Equals(test.want) {
+				t.Errorf("EvalApplyFn(%v) = %v, want %v", expr, got, test.want)
+			}
+		})
+	}
+}

go.sum

@@ -2,17 +2,30 @@ bitbucket.org/creachadair/stringset v0.0.11 h1:6Sv4CCv14Wm+OipW4f3tWOb0SQVpBDLW0
 bitbucket.org/creachadair/stringset v0.0.11/go.mod h1:wh0BHewFe+j0HrzWz7KcGbSNpFzWwnpmgPRlB57U5jU=
 github.com/antlr4-go/antlr/v4 v4.13.1 h1:SqQKkuVZ+zWkMMNkjy5FZe5mr5WURWnlpmOuzYWrPrQ=
 github.com/antlr4-go/antlr/v4 v4.13.1/go.mod h1:GKmUxMtwp6ZgGwZSva4eWPC5mS6vUAmOABFgjdkM7Nw=
+github.com/chzyer/logex v1.2.1 h1:XHDu3E6q+gdHgsdTPH6ImJMIp436vR6MPtH8gP05QzM=
 github.com/chzyer/logex v1.2.1/go.mod h1:JLbx6lG2kDbNRFnfkgvh4eRJRPX1QCoOIWomwysCBrQ=
+github.com/chzyer/readline v1.5.1 h1:upd/6fQk4src78LMRzh5vItIt361/o4uq553V8B5sGI=
 github.com/chzyer/readline v1.5.1/go.mod h1:Eh+b79XXUwfKfcPLepksvw2tcLE/Ct21YObkaSkeBlk=
+github.com/chzyer/test v1.0.0 h1:p3BQDXSxOhOG0P9z6/hGnII4LGiEPOYBhs8asl/fC04=
 github.com/chzyer/test v1.0.0/go.mod h1:2JlltgoNkt4TW/z9V/IzDdFaMTM2JPIi26O1pF38GC8=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang/glog v1.2.4 h1:CNNw5U8lSiiBk7druxtSHHTsRWcxKoac6kZKm2peBBc=
 github.com/golang/glog v1.2.4/go.mod h1:6AhwSGph0fcJtXVM/PEHPqZlFeoLxhs7/t5UDAwmO+w=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
 go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
 golang.org/x/exp v0.0.0-20240707233637-46b078467d37 h1:uLDX+AfeFCct3a2C7uIWBKMJIR3CJMhcgfrUAqjRK6w=
 golang.org/x/exp v0.0.0-20240707233637-46b078467d37/go.mod h1:M4RDyNAINzryxdtnbRXRL/OHtkFuWGRjvuhBJpk2IlY=
 golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
 golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+google.golang.org/protobuf v1.34.0 h1:Qo/qEd2RZPCf2nKuorzksSknv0d3ERwp1vFG38gSmH4=
 google.golang.org/protobuf v1.34.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

symbols/symbols.go

@@ -254,6 +254,10 @@ var (
 	DurationFromMinutes = ast.FunctionSym{"fn:duration:from_minutes", 1}
 	// DurationFromSeconds creates a duration from seconds.
 	DurationFromSeconds = ast.FunctionSym{"fn:duration:from_seconds", 1}
+	// DurationParse parses a Go-style duration string like "1h30m", "500ms", "2h45m30s".
+	// Format: [+-]<value><unit>[<value><unit>...]
+	// Units: h (hours), m (minutes), s (seconds), ms (milliseconds), us/µs (microseconds), ns (nanoseconds)
+	DurationParse = ast.FunctionSym{"fn:duration:parse", 1}
 
 	// PairType is a constructor for a pair type.
 	PairType = ast.FunctionSym{"fn:Pair", 2}